feat: TODO

works, but leaks memory

.gitignore

@@ -1,3 +1,7 @@
 target/
 
 /.direnv/
+.env
+
+/flamegraph.svg
+/perf.data*

Cargo.lock

@@ -24,53 +24,64 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e16d2d3311acee920a9eb8d33b8cbc1787ce4a264e85f964c2404b969bdcd487"
 
 [[package]]
-name = "archery"
+name = "arbitrary"
-version = "1.2.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8967cd1cc9e9e1954f644e14fbd6042fe9a37da96c52a67e44a2ac18261f8561"
+checksum = "dde20b3d026af13f561bdd0f15edf01fc734f0dafcedbaf42bba506a9517f223"
-dependencies = [
- "static_assertions",
- "triomphe",
-]
 
 [[package]]
 name = "autocfg"
-version = "1.1.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "bitflags"
-version = "2.9.0"
+version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bitflags"
+version = "2.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b8e56985ec62d17e9c1001dc89c88ecd7dc08e47eba5ec7c29c7b5eeecde967"
+
+[[package]]
+name = "bumpalo"
+version = "3.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46c5e41b57b8bba42a04676d81cb89e9ee8e859a1a66f80a5a72e1cb76b34d43"
+dependencies = [
+ "allocator-api2",
+]
 
 [[package]]
 name = "cc"
-version = "1.2.21"
+version = "1.2.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8691782945451c1c383942c4874dbe63814f61cb57ef773cda2972682b7bb3c0"
+checksum = "42bc4aea80032b7bf409b0bc7ccad88853858911b7713a8062fdc0623867bedc"
 dependencies = [
  "shlex",
 ]
 
 [[package]]
 name = "cfg-if"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+checksum = "9555578bc9e57714c812a1f84e4fc5b4d21fcb063490c624de019f7464c91268"
 
 [[package]]
 name = "cfg_aliases"
-version = "0.2.1"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
 
 [[package]]
 name = "clipboard-win"
-version = "5.4.0"
+version = "5.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15efe7a882b08f34e38556b14f2fb3daa98769d06c7f0c1b076dfd0d983bc892"
+checksum = "bde03770d3df201d4fb868f2c9c59e66a3e4e2bd06692a0fe701e7103c7e84d4"
 dependencies = [
  "error-code",
 ]
@@ -84,12 +95,192 @@ dependencies = [
  "unicode-segmentation",
 ]
 
+[[package]]
+name = "convert_case"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baaaa0ecca5b51987b9423ccdc971514dd8b0bb7b4060b983d3664dad3f1f89f"
+dependencies = [
+ "unicode-segmentation",
+]
+
 [[package]]
 name = "countme"
 version = "3.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7704b5fdd17b18ae31c4c1da5a2e0305a2bf17b5249300a9ee9ed7b72114c636"
 
+[[package]]
+name = "cranelift"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0849f998d4e04e6dd056a75268636e39a58ffe57a295bc69d351a424343a79e"
+dependencies = [
+ "cranelift-codegen",
+ "cranelift-frontend",
+ "cranelift-module",
+]
+
+[[package]]
+name = "cranelift-assembler-x64"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ae7b60ec3fd7162427d3b3801520a1908bef7c035b52983cd3ca11b8e7deb51"
+dependencies = [
+ "cranelift-assembler-x64-meta",
+]
+
+[[package]]
+name = "cranelift-assembler-x64-meta"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6511c200fed36452697b4b6b161eae57d917a2044e6333b1c1389ed63ccadeee"
+dependencies = [
+ "cranelift-srcgen",
+]
+
+[[package]]
+name = "cranelift-bforest"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f7086a645aa58bae979312f64e3029ac760ac1b577f5cd2417844842a2ca07f"
+dependencies = [
+ "cranelift-entity",
+]
+
+[[package]]
+name = "cranelift-bitset"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5225b4dec45f3f3dbf383f12560fac5ce8d780f399893607e21406e12e77f491"
+
+[[package]]
+name = "cranelift-codegen"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "858fb3331e53492a95979378d6df5208dd1d0d315f19c052be8115f4efc888e0"
+dependencies = [
+ "bumpalo",
+ "cranelift-assembler-x64",
+ "cranelift-bforest",
+ "cranelift-bitset",
+ "cranelift-codegen-meta",
+ "cranelift-codegen-shared",
+ "cranelift-control",
+ "cranelift-entity",
+ "cranelift-isle",
+ "gimli",
+ "hashbrown 0.15.4",
+ "log",
+ "regalloc2",
+ "rustc-hash 2.1.1",
+ "serde",
+ "smallvec",
+ "target-lexicon",
+ "wasmtime-internal-math",
+]
+
+[[package]]
+name = "cranelift-codegen-meta"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "456715b9d5f12398f156d5081096e7b5d039f01b9ecc49790a011c8e43e65b5f"
+dependencies = [
+ "cranelift-assembler-x64-meta",
+ "cranelift-codegen-shared",
+ "cranelift-srcgen",
+]
+
+[[package]]
+name = "cranelift-codegen-shared"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0306041099499833f167a0ddb707e1e54100f1a84eab5631bc3dad249708f482"
+
+[[package]]
+name = "cranelift-control"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1672945e1f9afc2297f49c92623f5eabc64398e2cb0d824f8f72a2db2df5af23"
+dependencies = [
+ "arbitrary",
+]
+
+[[package]]
+name = "cranelift-entity"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa3cd55eb5f3825b9ae5de1530887907360a6334caccdc124c52f6d75246c98a"
+dependencies = [
+ "cranelift-bitset",
+]
+
+[[package]]
+name = "cranelift-frontend"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "781f9905f8139b8de22987b66b522b416fe63eb76d823f0b3a8c02c8fd9500c7"
+dependencies = [
+ "cranelift-codegen",
+ "log",
+ "smallvec",
+ "target-lexicon",
+]
+
+[[package]]
+name = "cranelift-isle"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a05337a2b02c3df00b4dd9a263a027a07b3dff49f61f7da3b5d195c21eaa633d"
+
+[[package]]
+name = "cranelift-jit"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "593f8ff2c1a1785d9ab61a4b112ec1c9e8a3b976d8857ed1e70a79d4a07dd5ba"
+dependencies = [
+ "anyhow",
+ "cranelift-codegen",
+ "cranelift-control",
+ "cranelift-entity",
+ "cranelift-module",
+ "cranelift-native",
+ "libc",
+ "log",
+ "region",
+ "target-lexicon",
+ "wasmtime-internal-jit-icache-coherence",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "cranelift-module"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9f7a4b804066f3e62d8fc943e25adc135acbb39288aa6c68e67021a9f6a0c58"
+dependencies = [
+ "anyhow",
+ "cranelift-codegen",
+ "cranelift-control",
+]
+
+[[package]]
+name = "cranelift-native"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2eee7a496dd66380082c9c5b6f2d5fa149cec0ec383feec5caf079ca2b3671c2"
+dependencies = [
+ "cranelift-codegen",
+ "libc",
+ "target-lexicon",
+]
+
+[[package]]
+name = "cranelift-srcgen"
+version = "0.122.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b530783809a55cb68d070e0de60cfbb3db0dc94c8850dd5725411422bedcf6bb"
+
 [[package]]
 name = "derive_more"
 version = "2.0.1"
@@ -105,24 +296,18 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bda628edc44c4bb645fbe0f758797143e4e07926f7ebf4e9bdfbd3d2ce621df3"
 dependencies = [
- "convert_case",
+ "convert_case 0.7.1",
  "proc-macro2",
  "quote",
  "syn",
  "unicode-xid",
 ]
 
-[[package]]
-name = "ecow"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54bfbb1708988623190a6c4dbedaeaf0f53c20c6395abd6a01feb327b3146f4b"
-
 [[package]]
 name = "either"
-version = "1.10.0"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11157ac094ffbdde99aa67b23417ebdd801842852b500e395a45a9c0aac03e4a"
+checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
 name = "endian-type"
@@ -138,19 +323,25 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "errno"
-version = "0.3.11"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "976dd42dc7e85965fe702eb8164f21f450704bdde31faefd6471dba214cb594e"
+checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
 name = "error-code"
-version = "3.3.1"
+version = "3.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5d9305ccc6942a704f4335694ecd3de2ea531b114ac2d51f5f843750787a92f"
+checksum = "dea2df4cf52843e0452895c455a1a2cfbb842a1e7329671acf418fdc53ed4c59"
+
+[[package]]
+name = "fallible-iterator"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2acce4a10f12dc2fb14a218589d4f1f62ef011b2d0cc4b3cb1bba8e94da14649"
 
 [[package]]
 name = "fd-lock"
@@ -160,9 +351,15 @@ checksum = "0ce92ff622d6dadf7349484f42c93271a0d49b7cc4d466a936405bacbe10aa78"
 dependencies = [
  "cfg-if",
  "rustix",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "fixedbitset"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
+
 [[package]]
 name = "foldhash"
 version = "0.1.5"
@@ -170,16 +367,27 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
 
 [[package]]
-name = "hashbrown"
+name = "gimli"
-version = "0.14.3"
+version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "290f1a1d9242c78d09ce40a5e87e7554ee637af1351968159f4952f028f75604"
+checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
+dependencies = [
+ "fallible-iterator",
+ "indexmap",
+ "stable_deref_trait",
+]
 
 [[package]]
 name = "hashbrown"
-version = "0.15.3"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "84b26c544d002229e640969970a2e74021aadf6e2f96372b9c58eff97de08eb3"
+checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+
+[[package]]
+name = "hashbrown"
+version = "0.15.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5971ac85611da7067dbfcabef3c70ebb5606018acd9e2a3903a0da507521e0d5"
 dependencies = [
  "allocator-api2",
  "equivalent",
@@ -192,32 +400,17 @@ version = "0.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589533453244b0995c858700322199b2becb13b627df2851f64a2775d024abcf"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
-name = "inkwell"
+name = "indexmap"
-version = "0.6.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e67349bd7578d4afebbe15eaa642a80b884e8623db74b1716611b131feb1deef"
+checksum = "fe4cd85333e22411419a0bcae1297d25e58c9443848b11dc6a86fefe8c78a661"
 dependencies = [
- "either",
+ "equivalent",
- "inkwell_internals",
+ "hashbrown 0.15.4",
- "libc",
- "llvm-sys",
- "once_cell",
- "thiserror 1.0.69",
-]
-
-[[package]]
-name = "inkwell_internals"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f365c8de536236cfdebd0ba2130de22acefed18b1fb99c32783b3840aec5fb46"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
 ]
 
 [[package]]
@@ -230,16 +423,26 @@ dependencies = [
 ]
 
 [[package]]
-name = "lazy_static"
+name = "libc"
-version = "1.5.0"
+version = "0.2.174"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
 
 [[package]]
-name = "libc"
+name = "libm"
-version = "0.2.172"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d750af042f7ef4f724306de029d18836c26c1765a54a6a3f094cbd23a7267ffa"
+checksum = "f9fbbcab51052fe104eb5e5d351cf728d30a5be1fe14d9be8a3b097481fb97de"
+
+[[package]]
+name = "libmimalloc-sys"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "667f4fec20f29dfc6bc7357c582d91796c169ad7e2fce709468aefeb2c099870"
+dependencies = [
+ "cc",
+ "libc",
+]
 
 [[package]]
 name = "linux-raw-sys"
@@ -247,20 +450,6 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
 
-[[package]]
-name = "llvm-sys"
-version = "181.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d320f9d2723c97d4b78f9190a61ed25cc7cfbe456668c08e6e7dd8e50ceb8500"
-dependencies = [
- "anyhow",
- "cc",
- "lazy_static",
- "libc",
- "regex-lite",
- "semver",
-]
-
 [[package]]
 name = "log"
 version = "0.4.27"
@@ -268,10 +457,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
 
 [[package]]
-name = "memchr"
+name = "mach2"
-version = "2.7.4"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+checksum = "d640282b302c0bb0a2a8e0233ead9035e3bed871f0b7e81fe4a1ec829765db44"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "memchr"
+version = "2.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
 
 [[package]]
 name = "memoffset"
@@ -282,6 +480,15 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mimalloc"
+version = "0.1.48"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1ee66a4b64c74f4ef288bcbb9192ad9c3feaad75193129ac8509af543894fd8"
+dependencies = [
+ "libmimalloc-sys",
+]
+
 [[package]]
 name = "nibble_vec"
 version = "0.1.0"
@@ -293,11 +500,11 @@ dependencies = [
 
 [[package]]
 name = "nix"
-version = "0.29.0"
+version = "0.28.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
 dependencies = [
- "bitflags",
+ "bitflags 2.9.1",
  "cfg-if",
  "cfg_aliases",
  "libc",
@@ -305,25 +512,159 @@ dependencies = [
 
 [[package]]
 name = "nixjit"
-version = "0.0.0"
+version = "0.1.0"
 dependencies = [
- "derive_more",
+ "anyhow",
- "ecow",
+ "bumpalo",
- "hashbrown 0.15.3",
+ "mimalloc",
- "inkwell",
+ "nixjit_context",
- "itertools",
+ "nixjit_value",
  "regex",
- "rnix",
- "rpds",
  "rustyline",
- "thiserror 2.0.12",
 ]
 
 [[package]]
-name = "once_cell"
+name = "nixjit_builtins"
-version = "1.21.3"
+version = "0.1.0"
+dependencies = [
+ "nixjit_error",
+ "nixjit_eval",
+ "nixjit_macros",
+ "nixjit_value",
+]
+
+[[package]]
+name = "nixjit_context"
+version = "0.1.0"
+dependencies = [
+ "bumpalo",
+ "cranelift",
+ "cranelift-jit",
+ "cranelift-module",
+ "cranelift-native",
+ "derive_more",
+ "hashbrown 0.15.4",
+ "itertools",
+ "nixjit_builtins",
+ "nixjit_error",
+ "nixjit_eval",
+ "nixjit_hir",
+ "nixjit_ir",
+ "nixjit_jit",
+ "nixjit_lir",
+ "nixjit_value",
+ "petgraph",
+ "replace_with",
+ "rnix",
+]
+
+[[package]]
+name = "nixjit_error"
+version = "0.1.0"
+dependencies = [
+ "rnix",
+ "thiserror",
+]
+
+[[package]]
+name = "nixjit_eval"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "hashbrown 0.15.4",
+ "itertools",
+ "nixjit_error",
+ "nixjit_ir",
+ "nixjit_lir",
+ "nixjit_value",
+ "replace_with",
+ "smallvec",
+]
+
+[[package]]
+name = "nixjit_hir"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "hashbrown 0.15.4",
+ "nixjit_error",
+ "nixjit_ir",
+ "nixjit_macros",
+ "nixjit_value",
+ "rnix",
+]
+
+[[package]]
+name = "nixjit_ir"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "hashbrown 0.15.4",
+ "nixjit_value",
+ "rnix",
+]
+
+[[package]]
+name = "nixjit_jit"
+version = "0.1.0"
+dependencies = [
+ "cranelift",
+ "cranelift-jit",
+ "cranelift-module",
+ "cranelift-native",
+ "hashbrown 0.15.4",
+ "nixjit_error",
+ "nixjit_eval",
+ "nixjit_hir",
+ "nixjit_ir",
+ "nixjit_lir",
+ "nixjit_value",
+]
+
+[[package]]
+name = "nixjit_lir"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "hashbrown 0.15.4",
+ "itertools",
+ "nixjit_error",
+ "nixjit_hir",
+ "nixjit_ir",
+ "nixjit_macros",
+ "nixjit_value",
+ "rnix",
+]
+
+[[package]]
+name = "nixjit_macros"
+version = "0.1.0"
+dependencies = [
+ "convert_case 0.8.0",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "nixjit_value"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "regex",
+]
+
+[[package]]
+name = "petgraph"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+checksum = "54acf3a685220b533e437e264e4d932cfbdc4cc7ec0cd232ed73c08d03b8a7ca"
+dependencies = [
+ "fixedbitset",
+ "hashbrown 0.15.4",
+ "indexmap",
+ "serde",
+]
 
 [[package]]
 name = "proc-macro2"
@@ -353,6 +694,20 @@ dependencies = [
  "nibble_vec",
 ]
 
+[[package]]
+name = "regalloc2"
+version = "0.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5216b1837de2149f8bc8e6d5f88a9326b63b8c836ed58ce4a0a29ec736a59734"
+dependencies = [
+ "allocator-api2",
+ "bumpalo",
+ "hashbrown 0.15.4",
+ "log",
+ "rustc-hash 2.1.1",
+ "smallvec",
+]
+
 [[package]]
 name = "regex"
 version = "1.11.1"
@@ -376,18 +731,30 @@ dependencies = [
  "regex-syntax",
 ]
 
-[[package]]
-name = "regex-lite"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53a49587ad06b26609c52e423de037e7f57f20d53535d66e08c695f347df952a"
-
 [[package]]
 name = "regex-syntax"
 version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
 
+[[package]]
+name = "region"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6b6ebd13bc009aef9cd476c1310d49ac354d36e240cf1bd753290f3dc7199a7"
+dependencies = [
+ "bitflags 1.3.2",
+ "libc",
+ "mach2",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "replace_with"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51743d3e274e2b18df81c4dc6caf8a5b8e15dbe799e0dca05c7617380094e884"
+
 [[package]]
 name = "rnix"
 version = "0.12.0"
@@ -399,26 +766,17 @@ dependencies = [
 
 [[package]]
 name = "rowan"
-version = "0.15.15"
+version = "0.15.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a58fa8a7ccff2aec4f39cc45bf5f985cec7125ab271cf681c279fd00192b49"
+checksum = "d4f1e4a001f863f41ea8d0e6a0c34b356d5b733db50dadab3efef640bafb779b"
 dependencies = [
  "countme",
- "hashbrown 0.14.3",
+ "hashbrown 0.14.5",
  "memoffset",
- "rustc-hash",
+ "rustc-hash 1.1.0",
  "text-size",
 ]
 
-[[package]]
-name = "rpds"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0e15515d3ce3313324d842629ea4905c25a13f81953eadb88f85516f59290a4"
-dependencies = [
- "archery",
-]
-
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -426,25 +784,31 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
 [[package]]
-name = "rustix"
+name = "rustc-hash"
-version = "1.0.7"
+version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c71e83d6afe7ff64890ec6b71d6a69bb8a610ab78ce364b3352876bb4c801266"
+checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
+
+[[package]]
+name = "rustix"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
 dependencies = [
- "bitflags",
+ "bitflags 2.9.1",
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
 name = "rustyline"
-version = "15.0.0"
+version = "14.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ee1e066dc922e513bda599c6ccb5f3bb2b0ea5870a579448f2622993f0a9a2f"
+checksum = "7803e8936da37efd9b6d4478277f4b2b9bb5cdb37a113e8d63222e58da647e63"
 dependencies = [
- "bitflags",
+ "bitflags 2.9.1",
  "cfg-if",
  "clipboard-win",
  "fd-lock",
@@ -457,14 +821,28 @@ dependencies = [
  "unicode-segmentation",
  "unicode-width",
  "utf8parse",
- "windows-sys",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
-name = "semver"
+name = "serde"
-version = "1.0.26"
+version = "1.0.219"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56e6fa9c48d24d85fb3de5ad847117517440f6beceb7798af16b4a87d616b8d0"
+checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.219"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
 
 [[package]]
 name = "shlex"
@@ -474,60 +852,46 @@ checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
 [[package]]
 name = "smallvec"
-version = "1.13.2"
+version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
+checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
 [[package]]
-name = "static_assertions"
+name = "stable_deref_trait"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
+checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 
 [[package]]
 name = "syn"
-version = "2.0.101"
+version = "2.0.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ce2b7fc941b3a24138a0a7cf8e858bfc6a992e7978a068a5c760deb0ed43caf"
+checksum = "17b6f705963418cdb9927482fa304bc562ece2fdd4f616084c50b7023b435a40"
 dependencies = [
  "proc-macro2",
  "quote",
  "unicode-ident",
 ]
 
+[[package]]
+name = "target-lexicon"
+version = "0.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e502f78cdbb8ba4718f566c418c52bc729126ffd16baee5baa718cf25dd5a69a"
+
 [[package]]
 name = "text-size"
 version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f18aa187839b2bdb1ad2fa35ead8c4c2976b64e4363c386d45ac0f7ee85c9233"
 
-[[package]]
-name = "thiserror"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
-dependencies = [
- "thiserror-impl 1.0.69",
-]
-
 [[package]]
 name = "thiserror"
 version = "2.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "567b8a2dae586314f7be2a752ec7474332959c6460e02bde30d702a66d488708"
 dependencies = [
- "thiserror-impl 2.0.12",
+ "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
 ]
 
 [[package]]
@@ -541,12 +905,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "triomphe"
-version = "0.1.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "859eb650cfee7434994602c3a68b25d77ad9e68c8a6cd491616ef86661382eb3"
-
 [[package]]
 name = "unicode-ident"
 version = "1.0.18"
@@ -561,9 +919,9 @@ checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
 
 [[package]]
 name = "unicode-width"
-version = "0.2.0"
+version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fc81956842c57dac11422a97c3b8195a1ff727f06e85c84ed2e8aa277c9a0fd"
+checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
 
 [[package]]
 name = "unicode-xid"
@@ -577,6 +935,36 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "wasmtime-internal-jit-icache-coherence"
+version = "35.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4417e06b7f80baff87d9770852c757a39b8d7f11d78b2620ca992b8725f16f50"
+dependencies = [
+ "anyhow",
+ "cfg-if",
+ "libc",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "wasmtime-internal-math"
+version = "35.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7710d5c4ecdaa772927fd11e5dc30a9a62d1fc8fe933e11ad5576ad596ab6612"
+dependencies = [
+ "libm",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"

Cargo.toml

@@ -1,29 +1,15 @@
-[package]
+[workspace]
-name = "nixjit"
+resolver = "3"
-version = "0.0.0"
+members = [
-edition = "2024"
+    "evaluator/nixjit",
-
+    "evaluator/nixjit_builtins",
-[features]
+    "evaluator/nixjit_context",
-repl = ["dep:rustyline"]
+    "evaluator/nixjit_error",
-
+    "evaluator/nixjit_eval",
-[[bin]]
+    "evaluator/nixjit_hir",
-name = "repl"
+    "evaluator/nixjit_ir",
-required-features = ["repl"]
+    "evaluator/nixjit_jit",
-
+    "evaluator/nixjit_lir",
-[profile.perf]
+    "evaluator/nixjit_macros",
-debug = 1
+    "evaluator/nixjit_value",
-inherits = "release"
+]
-
-[dependencies]
-rnix = "0.12"
-thiserror = "2.0"
-itertools = "0.14"
-rpds = "1.1"
-derive_more = { version = "2.0", features = [ "full" ] }
-ecow = "0.2"
-regex = "1.11"
-hashbrown = "0.15"
-
-inkwell = { version = "0.6.0", features = ["llvm18-1"] }
-
-rustyline = { version = "15.0", optional = true }

TODO.md

@@ -0,0 +1,38 @@
+- [x] downgrade stage
+- [ ] resolve stage
+  - [ ] dynamic attr resolution
+  - [ ] import resolution
+    - [ ] static path resolution
+- [ ] eval stage
+  - [ ] dynamic path resolution
+  - [ ] graph update
+  - [ ] stack storage
+
+依赖类型：
+1. 强依赖 (x!)
+  - builtins.toString x => x!
+  - x + y => x! y!
+  - { x = 1; ${sym} = 2; } => sym!
+2. 弱依赖 a.k.a. thunk (x?)
+  - builtins.seq x y => x! y?
+3. 递归依赖 (x!!)
+  - builtins.deepSeq x y => x!! y?
+
+e.g.
+- let a? = { inherit a?; }; in a! => a!
+  - a! => { a = <THUNK> }
+- f: let x? = f! x?; in x! => f! x!
+- let ret? = (self: { x? = 1; y? = self.x! + 1; }) ret?; in ret.y! => ret! x! y!
+
+工作流程：
+1. string -> AST
+2. AST -> HIR (alloc ExprId)
+3. HIR -> LIR (resolve var, build graph)
+4. LIR -> Value
+
+为每个值分配 ID 的难点在于对动态表达式的引用。
+动态表达式有：
+  - 依赖于函数参数的表达式
+  - 依赖于 with 的表达式
+  - 依赖于动态表达式的表达式
+而这些表达式在每一次分配 ValueId 时指向的 ValueId 都不同，因此需要追踪这些变量。

docs/eval/eval.mmd

@@ -0,0 +1,96 @@
+flowchart TD
+  Start([EvalCtx::eval]) --> Eval[EvalContext::eval]
+  Eval --> AddNode[为本即将求值表达式分配 ValueId，添加至图中]
+  AddNode --> CheckType{检查表达式类型}
+
+  CheckType -->|AttrSet| A_EvalKeys[强制求值所有键]
+  A_EvalKeys --> A_Construct[构造 AttrSet]
+  A_Construct --> End
+  A_EvalKeys -.->|eval| Eval
+
+  CheckType -->|List| L_Construct[构造列表]
+  L_Construct --> End
+
+  CheckType -->|HasAttr| HA_ForceAttrSet[强制求值 AttrSet]
+  HA_ForceAttrSet --> HA_ForceAttrPath[强制求值 AttrPath]
+  HA_ForceAttrPath --> HA_Result[求出结果]
+  HA_Result --> End
+  HA_ForceAttrSet -.->|eval| Eval
+  HA_ForceAttrPath -.->|eval| Eval
+
+  CheckType -->|BinOp| B_ForceLeft[强制求值左操作数]
+  B_ForceLeft --> B_ForceRight[强制求值右操作数]
+  B_ForceRight --> B_Apply[应用操作符]
+  B_Apply --> End
+  B_ForceLeft -.->|eval| Eval
+  B_ForceRight -.->|eval| Eval
+
+  CheckType -->|UnOp| U_ForceOperand[强制求值操作数]
+  U_ForceOperand --> U_Apply[应用操作符]
+  U_Apply --> End
+  U_ForceOperand -.->|eval| Eval
+
+  CheckType -->|Select| S_ForceAttrSet[强制求值 AttrSet]
+  S_ForceAttrSet --> S_ForceAttrPath[强制求值 AttrPath]
+  S_ForceAttrPath --> S_Result[获取结果]
+  S_Result --> End
+  S_ForceAttrSet -.->|eval| Eval
+  S_ForceAttrPath -.->|eval| Eval
+
+  CheckType -->|If| I_ForceCond[强制求值条件]
+  I_ForceCond --> I_Cond{判断条件}
+  I_Cond -->|true| I_Consq[返回 then]
+  I_Cond -->|false| I_Alter[返回 else]
+  I_Consq --> End
+  I_Alter --> End
+  I_ForceCond -.->|eval| Eval
+
+  CheckType -->|Call| C_RegArg[注册函数参数]
+  C_RegArg --> C_ForceBody[强制求值函数体]
+  C_ForceBody --> End
+  C_ForceBody -.->|eval| Eval
+
+  CheckType -->|With| W_ForceNameSpace[强制求值命名空间]
+  W_ForceNameSpace --> W_EnterWith[进入命名空间]
+  W_EnterWith --> W_ForceBody[强制求值表达式]
+  W_ForceBody --> W_ExitWith[退出命名空间]
+  W_ExitWith --> End
+  W_ForceNameSpace -.->|eval| Eval
+  W_ForceBody -.->|eval| Eval
+
+  CheckType -->|Assert| As_ForceCond[强制求值断言]
+  As_ForceCond --> As_Cond{判断断言}
+  As_Cond -->|true| As_ForceBody[强制求值表达式]
+  As_Cond -->|false| As_Throw[抛出 Catchable]
+  As_ForceBody --> End
+  As_ForceCond -.->|eval| Eval
+  As_ForceBody -.->|eval| Eval
+
+  CheckType -->|ConcatStrings| CS_ForceParts[强制求值所有字符串片段]
+  CS_ForceParts --> CS_Construct[构造字符串]
+  CS_Construct --> End
+  CS_ForceParts -.->|eval| Eval
+
+  CheckType -->|Const| Co_Construct[构造常量]
+  Co_Construct --> End
+
+  CheckType -->|Str| St_Construct[构造字符串]
+  St_Construct --> End
+
+  CheckType -->|Var| V_Lookup[动态查找变量]
+  V_Lookup --> End
+
+  CheckType -->|Arg| Ar_Lookup[查找参数]
+  Ar_Lookup --> End
+
+  CheckType -->|Func| F_Construct[构造函数]
+  F_Construct --> End
+
+  CheckType -->|StrictRef| SR_Eval[求值被引用表达式]
+  SR_Eval --> Eval
+
+  CheckType -->|LazyRef| LR_Resolve[解析动态变量引用]
+  LR_Resolve --> LR_Contruct[构造惰性引用]
+  LR_Contruct --> End
+
+  End([返回结果])

docs/resolve/resolve.mmd

@@ -0,0 +1,92 @@
+flowchart TD
+  Start([ResolveCtx::resolve_root]) --> Resolve[ResolveContext::resolve]
+  Resolve --> CheckType{检查表达式类型}
+
+  CheckType -->|AttrSet| A_ResolveKeys[解析所有键]
+  A_ResolveKeys --> A_ResolveValues[解析所有值]
+  A_ResolveValues --> End
+  A_ResolveKeys -.->|resolve| Resolve
+  A_ResolveValues -.->|resolve| Resolve
+
+  CheckType -->|List| L_ResolveElements[解析所有元素]
+  L_ResolveElements --> End
+  L_ResolveElements -.->|resolve| Resolve
+
+  CheckType -->|HasAttr| HA_ResolveAttrSet[解析 AttrSet]
+  HA_ResolveAttrSet --> HA_ResolveAttrPath[解析 AttrPath]
+  HA_ResolveAttrPath --> End
+  HA_ResolveAttrSet -.->|resolve| Resolve
+  HA_ResolveAttrPath -.->|resolve| Resolve
+
+  CheckType -->|BinOp| B_ResolveLeft[解析左操作数]
+  B_ResolveLeft --> B_ResolveRight[解析右操作数]
+  B_ResolveRight --> End
+  B_ResolveLeft -.->|resolve| Resolve
+  B_ResolveRight -.->|resolve| Resolve
+
+  CheckType -->|UnOp| U_ResolveOperand[解析操作数]
+  U_ResolveOperand --> End
+  U_ResolveOperand -.->|resolve| Resolve
+
+  CheckType -->|Select| S_ResolveAttrSet[解析 AttrSet]
+  S_ResolveAttrSet --> S_ResolveAttrPath[解析 AttrPath]
+  S_ResolveAttrPath --> End
+  S_ResolveAttrSet -.->|resolve| Resolve
+  S_ResolveAttrPath -.->|resolve| Resolve
+
+  CheckType -->|If| I_ResolveCond[解析条件]
+  I_ResolveCond --> I_ResolveConsq[解析 then 分支]
+  I_ResolveConsq --> I_ResolveAlter[解析 else 分支]
+  I_ResolveAlter --> End
+  I_ResolveCond -.->|resolve| Resolve
+  I_ResolveConsq -.->|resolve| Resolve
+  I_ResolveAlter -.->|resolve| Resolve
+
+  CheckType -->|Call| C_ResolveFunc[解析函数]
+  C_ResolveFunc --> C_ResolveArg[解析参数]
+  C_ResolveArg --> End
+  C_ResolveFunc -.->|resolve| Resolve
+  C_ResolveArg -.->|resolve| Resolve
+
+  CheckType -->|Let| Le_EnterLet[进入 Let 环境]
+  Le_EnterLet --> Le_ResolveValues[解析所有键]
+  Le_ResolveValues --> Le_ResolveBody[解析表达式]
+  Le_ResolveBody --> Le_ExitLet[退出 Let 环境]
+  Le_ExitLet --> End
+  Le_ResolveValues -.->|resolve| Resolve
+  Le_ResolveBody -.->|resolve| Resolve
+
+  CheckType -->|With| W_ResolveNameSpace[解析命名空间]
+  W_ResolveNameSpace --> W_EnterWith[进入命名空间]
+  W_EnterWith --> W_ResolveBody[解析表达式]
+  W_ResolveBody --> W_ExitWith[退出命名空间]
+  W_ExitWith --> End
+  W_ResolveNameSpace -.->|resolve| Resolve
+  W_ResolveBody -.->|resolve| Resolve
+
+  CheckType -->|Assert| As_ResolveCond[解析断言]
+  As_ResolveCond --> As_ResolveBody[解析表达式]
+  As_ResolveBody --> End
+  As_ResolveCond -.->|resolve| Resolve
+  As_ResolveBody -.->|resolve| Resolve
+
+  CheckType -->|ConcatStrings| CS_ResolveParts[解析所有字符串片段]
+  CS_ResolveParts --> End
+  CS_ResolveParts -.->|resolve| Resolve
+
+  CheckType -->|Const| End
+
+  CheckType -->|Str| End
+
+  CheckType -->|Var| V_Lookup[查找变量]
+  V_Lookup --> End
+
+  CheckType -->|Arg| Ar_Lookup[查找参数]
+  Ar_Lookup --> End
+
+  CheckType -->|Func| F_EnterEnv[进入函数环境]
+  F_EnterEnv --> F_ResolveBody[解析函数体]
+  F_ResolveBody --> F_ExitEnv[退出函数环境]
+  F_ExitEnv --> End
+
+  End([返回结果])

evaluator/nixjit/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "nixjit"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+mimalloc = "0.1"
+
+anyhow = "1.0"
+bumpalo = "3.19"
+regex = "1.11"
+rustyline = "14.0"
+
+nixjit_context = { path = "../nixjit_context" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit/src/lib.rs

@@ -0,0 +1,16 @@
+//! The main library crate for the nixjit interpreter and JIT compiler.
+//!
+//! This crate orchestrates the entire process of parsing, analyzing,
+//! and evaluating Nix expressions. It integrates all the other `nixjit_*`
+//! components to provide a complete Nix evaluation environment.
+
+use mimalloc::MiMalloc;
+
+pub use nixjit_context as context;
+pub use nixjit_value as value;
+
+#[global_allocator]
+static GLOBAL: MiMalloc = MiMalloc;
+
+#[cfg(test)]
+mod test;

evaluator/nixjit/src/main.rs

@@ -0,0 +1,53 @@
+use anyhow::Result;
+use bumpalo::Bump;
+use regex::Regex;
+use rustyline::DefaultEditor;
+use rustyline::error::ReadlineError;
+
+use nixjit::context::Context;
+
+fn main() -> Result<()> {
+    let mut rl = DefaultEditor::new()?;
+    let bump = Bump::new();
+    let mut context = Context::new(&bump);
+    let re = Regex::new(r"^\s*([a-zA-Z_][a-zA-Z0-9_'-]*)\s*=(.*)$").unwrap();
+    loop {
+        let readline = rl.readline("nixjit-repl> ");
+        match readline {
+            Ok(line) => {
+                if line.trim().is_empty() {
+                    continue;
+                }
+                let _ = rl.add_history_entry(line.as_str());
+                if let Some(caps) = re.captures(&line) {
+                    let ident = caps.get(1).unwrap().as_str();
+                    let expr = caps.get(2).unwrap().as_str().trim();
+                    if expr.is_empty() {
+                        eprintln!("Error: missing expression after '='");
+                        continue;
+                    }
+                    if let Err(err) = context.add_binding(ident, expr) {
+                        eprintln!("Error: {}", err);
+                    }
+                } else {
+                    match context.eval(&line) {
+                        Ok(value) => println!("{}", value),
+                        Err(err) => eprintln!("Error: {}", err),
+                    }
+                }
+            }
+            Err(ReadlineError::Interrupted) => {
+                println!();
+            }
+            Err(ReadlineError::Eof) => {
+                println!("CTRL-D");
+                break;
+            }
+            Err(err) => {
+                eprintln!("Error: {:?}", err);
+                break;
+            }
+        }
+    }
+    Ok(())
+}

evaluator/nixjit/src/test.rs

@@ -1,40 +1,21 @@
-extern crate test;
+#![allow(unused_macros)]
 
-use hashbrown::HashMap;
+use std::collections::BTreeMap;
 
-use inkwell::context::Context;
+use bumpalo::Bump;
-use test::{Bencher, black_box};
+use nixjit_context::Context;
-
+use nixjit_value::{AttrSet, Const, List, Symbol, Value};
-use ecow::EcoString;
-use rpds::vector_sync;
-
-use crate::compile::compile;
-use crate::ir::downgrade;
-use crate::ty::public::Symbol;
-use crate::ty::public::*;
-use crate::vm::JITContext;
-
-use super::run;
 
 #[inline]
 fn test_expr(expr: &str, expected: Value) {
-    let downgraded = downgrade(rnix::Root::parse(expr).tree().expr().unwrap()).unwrap();
+    println!("{expr}");
-    let prog = compile(downgraded);
+    assert_eq!(Context::new(&Bump::new()).eval(expr).unwrap(), expected);
-    dbg!(&prog);
-    let ctx = Context::create();
-    let jit = JITContext::new(&ctx);
-    assert_eq!(run(prog, jit).unwrap(), expected);
 }
 
 macro_rules! map {
     ($($k:expr => $v:expr),*) => {
         {
-            #[allow(unused_mut)]
+            BTreeMap::from([$(($k, $v),)*])
-            let mut m = HashMap::new();
-            $(
-                m.insert($k, $v);
-            )*
-            m
         }
     };
 }
@@ -65,19 +46,19 @@ macro_rules! boolean {
 
 macro_rules! string {
     ($e:expr) => {
-        Value::Const(Const::String(EcoString::from($e)))
+        Value::String(String::from($e))
     };
 }
 
 macro_rules! symbol {
     ($e:expr) => {
-        Symbol::from($e.to_string())
+        Symbol::from($e)
     };
 }
 
 macro_rules! list {
     ($($x:tt)*) => (
-        Value::List(List::new(vector_sync![$($x)*]))
+        Value::List(List::new(vec![$($x)*]))
     );
 }
 
@@ -159,6 +140,13 @@ fn test_attrs() {
             symbol!("a") => int!(1)
         },
     );
+    test_expr(
+        "rec { a = 1; b = a; }",
+        attrs! {
+            symbol!("a") => int!(1),
+            symbol!("b") => int!(1)
+        },
+    );
     test_expr("{ a = 1; }.a", int!(1));
     test_expr("{ a = 1; }.b or 1", int!(1));
     test_expr(
@@ -184,11 +172,6 @@ fn test_if() {
     test_expr("if true || false then 1 else 2", int!(1));
 }
 
-#[test]
-fn test_with() {
-    test_expr(r#"with { a = 1; }; a"#, int!(1));
-}
-
 #[test]
 fn test_let() {
     test_expr(r#"let a = 1; in a"#, int!(1));
@@ -198,19 +181,31 @@ fn test_let() {
         r#"let b = "c"; in { a.b = 1; } // { a."a${b}" = 2; }"#,
         attrs! { symbol!("a") => attrs!{ symbol!("ac") => int!(2) } },
     );
+    test_expr(
+        "let f = n: let a = n; f = x: a + x; in f; in f 0 1",
+        int!(1),
+    );
 }
 
 #[test]
 fn test_func() {
     test_expr("(x: x) 1", int!(1));
     test_expr("(x: x) (x: x) 1", int!(1));
-    test_expr("(x: y: x + y) 1 1", int!(2));
+    test_expr("(x: y: x / y) 1 2", int!(0));
     test_expr("({ x, y }: x + y) { x = 1; y = 2; }", int!(3));
     test_expr("({ x, y, ... }: x + y) { x = 1; y = 2; z = 3; }", int!(3));
     test_expr(
         "(inputs@{ x, y, ... }: x + inputs.y) { x = 1; y = 2; z = 3; }",
         int!(3),
     );
+    test_expr(
+        "((f: let x = f x; in x) (self: { x = 1; y = self.x + 1; })).y",
+        int!(2),
+    );
+    test_expr(
+        "let fix = f: let x = f x; in x; in (fix (self: { x = 1; y = self.x + 1; })).y",
+        int!(2),
+    );
 }
 
 #[test]
@@ -219,15 +214,5 @@ fn test_fib() {
     test_expr(
         "let fib = n: if n == 1 || n == 2 then 1 else (fib (n - 1)) + (fib (n - 2)); in fib 30",
         int!(832040),
-    )
+    );
-}
-
-#[bench]
-fn bench_fib(b: &mut Bencher) {
-    b.iter(|| {
-        black_box(test_expr(
-            "let fib = n: if n == 1 || n == 2 then 1 else (fib (n - 1)) + (fib (n - 2)); in fib 20",
-            int!(6765),
-        ))
-    })
 }

evaluator/nixjit_builtins/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "nixjit_builtins"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+nixjit_error = { path = "../nixjit_error" }
+nixjit_eval = { path = "../nixjit_eval" }
+nixjit_macros = { path = "../nixjit_macros" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_builtins/src/lib.rs

@@ -0,0 +1,69 @@
+use nixjit_error::Result;
+use nixjit_eval::{Args, Value};
+use nixjit_macros::builtins;
+
+pub trait BuiltinsContext {}
+
+pub type BuiltinFn<Ctx> = fn(&mut Ctx, Args) -> Result<Value>;
+
+#[builtins]
+pub mod builtins {
+    use std::rc::Rc;
+
+    use nixjit_error::{Error, Result};
+    use nixjit_eval::{List, Value};
+    use nixjit_value::Const;
+
+    use super::BuiltinsContext;
+
+    const TRUE: Const = Const::Bool(true);
+    const FALSE: Const = Const::Bool(false);
+    const NULL: Const = Const::Null;
+
+    fn add(a: Value, b: Value) -> Result<Value> {
+        use Value::*;
+        Ok(match (a, b) {
+            (Int(a), Int(b)) => Int(a + b),
+            (Int(a), Float(b)) => Float(a as f64 + b),
+            (Float(a), Int(b)) => Float(a + b as f64),
+            (Float(a), Float(b)) => Float(a + b),
+            (Int(_), b) => {
+                return Err(Error::eval_error(format!(
+                    "expected an integer but found {}",
+                    b.typename()
+                )));
+            }
+            (Float(_), b) => {
+                return Err(Error::eval_error(format!(
+                    "expected an float but found {}",
+                    b.typename()
+                )));
+            }
+            (a, _) => {
+                return Err(Error::eval_error(format!(
+                    "expected an integer but found {}",
+                    a.typename()
+                )));
+            }
+        })
+    }
+
+    pub fn import(ctx: &mut impl BuiltinsContext, path: Value) -> Result<Value> {
+        todo!()
+    }
+
+    fn elem_at(list: Rc<List>, idx: i64) -> Result<Value> {
+        list.get(idx as usize)
+            .ok_or_else(|| {
+                Error::eval_error(format!(
+                    "'builtins.elemAt' called with index {idx} on a list of size {}",
+                    list.len()
+                ))
+            })
+            .cloned()
+    }
+
+    fn elem(elem: Value, list: Rc<List>) -> Result<Value> {
+        todo!()
+    }
+}

evaluator/nixjit_context/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name = "nixjit_context"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+bumpalo = { version = "3.19", features = ["boxed", "collections"] }
+derive_more = { version = "2.0", features = ["full"] }
+hashbrown = "0.15"
+itertools = "0.14"
+petgraph = "0.8"
+replace_with = "0.1"
+rnix = "0.12"
+
+cranelift = "0.122"
+cranelift-module = "0.122"
+cranelift-jit = "0.122"
+cranelift-native = "0.122"
+
+nixjit_builtins = { path = "../nixjit_builtins" }
+nixjit_error = { path = "../nixjit_error" }
+nixjit_eval = { path = "../nixjit_eval" }
+nixjit_hir = { path = "../nixjit_hir" }
+nixjit_ir = { path = "../nixjit_ir" }
+nixjit_jit = { path = "../nixjit_jit" }
+nixjit_lir = { path = "../nixjit_lir" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_context/src/downgrade.rs

@@ -0,0 +1,76 @@
+use std::cell::RefCell;
+
+use nixjit_error::Result;
+use nixjit_hir::{Downgrade, DowngradeContext, Hir};
+use nixjit_ir::ExprId;
+
+use super::Context;
+
+pub struct DowngradeCtx<'ctx, 'bump> {
+    ctx: &'ctx mut Context<'bump>,
+    irs: Vec<RefCell<Hir>>,
+}
+
+impl<'ctx, 'bump> DowngradeCtx<'ctx, 'bump> {
+    pub fn new(ctx: &'ctx mut Context<'bump>) -> Self {
+        Self {
+            ctx,
+            irs: Vec::new(),
+        }
+    }
+}
+
+impl DowngradeCtx<'_, '_> {
+    fn get_ir(&self, id: ExprId) -> &RefCell<Hir> {
+        // SAFETY: The `ExprId` is guaranteed to be valid and correspond to an expression
+        // allocated within this context, making the raw index access safe.
+        let idx = unsafe { id.raw() } - self.ctx.lirs.len() - self.ctx.hirs.len();
+        if cfg!(debug_assertions) {
+            self.irs.get(idx).unwrap()
+        } else {
+            // SAFETY: The index calculation is guarded by the logic that creates `ExprId`s,
+            // ensuring it's always within the bounds of the `irs` vector in release builds.
+            // The debug build's `unwrap()` serves as a runtime check for this invariant.
+            unsafe { self.irs.get_unchecked(idx) }
+        }
+    }
+}
+
+impl DowngradeContext for DowngradeCtx<'_, '_> {
+    fn new_expr(&mut self, expr: Hir) -> ExprId {
+        self.irs.push(expr.into());
+        self.ctx.alloc_id()
+    }
+
+    fn with_expr_mut<T>(&mut self, id: ExprId, f: impl FnOnce(&mut Hir, &mut Self) -> T) -> T {
+        // SAFETY: This is a common pattern to temporarily bypass the borrow checker.
+        // We are creating a mutable reference to `self` from a raw pointer. This is safe
+        // because `self_mut` is only used within the closure `f`, and we are careful
+        // not to create aliasing mutable references. The `RefCell`'s runtime borrow
+        // checking further ensures that we don't have multiple mutable borrows of the
+        // same `Hir` expression simultaneously.
+        unsafe {
+            let self_mut = &mut *(self as *mut Self);
+            f(&mut self.get_ir(id).borrow_mut(), self_mut)
+        }
+    }
+
+    fn downgrade_root(mut self, root: rnix::ast::Expr) -> Result<ExprId> {
+        let id = root.downgrade(&mut self)?;
+        self.ctx
+            .hirs
+            .extend(self.irs.into_iter().map(RefCell::into_inner));
+        for (idx, ir) in self.ctx.hirs.iter().enumerate() {
+            println!(
+                "{:?} {:#?}",
+                // SAFETY: The index `idx` is obtained from iterating over `self.ctx.hirs`,
+                // so it is guaranteed to be a valid index. The length of `lirs` is added
+                // as an offset to ensure the `ExprId` correctly corresponds to its position
+                // in the combined IR storage.
+                unsafe { ExprId::from_raw(idx + self.ctx.lirs.len()) },
+                &ir
+            );
+        }
+        Ok(id)
+    }
+}

evaluator/nixjit_context/src/eval.rs

@@ -0,0 +1,136 @@
+use std::rc::Rc;
+
+use hashbrown::HashMap;
+use petgraph::prelude::DiGraph;
+
+use nixjit_error::{Error, Result};
+use nixjit_eval::{Args, EvalContext, Evaluate, PrimOpApp, Value, ValueId};
+use nixjit_ir::{ExprId, PrimOpId};
+use nixjit_jit::JITContext;
+use nixjit_lir::Lir;
+
+use super::Context;
+
+enum ValueCache {
+    Expr(ExprId),
+    BlackHole,
+    Value(Value),
+}
+
+impl ValueCache {
+    fn get_or_eval(&mut self, eval: impl FnOnce(ExprId) -> Result<Value>) -> Result<&Value> {
+        match self {
+            &mut Self::Expr(id) => {
+                *self = Self::BlackHole;
+                match eval(id) {
+                    Ok(value) => {
+                        *self = Self::Value(value);
+                        let Self::Value(value) = self else {
+                            unreachable!()
+                        };
+                        Ok(value)
+                    }
+                    Err(err) => Err(err),
+                }
+            }
+            Self::Value(value) => Ok(value),
+            Self::BlackHole => Err(Error::eval_error(format!("infinite recursion encountered"))),
+        }
+    }
+}
+
+pub struct EvalCtx<'ctx, 'bump> {
+    ctx: &'ctx mut Context<'bump>,
+    graph: DiGraph<Vec<ValueId>, ()>,
+    caches: Vec<ValueCache>,
+    with_scopes: Vec<Rc<HashMap<String, Value>>>,
+}
+
+impl<'ctx, 'bump> EvalCtx<'ctx, 'bump> {
+    pub fn new(ctx: &'ctx mut Context<'bump>) -> Self {
+        Self {
+            graph: DiGraph::with_capacity(ctx.graph.node_count(), ctx.graph.edge_count()),
+            caches: Vec::new(),
+            with_scopes: Vec::new(),
+            ctx,
+        }
+    }
+}
+
+impl EvalContext for EvalCtx<'_, '_> {
+    fn eval(&mut self, expr: ExprId) -> Result<Value> {
+        // SAFETY: The `expr` `ExprId` is guaranteed to be a valid index into the `lirs`
+        // vector by the `downgrade` and `resolve` stages, which are responsible for
+        // creating and managing these IDs. The `get_unchecked` is safe under this invariant.
+        // The subsequent raw pointer operations are to safely extend the lifetime of the
+        // `Lir` reference. This is sound because the `lirs` vector is allocated within a
+        // `Bump` arena, ensuring that the `Lir` objects have a stable memory location
+        // and will not be deallocated or moved for the lifetime of the context.
+        let idx = unsafe { expr.raw() };
+        let lir = unsafe { &*(&**self.ctx.lirs.get_unchecked(idx) as *const Lir) };
+        lir.eval(self)
+    }
+
+    fn resolve(&mut self, id: ExprId) -> Result<ValueId> {
+        let mut deps = Vec::new();
+
+        self.caches.push(ValueCache::Expr(id));
+        let id = self.graph.add_node(deps);
+
+        // SAFETY: The `id.index()` is guaranteed to be a valid raw ID for a `ValueId`
+        // because it is generated by the `petgraph::DiGraph`, which manages its own
+        // internal indices. This ensures that the raw value is unique and corresponds
+        // to a valid node in the graph.
+        Ok(unsafe { ValueId::from_raw(id.index()) })
+    }
+
+    fn call(&mut self, func: ValueId, arg: Value) -> Result<Value> {
+        todo!()
+    }
+
+    fn force(&mut self, id: ValueId) -> Result<Value> {
+        todo!()
+    }
+
+    fn lookup_with<'a>(&'a self, ident: &str) -> Option<&'a Value> {
+        for scope in self.with_scopes.iter().rev() {
+            if let Some(val) = scope.get(ident) {
+                return Some(val);
+            }
+        }
+        None
+    }
+
+    fn call_primop(&mut self, id: PrimOpId, args: Args) -> Result<Value> {
+        // SAFETY: The `PrimOpId` is created and managed by the `Context` and is
+        // guaranteed to be a valid index into the `primops` array. The `get_unchecked`
+        // is safe under this invariant, avoiding a bounds check for performance.
+        let &(arity, primop) = unsafe { self.ctx.primops.get_unchecked(id.raw()) };
+        if args.len() == arity {
+            primop(self.ctx, args)
+        } else {
+            Ok(Value::PrimOpApp(PrimOpApp::new(id, args).into()))
+        }
+    }
+
+    fn with_with_env<T>(
+        &mut self,
+        namespace: Rc<HashMap<String, Value>>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T {
+        self.with_scopes.push(namespace);
+        let res = f(self);
+        self.with_scopes.pop();
+        res
+    }
+}
+
+impl JITContext for EvalCtx<'_, '_> {
+    fn enter_with(&mut self, namespace: Rc<HashMap<String, Value>>) {
+        self.with_scopes.push(namespace);
+    }
+
+    fn exit_with(&mut self) {
+        self.with_scopes.pop();
+    }
+}

evaluator/nixjit_context/src/lib.rs

@@ -0,0 +1,216 @@
+use std::ptr::NonNull;
+
+use bumpalo::{Bump, boxed::Box};
+use hashbrown::HashMap;
+use itertools::Itertools;
+use petgraph::graphmap::DiGraphMap;
+
+use nixjit_builtins::{
+    builtins::{GLOBAL_LEN, SCOPED_LEN}, BuiltinFn, Builtins, BuiltinsContext
+};
+use nixjit_error::{Error, Result};
+use nixjit_eval::{Args, EvalContext, Value};
+use nixjit_hir::{DowngradeContext, Hir};
+use nixjit_ir::{AttrSet, ExprId, Param, PrimOpId};
+use nixjit_lir::Lir;
+
+use crate::downgrade::DowngradeCtx;
+use crate::eval::EvalCtx;
+use crate::resolve::ResolveCtx;
+
+mod downgrade;
+mod eval;
+mod resolve;
+
+/// The main evaluation context.
+///
+/// This struct orchestrates the entire Nix expression evaluation process,
+/// from parsing and semantic analysis to interpretation and JIT compilation.
+pub struct Context<'bump> {
+    ir_count: usize,
+    hirs: Vec<Hir>,
+    lirs: Vec<Box<'bump, Lir>>,
+    /// Maps a function's body `ExprId` to its parameter definition.
+    funcs: HashMap<ExprId, Param>,
+
+    repl_scope: NonNull<HashMap<String, ExprId>>,
+    global_scope: NonNull<HashMap<&'static str, ExprId>>,
+
+    /// A dependency graph between expressions.
+    graph: DiGraphMap<ExprId, ()>,
+
+    /// A table of primitive operation implementations.
+    primops: [(usize, BuiltinFn<Self>); GLOBAL_LEN + SCOPED_LEN],
+
+    bump: &'bump Bump,
+}
+
+impl Drop for Context<'_> {
+    fn drop(&mut self) {
+        // SAFETY: `repl_scope` and `global_scope` are `NonNull` pointers to `HashMap`s
+        // allocated within the `bump` arena. Because `NonNull` does not convey ownership,
+        // Rust's drop checker will not automatically drop the pointed-to `HashMap`s when
+        // the `Context` is dropped. We must manually call `drop_in_place` to ensure
+        // their destructors are run. This is safe because these pointers are guaranteed
+        // to be valid and non-null for the lifetime of the `Context`, as they are
+        // initialized in `new()` and never deallocated or changed.
+        unsafe {
+            self.repl_scope.drop_in_place();
+            self.global_scope.drop_in_place();
+        }
+    }
+}
+
+impl<'bump> Context<'bump> {
+    pub fn new(bump: &'bump Bump) -> Self {
+        let Builtins { global, scoped } = Builtins::new();
+        let global_scope = global
+            .iter()
+            .enumerate()
+            .map(|(idx, (k, _, _))| {
+                // SAFETY: The index `idx` comes from `enumerate()` on the `global` array,
+                // so it is guaranteed to be a valid, unique index for a primop LIR.
+                (*k, unsafe { ExprId::from_raw(idx) })
+            })
+            .chain(core::iter::once((
+                "builtins",
+                // SAFETY: This ID corresponds to the `builtins` attrset LIR, which is
+                // constructed and placed after all the global and scoped primop LIRs.
+                // The index is calculated to be exactly at that position.
+                unsafe { ExprId::from_raw(GLOBAL_LEN + SCOPED_LEN) },
+            )))
+            .collect();
+        let primops = global
+            .iter()
+            .map(|&(_, arity, f)| (arity, f))
+            .chain(scoped.iter().map(|&(_, arity, f)| (arity, f)))
+            .collect_array()
+            .unwrap();
+        let lirs = (0..global.len())
+            .map(|idx| {
+                // SAFETY: The index `idx` is guaranteed to be within the bounds of the
+                // `global` primops array, making it a valid raw ID for a `PrimOpId`.
+                Lir::PrimOp(unsafe { PrimOpId::from_raw(idx) })
+            })
+            .chain((0..scoped.len()).map(|idx| {
+                // SAFETY: The index `idx` is within the bounds of the `scoped` primops
+                // array. Adding `GLOBAL_LEN` correctly offsets it to its position in
+                // the combined `primops` table.
+                Lir::PrimOp(unsafe { PrimOpId::from_raw(idx + GLOBAL_LEN) })
+            }))
+            .chain(core::iter::once(Lir::AttrSet(AttrSet {
+                stcs: global
+                    .into_iter()
+                    .enumerate()
+                    .map(|(idx, (name, ..))| {
+                        // SAFETY: `idx` from `enumerate` is a valid index for the LIR
+                        // corresponding to this global primop.
+                        (name.to_string(), unsafe { ExprId::from_raw(idx) })
+                    })
+                    .chain(scoped.into_iter().enumerate().map(|(idx, (name, ..))| {
+                        // SAFETY: `idx + GLOBAL_LEN` is a valid index for the LIR
+                        // corresponding to this scoped primop.
+                        (name.to_string(), unsafe {
+                            ExprId::from_raw(idx + GLOBAL_LEN)
+                        })
+                    }))
+                    .chain(core::iter::once((
+                        "builtins".to_string(),
+                        // SAFETY: This ID points to the `Thunk` that wraps this very
+                        // `AttrSet`. The index is calculated to be one position after
+                        // the `AttrSet` itself.
+                        unsafe { ExprId::from_raw(GLOBAL_LEN + SCOPED_LEN + 1) },
+                    )))
+                    .collect(),
+                ..AttrSet::default()
+            })))
+            .chain(core::iter::once(Lir::Thunk(
+                // SAFETY: This ID points to the `builtins` `AttrSet` defined just above.
+                // Its index is calculated to be at that exact position.
+                unsafe { ExprId::from_raw(GLOBAL_LEN + SCOPED_LEN) },
+            )))
+            .map(|lir| Box::new_in(lir, bump))
+            .collect_vec();
+        Self {
+            ir_count: lirs.len(),
+            hirs: Vec::new(),
+            lirs,
+            funcs: HashMap::new(),
+
+            global_scope: NonNull::from(bump.alloc(global_scope)),
+            repl_scope: NonNull::from(bump.alloc(HashMap::new())),
+            graph: DiGraphMap::new(),
+
+            primops,
+
+            bump,
+        }
+    }
+
+    pub fn downgrade_ctx<'a>(&'a mut self) -> DowngradeCtx<'a, 'bump> {
+        DowngradeCtx::new(self)
+    }
+
+    pub fn resolve_ctx<'a>(&'a mut self, root: ExprId) -> ResolveCtx<'a, 'bump> {
+        ResolveCtx::new(self, root)
+    }
+
+    pub fn eval_ctx<'a>(&'a mut self) -> EvalCtx<'a, 'bump> {
+        EvalCtx::new(self)
+    }
+    /// The main entry point for evaluating a Nix expression string.
+    ///
+    /// This function performs the following steps:
+    /// 1. Parses the expression string into an `rnix` AST.
+    /// 2. Downgrades the AST to the High-Level IR (HIR).
+    /// 3. Resolves the HIR to the Low-Level IR (LIR).
+    /// 4. Evaluates the LIR to produce a final `Value`.
+    pub fn eval(&mut self, expr: &str) -> Result<nixjit_value::Value> {
+        let root = rnix::Root::parse(expr);
+        if !root.errors().is_empty() {
+            return Err(Error::parse_error(
+                root.errors().iter().map(|err| err.to_string()).join("; "),
+            ));
+        }
+        let root = self
+            .downgrade_ctx()
+            .downgrade_root(root.tree().expr().unwrap())?;
+        let ctx = self.resolve_ctx(root);
+        ctx.resolve_root()?;
+        Ok(self.eval_ctx().eval(root)?.to_public())
+    }
+
+    pub fn add_binding(&mut self, ident: &str, expr: &str) -> Result<()> {
+        let root = rnix::Root::parse(expr);
+        let root_expr = root
+            .ok()
+            .map_err(|err| Error::parse_error(err.to_string()))?
+            .expr()
+            .unwrap();
+        let expr_id = self.downgrade_ctx().downgrade_root(root_expr)?;
+        self.resolve_ctx(expr_id).resolve_root()?;
+        // SAFETY: `repl_scope` is a `NonNull` pointer that is guaranteed to be valid
+        // for the lifetime of `Context`. It is initialized in `new()` and the memory
+        // it points to is managed by the `bump` arena. Therefore, it is safe to
+        // dereference it to a mutable reference here.
+        unsafe { self.repl_scope.as_mut() }.insert(ident.to_string(), expr_id);
+        Ok(())
+    }
+}
+
+impl Context<'_> {
+    fn alloc_id(&mut self) -> ExprId {
+        self.ir_count += 1;
+        // SAFETY: This function is the sole source of new `ExprId`s during the
+        // downgrade and resolve phases. By monotonically incrementing `ir_count`,
+        // we guarantee that each ID is unique and corresponds to a valid, soon-to-be-
+        // allocated slot in the IR vectors.
+        unsafe { ExprId::from_raw(self.ir_count - 1) }
+    }
+
+    fn add_dep(&mut self, from: ExprId, to: ExprId) {
+        self.graph.add_edge(from, to, ());
+    }
+}
+
+impl BuiltinsContext for Context<'_> {}

evaluator/nixjit_context/src/resolve.rs

@@ -0,0 +1,218 @@
+use std::{cell::RefCell, ptr::NonNull};
+
+use bumpalo::{boxed::Box, collections::Vec};
+use derive_more::{Constructor, Unwrap};
+use hashbrown::HashMap;
+use replace_with::replace_with_and_return;
+
+use nixjit_error::Result;
+use nixjit_hir::Hir;
+use nixjit_ir::{Const, ExprId, Param, StackIdx};
+use nixjit_lir::{Lir, LookupResult, Resolve, ResolveContext};
+
+use super::Context;
+
+#[derive(Clone)]
+enum Scope {
+    /// A `let` binding scope, mapping variable names to their expression IDs.
+    Let(HashMap<String, ExprId>),
+    /// A function argument scope. `Some` holds the name of the argument set if present.
+    Arg(Option<String>),
+    // Not using &'ctx HashMap<_, _> because bumpalo's Vec<'bump, T> is invariant over T.
+    Builtins(NonNull<HashMap<&'static str, ExprId>>),
+    Repl(NonNull<HashMap<String, ExprId>>),
+}
+
+/// Represents an expression at different stages of compilation.
+#[derive(Debug, Unwrap)]
+enum Ir {
+    /// An expression in the High-Level Intermediate Representation (HIR).
+    Hir(Hir),
+    /// An expression in the Low-Level Intermediate Representation (LIR).
+    Lir(Lir),
+}
+
+#[derive(Constructor)]
+struct Closure {
+    id: ExprId,
+    arg: ExprId,
+}
+
+pub struct ResolveCtx<'ctx, 'bump> {
+    ctx: &'ctx mut Context<'bump>,
+    irs: Vec<'bump, RefCell<Ir>>,
+    root: ExprId,
+    closures: Vec<'bump, Closure>,
+    scopes: Vec<'bump, Scope>,
+    has_with: bool,
+    with_used: bool,
+}
+
+impl<'ctx, 'bump> ResolveCtx<'ctx, 'bump> {
+    pub fn new(ctx: &'ctx mut Context<'bump>, root: ExprId) -> Self {
+        Self {
+            scopes: {
+                let mut vec = Vec::new_in(ctx.bump);
+                vec.push(Scope::Builtins(ctx.global_scope));
+                vec.push(Scope::Repl(ctx.repl_scope));
+                vec
+            },
+            has_with: false,
+            with_used: false,
+            irs: Vec::from_iter_in(
+                core::mem::take(&mut ctx.hirs)
+                    .into_iter()
+                    .map(Ir::Hir)
+                    .map(RefCell::new),
+                ctx.bump,
+            ),
+            closures: Vec::new_in(ctx.bump),
+            ctx,
+            root,
+        }
+    }
+
+    pub fn resolve_root(mut self) -> Result<()> {
+        let ret = self.resolve(self.root);
+        ret.map(|_| {
+            self.ctx.lirs.extend(
+                self.irs
+                    .into_iter()
+                    .map(RefCell::into_inner)
+                    .map(Ir::unwrap_lir)
+                    .map(|lir| Box::new_in(lir, self.ctx.bump)),
+            );
+        })
+    }
+
+    fn get_ir(&self, id: ExprId) -> &RefCell<Ir> {
+        let idx = unsafe { id.raw() } - self.ctx.lirs.len();
+        if cfg!(debug_assertions) {
+            self.irs.get(idx).unwrap()
+        } else {
+            unsafe { self.irs.get_unchecked(idx) }
+        }
+    }
+}
+
+impl ResolveContext for ResolveCtx<'_, '_> {
+    fn resolve(&mut self, expr: ExprId) -> Result<ExprId> {
+        unsafe {
+            let ctx = &mut *(self as *mut Self);
+            let ir = self.get_ir(expr);
+            if !matches!(ir.try_borrow().as_deref(), Ok(Ir::Hir(_))) {
+                return Ok(expr);
+            }
+            replace_with_and_return(
+                &mut *ir.borrow_mut(),
+                || {
+                    Ir::Hir(Hir::Const(Const {
+                        val: nixjit_value::Const::Null,
+                    }))
+                },
+                |ir| match ir.unwrap_hir().resolve(ctx) {
+                    Ok(lir @ Lir::ExprRef(expr)) => (Ok(expr), Ir::Lir(lir)),
+                    Ok(lir) => (Ok(expr), Ir::Lir(lir)),
+                    Err(err) => (
+                        Err(err),
+                        Ir::Hir(Hir::Const(Const {
+                            val: nixjit_value::Const::Null,
+                        })),
+                    ),
+                },
+            )
+        }
+    }
+
+    fn lookup(&mut self, name: &str) -> LookupResult {
+        let mut closure_depth = 0;
+        for scope in self.scopes.iter().rev() {
+            match scope {
+                Scope::Builtins(scope) => {
+                    if let Some(&primop) = unsafe { scope.as_ref() }.get(&name) {
+                        return LookupResult::Expr(primop);
+                    }
+                }
+                Scope::Let(scope) => {
+                    if let Some(&dep) = scope.get(name) {
+                        let expr = self
+                            .closures
+                            .last()
+                            .map_or_else(|| self.root, |closure| closure.id);
+                        self.ctx.add_dep(expr, dep);
+                        return LookupResult::Expr(dep);
+                    }
+                }
+                &Scope::Repl(scope) => {
+                    if let Some(&dep) = unsafe { scope.as_ref() }.get(name) {
+                        let expr = self
+                            .closures
+                            .last()
+                            .map_or_else(|| self.root, |closure| closure.id);
+                        self.ctx.add_dep(expr, dep);
+                        return LookupResult::Expr(dep);
+                    }
+                }
+                Scope::Arg(ident) => {
+                    if ident.as_deref() == Some(name) {
+                        let &Closure { id: func, arg } =
+                            self.closures.iter().nth_back(closure_depth).unwrap();
+                        self.ctx.add_dep(func, arg);
+                        return LookupResult::Expr(arg);
+                    }
+                    closure_depth += 1;
+                }
+            }
+        }
+        if self.has_with {
+            self.with_used = true;
+            LookupResult::Unknown
+        } else {
+            LookupResult::NotFound
+        }
+    }
+
+    fn lookup_arg(&mut self) -> ExprId {
+        self.closures.last().unwrap().arg
+    }
+
+    fn new_func(&mut self, body: ExprId, param: Param) {
+        self.ctx.funcs.insert(body, param);
+    }
+
+    fn with_let_env<T>(
+        &mut self,
+        bindings: HashMap<String, ExprId>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T {
+        self.scopes.push(Scope::Let(bindings));
+        let res = f(self);
+        self.scopes.pop();
+        res
+    }
+
+    fn with_with_env(&mut self, f: impl FnOnce(&mut Self) -> Result<()>) -> Result<bool> {
+        let has_with = self.has_with;
+        let with_used = self.with_used;
+        self.has_with = true;
+        self.with_used = false;
+        let res = f(self);
+        self.has_with = has_with;
+        res.map(|_| core::mem::replace(&mut self.with_used, with_used))
+    }
+
+    fn with_closure_env<T>(
+        &mut self,
+        func: ExprId,
+        arg: ExprId,
+        ident: Option<String>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T {
+        self.closures.push(Closure::new(func, arg));
+        self.scopes.push(Scope::Arg(ident));
+        let res = f(self);
+        self.scopes.pop();
+        self.closures.pop();
+        res
+    }
+}

evaluator/nixjit_error/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "nixjit_error"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+thiserror = "2.0"
+rnix = "0.12"

evaluator/nixjit_error/src/lib.rs

@@ -0,0 +1,159 @@
+//! This crate defines the centralized error types and `Result` alias used
+//! throughout the entire `nixjit` evaluation pipeline. By consolidating error
+//! handling here, we ensure a consistent approach to reporting failures across
+//! different stages of processing, from parsing to final evaluation.
+
+use std::rc::Rc;
+use thiserror::Error;
+
+/// A specialized `Result` type used for all fallible operations within the
+/// `nixjit` crates. It defaults to the crate's `Error` type.
+pub type Result<T> = core::result::Result<T, Error>;
+
+/// The primary error enum, encompassing all potential failures that can occur
+/// during the lifecycle of a Nix expression's evaluation.
+#[derive(Error, Debug)]
+pub enum ErrorKind {
+    /// An error occurred during the initial parsing phase. This typically
+    /// indicates a syntax error in the Nix source code, as detected by the
+    /// `rnix` parser.
+    #[error("error occurred during parse stage: {0}")]
+    ParseError(String),
+
+    /// An error occurred while "downgrading" the `rnix` AST to the
+    /// High-Level IR (HIR). This can happen if the AST has a structure that is
+    /// syntactically valid but semantically incorrect for our IR.
+    #[error("error occurred during downgrade stage: {0}")]
+    DowngradeError(String),
+
+    /// An error occurred during the variable resolution phase, where the HIR is
+    /// converted to the Low-Level IR (LIR). This is most commonly caused by
+    /// an unbound or undefined variable.
+    #[error("error occurred during variable resolve stage: {0}")]
+    ResolutionError(String),
+
+    /// An error occurred during the final evaluation of the LIR. This covers
+    /// all unrecoverable runtime errors, such as type mismatches (e.g., adding
+    /// a string to an integer), division by zero, or primitive operation
+    /// argument arity mismatch
+    #[error("error occurred during evaluation stage: {0}")]
+    EvalError(String),
+
+    /// Represents an error that can be generated by `throw` or `assert`, and
+    /// can be caught by `builtins.tryEval`.
+    #[error("{0}")]
+    Catchable(String),
+
+    /// A catch-all for any error that does not fit into the other categories.
+    #[error("an unknown or unexpected error occurred")]
+    Unknown,
+}
+
+#[derive(Debug)]
+pub struct Error {
+    pub kind: ErrorKind,
+    pub span: Option<rnix::TextRange>,
+    pub source: Option<Rc<str>>,
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        // Basic display
+        write!(f, "{}", self.kind)?;
+
+        // If we have source and span, print context
+        if let (Some(source), Some(span)) = (&self.source, self.span) {
+            let start_byte = usize::from(span.start());
+            let end_byte = usize::from(span.end());
+
+            if start_byte > source.len() || end_byte > source.len() {
+                return Ok(()); // Span is out of bounds
+            }
+
+            let mut start_line = 1;
+            let mut start_col = 1usize;
+            let mut line_start_byte = 0;
+            for (i, c) in source.char_indices() {
+                if i >= start_byte {
+                    break;
+                }
+                if c == '\n' {
+                    start_line += 1;
+                    start_col = 1;
+                    line_start_byte = i + 1;
+                } else {
+                    start_col += 1;
+                }
+            }
+
+            let line_end_byte = source[line_start_byte..]
+                .find('\n')
+                .map(|i| line_start_byte + i)
+                .unwrap_or(source.len());
+
+            let line_str = &source[line_start_byte..line_end_byte];
+
+            let underline_len = if end_byte > start_byte {
+                end_byte - start_byte
+            } else {
+                1
+            };
+
+            write!(f, "\n --> {}:{}", start_line, start_col)?;
+            write!(f, "\n  |\n")?;
+            writeln!(f, "{:4} | {}", start_line, line_str)?;
+            write!(
+                f,
+                "  | {}{}",
+                " ".repeat(start_col.saturating_sub(1)),
+                "^".repeat(underline_len)
+            )?;
+        }
+        Ok(())
+    }
+}
+
+impl std::error::Error for Error {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        Some(&self.kind)
+    }
+}
+
+impl Error {
+    pub fn new(kind: ErrorKind) -> Self {
+        Self {
+            kind,
+            span: None,
+            source: None,
+        }
+    }
+
+    pub fn with_span(mut self, span: rnix::TextRange) -> Self {
+        self.span = Some(span);
+        self
+    }
+
+    pub fn with_source(mut self, source: Rc<str>) -> Self {
+        self.source = Some(source);
+        self
+    }
+
+    pub fn parse_error(msg: String) -> Self {
+        Self::new(ErrorKind::ParseError(msg))
+    }
+    pub fn downgrade_error(msg: String) -> Self {
+        Self::new(ErrorKind::DowngradeError(msg))
+    }
+    pub fn resolution_error(msg: String) -> Self {
+        Self::new(ErrorKind::ResolutionError(msg))
+    }
+    pub fn eval_error(msg: String) -> Self {
+        Self::new(ErrorKind::EvalError(msg))
+    }
+    pub fn catchable(msg: String) -> Self {
+        Self::new(ErrorKind::Catchable(msg))
+    }
+    pub fn unknown() -> Self {
+        Self::new(ErrorKind::Unknown)
+    }
+}

evaluator/nixjit_eval/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "nixjit_eval"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+derive_more = { version = "2.0", features = ["full"] }
+hashbrown = "0.15"
+itertools = "0.14"
+replace_with = "0.1"
+smallvec = { version = "1.15", features = ["union"] }
+
+nixjit_error = { path = "../nixjit_error" }
+nixjit_ir = { path = "../nixjit_ir" }
+nixjit_lir = { path = "../nixjit_lir" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_eval/src/lib.rs

@@ -0,0 +1,349 @@
+//! This module defines the core traits and logic for evaluating the LIR.
+//!
+//! The central components are:
+//! - `EvalContext`: A trait that defines the environment and operations needed for evaluation.
+//!   It manages the evaluation stack, scopes, and primop calls.
+//! - `Evaluate`: A trait implemented by LIR nodes to define how they are evaluated.
+//! - `Value`: An enum representing all possible values during evaluation. This is an
+//!   internal representation, distinct from the public-facing `nixjit_value::Value`.
+
+use std::rc::Rc;
+
+use hashbrown::HashMap;
+
+use nixjit_error::{Error, Result};
+use nixjit_ir::{self as ir, ExprId, PrimOpId, SymId};
+use nixjit_lir as lir;
+use nixjit_value::format_symbol;
+
+pub use crate::value::*;
+
+mod value;
+
+/// A trait defining the context in which LIR expressions are evaluated.
+pub trait EvalContext {
+    fn eval(&mut self, id: ExprId) -> Result<Value>;
+
+    fn resolve(&mut self, id: ExprId) -> Result<ValueId>;
+
+    fn force(&mut self, id: ValueId) -> Result<Value>;
+
+    fn call(&mut self, func: ValueId, arg: Value) -> Result<Value>;
+
+    /// Enters a `with` scope for the duration of a closure's execution.
+    fn with_with_env<T>(
+        &mut self,
+        namespace: Rc<HashMap<String, Value>>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T;
+
+    /// Looks up an identifier in the current `with` scope chain.
+    fn lookup_with<'a>(&'a self, ident: SymId) -> Option<&'a Value>;
+
+    /// Calls a primitive operation (builtin) by its ID.
+    fn call_primop(&mut self, id: PrimOpId, args: Args) -> Result<Value>;
+
+    fn new_sym(&mut self, sym: String) -> SymId;
+    fn get_sym(&self, id: SymId) -> &str;
+}
+
+/// A trait for types that can be evaluated within an `EvalContext`.
+pub trait Evaluate<Ctx: EvalContext> {
+    /// Performs the evaluation.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value>;
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ExprId {
+    /// Evaluating an `ExprId` simply delegates to the context.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        ctx.eval(*self)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for lir::Lir {
+    /// Evaluates an LIR node by dispatching to the specific implementation for its variant.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        use lir::Lir::*;
+        match self {
+            AttrSet(x) => x.eval(ctx),
+            List(x) => x.eval(ctx),
+            HasAttr(x) => x.eval(ctx),
+            BinOp(x) => x.eval(ctx),
+            UnOp(x) => x.eval(ctx),
+            Select(x) => x.eval(ctx),
+            If(x) => x.eval(ctx),
+            Call(x) => x.eval(ctx),
+            With(x) => x.eval(ctx),
+            Assert(x) => x.eval(ctx),
+            ConcatStrings(x) => x.eval(ctx),
+            Const(x) => x.eval(ctx),
+            Str(x) => x.eval(ctx),
+            Var(x) => x.eval(ctx),
+            Path(x) => x.eval(ctx),
+            &ExprRef(expr) => ctx.eval(expr),
+            &FuncRef(body) => ctx.resolve(body).map(Value::Closure),
+            &Arg(_) => unreachable!(),
+            &PrimOp(primop) => Ok(Value::PrimOp(primop)),
+            &Thunk(id) => ctx.resolve(id).map(Value::Thunk),
+            &StackRef(idx) => todo!(),
+        }
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::AttrSet {
+    /// Evaluates an `AttrSet` by evaluating all its static and dynamic attributes.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let mut attrs = AttrSet::new(
+            self.stcs
+                .iter()
+                .map(|(&k, &v)| {
+                    let eval_result = v.eval(ctx);
+                    Ok((k, eval_result?))
+                })
+                .collect::<Result<_>>()?,
+        );
+        for (k, v) in self.dyns.iter() {
+            let v = v.eval(ctx)?;
+            let sym = k.eval(ctx)?.force_string_no_ctx()?;
+            let sym = ctx.new_sym(sym);
+            attrs.push_attr(sym, v, ctx)?;
+        }
+        let result = Value::AttrSet(attrs.into());
+        Ok(result)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::List {
+    /// Evaluates a `List` by evaluating all its items.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let items = self
+            .items
+            .iter()
+            .map(|val| val.eval(ctx))
+            .collect::<Result<Vec<_>>>()?;
+        let result = Value::List(List::from(items).into());
+        Ok(result)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::HasAttr {
+    /// Evaluates a `HasAttr` by evaluating the LHS and the attribute path, then performing the check.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        use ir::Attr::*;
+        let mut val = self.lhs.eval(ctx)?;
+        val.has_attr(self.rhs.iter().map(|attr| {
+            match attr {
+                &Str(ident) => Ok(ident),
+                Dynamic(expr) => expr
+                    .eval(ctx)?
+                    .force_string_no_ctx()
+                    .map(|sym| ctx.new_sym(sym)),
+            }
+        }))?;
+        Ok(val)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::BinOp {
+    /// Evaluates a `BinOp` by evaluating the LHS and RHS, then performing the operation.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        use ir::BinOpKind::*;
+        let mut lhs = self.lhs.eval(ctx)?;
+        if matches!((&self.kind, &lhs), (And, Value::Bool(false))) {
+            return Ok(Value::Bool(false));
+        } else if matches!((&self.kind, &lhs), (Or, Value::Bool(true))) {
+            return Ok(Value::Bool(true));
+        }
+        let mut rhs = self.rhs.eval(ctx)?;
+        match self.kind {
+            Add => lhs.add(rhs)?,
+            Sub => {
+                rhs.neg()?;
+                lhs.add(rhs)?;
+            }
+            Mul => lhs.mul(rhs)?,
+            Div => lhs.div(rhs)?,
+            Eq => lhs.eq(rhs),
+            Neq => {
+                lhs.eq(rhs);
+                let _ = lhs.not();
+            }
+            Lt => lhs.lt(rhs)?,
+            Gt => {
+                rhs.lt(lhs)?;
+                lhs = rhs;
+            }
+            Leq => {
+                rhs.lt(lhs)?;
+                let _ = rhs.not();
+                lhs = rhs;
+            }
+            Geq => {
+                lhs.lt(rhs)?;
+                let _ = lhs.not();
+            }
+            And => lhs.and(rhs)?,
+            Or => lhs.or(rhs)?,
+            Impl => {
+                lhs.not()?;
+                lhs.or(rhs)?;
+            }
+            Con => lhs.concat(rhs)?,
+            Upd => lhs.update(rhs)?,
+            PipeL => lhs.call(rhs, ctx)?,
+            PipeR => {
+                rhs.call(lhs, ctx)?;
+                lhs = rhs;
+            }
+        }
+        Ok(lhs)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::UnOp {
+    /// Evaluates a `UnOp` by evaluating the RHS and performing the operation.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        use ir::UnOpKind::*;
+        let mut rhs = self.rhs.eval(ctx)?;
+        match self.kind {
+            Neg => {
+                rhs.neg()?;
+            }
+            Not => {
+                rhs.not()?;
+            }
+        };
+        Ok(rhs)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Select {
+    /// Evaluates a `Select` by evaluating the expression, the path, and the default value (if any),
+    /// then performing the selection.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        use ir::Attr::*;
+        let mut val = self.expr.eval(ctx)?;
+        for attr in self.attrpath.iter() {
+            let name = match attr {
+                &Str(name) => name,
+                Dynamic(expr) => {
+                    let sym = expr.eval(ctx)?.force_string_no_ctx()?;
+                    ctx.new_sym(sym)
+                }
+            };
+            if let Some(default) = self.default {
+                val.select_or(name, default, ctx)
+            } else {
+                val.select(name, ctx)
+            }?
+        }
+        Ok(val)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::If {
+    /// Evaluates an `If` by evaluating the condition and then either the consequence or the alternative.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let cond = &self.cond.eval(ctx)?;
+        let &cond = cond.try_into().map_err(|_| {
+            Error::eval_error(format!(
+                "if-condition must be a boolean, but got {}",
+                cond.typename()
+            ))
+        })?;
+
+        if cond {
+            self.consq.eval(ctx)
+        } else {
+            self.alter.eval(ctx)
+        }
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Call {
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let mut func = self.func.eval(ctx)?;
+        func.call(self.arg.eval(ctx)?, ctx)?;
+        Ok(func)
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::With {
+    /// Evaluates a `With` by evaluating the namespace, entering a `with` scope,
+    /// and then evaluating the body.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let namespace = self.namespace.eval(ctx)?;
+        let typename = namespace.typename();
+        ctx.with_with_env(
+            namespace
+                .try_unwrap_attr_set()
+                .map_err(|_| {
+                    Error::eval_error(format!("'with' expects a set, but got {}", typename))
+                })?
+                .into_inner(),
+            |ctx| self.expr.eval(ctx),
+        )
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Assert {
+    /// Evaluates an `Assert` by evaluating the condition. If true, it evaluates and
+    /// returns the body; otherwise, it returns an error.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let cond = &self.assertion.eval(ctx)?;
+        let &cond = cond.try_into().map_err(|_| {
+            Error::eval_error(format!(
+                "assertion condition must be a boolean, but got {}",
+                cond.typename()
+            ))
+        })?;
+        if cond {
+            self.expr.eval(ctx)
+        } else {
+            Err(Error::catchable("assertion failed".into()))
+        }
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::ConcatStrings {
+    /// Evaluates a `ConcatStrings` by evaluating each part, coercing it to a string,
+    /// and then concatenating the results.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        let mut buf = String::new();
+        for part in self.parts.iter() {
+            buf.push_str(&part.eval(ctx)?.force_string_no_ctx()?);
+        }
+        Ok(Value::String(buf))
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Str {
+    /// Evaluates a `Str` literal into a `Value::String`.
+    fn eval(&self, _: &mut Ctx) -> Result<Value> {
+        Ok(Value::String(self.val.clone()))
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Const {
+    /// Evaluates a `Const` literal into its corresponding `Value` variant.
+    fn eval(&self, _: &mut Ctx) -> Result<Value> {
+        Ok(self.val.into())
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Var {
+    /// Evaluates a `Var` by looking it up in the `with` scope chain.
+    /// This is for variables that could not be resolved statically.
+    fn eval(&self, ctx: &mut Ctx) -> Result<Value> {
+        ctx.lookup_with(self.sym).cloned().ok_or_else(|| {
+            Error::eval_error(format!("undefined variable '{}'", format_symbol(ctx.get_sym(self.sym))))
+        })
+    }
+}
+
+impl<Ctx: EvalContext> Evaluate<Ctx> for ir::Path {
+    /// Evaluates a `Path`. (Currently a TODO).
+    fn eval(&self, _ctx: &mut Ctx) -> Result<Value> {
+        todo!()
+    }
+}

evaluator/nixjit_eval/src/value/attrset.rs

@@ -0,0 +1,176 @@
+//! Defines the runtime representation of an attribute set (a map).
+
+use core::ops::Deref;
+use std::fmt::Debug;
+use std::rc::Rc;
+
+use derive_more::Constructor;
+use hashbrown::HashMap;
+use hashbrown::hash_map::Entry;
+use itertools::Itertools;
+
+use nixjit_error::{Error, Result};
+use nixjit_ir::{ExprId, SymId};
+use nixjit_value::{self as p, format_symbol};
+
+use crate::EvalContext;
+
+use super::Value;
+
+/// A wrapper around a `HashMap` representing a Nix attribute set.
+///
+/// It uses `#[repr(transparent)]` to ensure it has the same memory layout
+/// as `HashMap<String, Value>`.
+#[repr(transparent)]
+#[derive(Clone, Constructor)]
+pub struct AttrSet {
+    data: HashMap<SymId, Value>,
+}
+
+impl Debug for AttrSet {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use Value::*;
+        write!(f, "{{ ")?;
+        for (k, v) in self.data.iter() {
+            match v {
+                List(_) => write!(f, "{:?} = [ ... ]; ", k)?,
+                AttrSet(_) => write!(f, "{:?} = {{ ... }}; ", k)?,
+                v => write!(f, "{:?} = {v:?}; ", k)?,
+            }
+        }
+        write!(f, "}}")
+    }
+}
+
+impl From<HashMap<SymId, Value>> for AttrSet {
+    fn from(data: HashMap<SymId, Value>) -> Self {
+        Self { data }
+    }
+}
+
+impl Deref for AttrSet {
+    type Target = HashMap<SymId, Value>;
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl AttrSet {
+    /// Creates a new `AttrSet` with a specified initial capacity.
+    pub fn with_capacity(cap: usize) -> Self {
+        AttrSet {
+            data: HashMap::with_capacity(cap),
+        }
+    }
+
+    /// Inserts an attribute, overwriting any existing attribute with the same name.
+    pub fn push_attr_force(&mut self, sym: SymId, val: Value) {
+        self.data.insert(sym, val);
+    }
+
+    /// Inserts an attribute, returns an error if the attribute is already defined.
+    pub fn push_attr(&mut self, sym: SymId, val: Value, ctx: &mut impl EvalContext) -> Result<()> {
+        match self.data.entry(sym) {
+            Entry::Occupied(occupied) => Err(Error::eval_error(format!(
+                "attribute '{}' already defined",
+                format_symbol(ctx.get_sym(*occupied.key()))
+            ))),
+            Entry::Vacant(vacant) => {
+                vacant.insert(val);
+                Ok(())
+            }
+        }
+    }
+
+    pub fn select(&self, name: SymId, ctx: &mut impl EvalContext) -> Result<Value> {
+        self.data
+            .get(&name)
+            .cloned()
+            .map(|attr| match attr {
+                Value::Thunk(id) => ctx.force(id),
+                val => Ok(val),
+            })
+            .ok_or_else(|| {
+                Error::eval_error(format!("attribute '{}' not found", format_symbol(ctx.get_sym(name))))
+            })?
+    }
+
+    pub fn select_or(
+        &self,
+        name: SymId,
+        default: ExprId,
+        ctx: &mut impl EvalContext,
+    ) -> Result<Value> {
+        self.data
+            .get(&name)
+            .map(|attr| match attr {
+                &Value::Thunk(id) => ctx.force(id),
+                val => Ok(val.clone()),
+            })
+            .unwrap_or_else(|| ctx.eval(default))
+    }
+
+    /// Checks if an attribute path exists within the set.
+    pub fn has_attr(
+        &self,
+        mut path: impl DoubleEndedIterator<Item = Result<SymId>>,
+    ) -> Result<Value> {
+        let mut data = &self.data;
+        let last = path.nth_back(0).unwrap();
+        for item in path {
+            let Some(Value::AttrSet(attrs)) = data.get(&item?)
+            else {
+                return Ok(Value::Bool(false));
+            };
+            data = attrs.as_inner();
+        }
+        Ok(Value::Bool(
+            data.get(&last?).is_some(),
+        ))
+    }
+
+    /// Merges another `AttrSet` into this one, with attributes from `other`
+    /// overwriting existing ones. This corresponds to the `//` operator in Nix.
+    pub fn update(&mut self, other: &Self) {
+        for (k, v) in other.data.iter() {
+            self.push_attr_force(k.clone(), v.clone())
+        }
+    }
+
+    /// Returns a reference to the inner `HashMap`.
+    pub fn as_inner(&self) -> &HashMap<SymId, Value> {
+        &self.data
+    }
+
+    /// Converts an `Rc<AttrSet>` to an `Rc<HashMap<String, Value>>` without allocation.
+    pub fn into_inner(self: Rc<Self>) -> Rc<HashMap<String, Value>> {
+        // SAFETY: This is safe because `AttrSet` is `#[repr(transparent)]` over
+        // `HashMap<String, Value>`, so `Rc<Self>` has the same layout as
+        // `Rc<HashMap<String, Value>>`.
+        unsafe { core::mem::transmute(self) }
+    }
+
+    /// Performs a deep equality comparison between two `AttrSet`s.
+    ///
+    /// It recursively compares the contents of both sets, ensuring that both keys
+    /// and values are identical. The attributes are sorted before comparison to
+    /// ensure a consistent result.
+    pub fn eq_impl(&self, other: &Self) -> bool {
+        self.data.iter().len() == other.data.iter().len()
+            && std::iter::zip(
+                self.data.iter().sorted_by(|(a, _), (b, _)| a.cmp(b)),
+                other.data.iter().sorted_by(|(a, _), (b, _)| a.cmp(b)),
+            )
+            .all(|((k1, v1), (k2, v2))| k1 == k2 && v1.eq_impl(v2))
+    }
+
+    /// Converts the `AttrSet` to its public-facing representation.
+    pub fn to_public(self, ctx: &mut impl EvalContext) -> p::Value {
+        p::Value::AttrSet(p::AttrSet::new(
+            self.data
+                .into_iter()
+                .map(|(sym, value)| (ctx.get_sym(sym).into(), value.to_public(ctx)))
+                .collect(),
+        ))
+    }
+}

evaluator/nixjit_eval/src/value/list.rs

@@ -0,0 +1,104 @@
+//! Defines the runtime representation of a list.
+
+use std::fmt::Debug;
+use std::ops::Deref;
+
+use nixjit_error::{Error, Result};
+use nixjit_value::List as PubList;
+use nixjit_value::Value as PubValue;
+
+use crate::EvalContext;
+
+use super::Value;
+
+/// A wrapper around a `Vec<Value>` representing a Nix list.
+#[derive(Clone, Default)]
+pub struct List {
+    data: Vec<Value>,
+}
+
+impl Debug for List {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[ ")?;
+        for v in self.data.iter() {
+            write!(f, "{v:?} ")?;
+        }
+        write!(f, "]")
+    }
+}
+
+impl<T: Into<Vec<Value>>> From<T> for List {
+    fn from(value: T) -> Self {
+        Self { data: value.into() }
+    }
+}
+
+impl Deref for List {
+    type Target = [Value];
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl List {
+    /// Creates a new, empty `List`.
+    pub fn new() -> Self {
+        List { data: Vec::new() }
+    }
+
+    /// Creates a new `List` with a specified initial capacity.
+    pub fn with_capacity(cap: usize) -> Self {
+        List {
+            data: Vec::with_capacity(cap),
+        }
+    }
+
+    /// Appends an element to the back of the list.
+    pub fn push(&mut self, elem: Value) {
+        self.data.push(elem);
+    }
+
+    /// Appends all elements from another `List` to this one.
+    /// This corresponds to the `++` operator in Nix.
+    pub fn concat(&mut self, other: &Self) {
+        for elem in other.data.iter() {
+            self.data.push(elem.clone());
+        }
+    }
+
+    pub fn elem_at(&self, idx: usize, ctx: &mut impl EvalContext) -> Result<Value> {
+        self.data
+            .get(idx)
+            .map(|elem| match elem {
+                &Value::Thunk(id) => ctx.force(id),
+                val => Ok(val.clone()),
+            })
+            .ok_or_else(|| {
+                Error::eval_error(format!(
+                    "'builtins.elemAt' called with index {idx} on a list of size {}",
+                    self.len()
+                ))
+            })?
+    }
+
+    /// Consumes the `List` and returns the inner `Vec<Value>`.
+    pub fn into_inner(self) -> Vec<Value> {
+        self.data
+    }
+
+    /// Performs a deep equality comparison between two `List`s.
+    pub fn eq_impl(&self, other: &Self) -> bool {
+        self.len() == other.len()
+            && core::iter::zip(self.iter(), other.iter()).all(|(a, b)| a.eq_impl(b))
+    }
+
+    /// Converts the `List` to its public-facing representation.
+    pub fn to_public(&self, ctx: &mut impl EvalContext) -> PubValue {
+        PubValue::List(PubList::new(
+            self.data
+                .iter()
+                .map(|value| value.clone().to_public(ctx))
+                .collect(),
+        ))
+    }
+}

evaluator/nixjit_eval/src/value/mod.rs

@@ -0,0 +1,456 @@
+//! Defines the internal representation of values during evaluation.
+//!
+//! This module introduces the `Value` enum, which is the cornerstone of the
+//! interpreter's runtime. It represents all possible data types that can exist
+//! during the evaluation of a Nix expression. This is an internal, mutable
+//! representation, distinct from the public-facing `nixjit_value::Value`.
+
+use std::fmt::Debug;
+use std::rc::Rc;
+
+use derive_more::{IsVariant, TryInto, TryUnwrap, Unwrap};
+use nixjit_ir::ExprId;
+use nixjit_ir::PrimOpId;
+
+use nixjit_error::{Error, Result};
+use nixjit_ir::SymId;
+use nixjit_value::Const;
+use nixjit_value::Value as PubValue;
+use replace_with::replace_with_and_return;
+use smallvec::smallvec;
+
+use crate::EvalContext;
+
+mod attrset;
+mod list;
+mod primop;
+mod string;
+
+pub use attrset::AttrSet;
+pub use list::List;
+pub use primop::*;
+
+/// The internal, C-compatible representation of a Nix value during evaluation.
+///
+/// This enum is designed for efficient manipulation within the interpreter and
+/// JIT-compiled code. It uses `#[repr(C, u64)]` to ensure a predictable layout,
+/// with the discriminant serving as a type tag.
+#[repr(C, u64)]
+#[derive(IsVariant, Clone, Unwrap, TryUnwrap, TryInto)]
+#[try_into(owned, ref, ref_mut)]
+pub enum Value {
+    Int(i64) = Self::INT,
+    Float(f64) = Self::FLOAT,
+    Bool(bool) = Self::BOOL,
+    String(String) = Self::STRING,
+    Null = Self::NULL,
+    Thunk(ValueId) = Self::THUNK,
+    AttrSet(Rc<AttrSet>) = Self::ATTRSET,
+    List(Rc<List>) = Self::LIST,
+    PrimOp(PrimOpId) = Self::PRIMOP,
+    PrimOpApp(Rc<PrimOpApp>) = Self::PRIMOP_APP,
+    Closure(ValueId) = Self::CLOSURE,
+}
+
+impl Debug for Value {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use Value::*;
+        match self {
+            Int(x) => write!(f, "{x}"),
+            Float(x) => write!(f, "{x}"),
+            Bool(x) => write!(f, "{x}"),
+            Null => write!(f, "null"),
+            String(x) => write!(f, "{x:?}"),
+            AttrSet(x) => write!(f, "{x:?}"),
+            List(x) => write!(f, "{x:?}"),
+            Thunk(thunk) => write!(f, "<THUNK {thunk:?}>"),
+            Closure(func) => write!(f, "<LAMBDA-APP {:?}>", func),
+            PrimOp(_) => write!(f, "<PRIMOP>"),
+            PrimOpApp(_) => write!(f, "<PRIMOP-APP>"),
+        }
+    }
+}
+
+impl From<Const> for Value {
+    fn from(value: nixjit_value::Const) -> Self {
+        match value {
+            Const::Null => Value::Null,
+            Const::Int(x) => Value::Int(x),
+            Const::Float(x) => Value::Float(x),
+            Const::Bool(x) => Value::Bool(x),
+        }
+    }
+}
+
+impl Value {
+    pub const INT: u64 = 0;
+    pub const FLOAT: u64 = 1;
+    pub const BOOL: u64 = 2;
+    pub const STRING: u64 = 3;
+    pub const NULL: u64 = 4;
+    pub const THUNK: u64 = 5;
+    pub const CLOSURE_THUNK: u64 = 6;
+    pub const ATTRSET: u64 = 7;
+    pub const LIST: u64 = 8;
+    pub const PRIMOP: u64 = 9;
+    pub const PRIMOP_APP: u64 = 10;
+    pub const CLOSURE: u64 = 11;
+
+    fn eq_impl(&self, other: &Self) -> bool {
+        use Value::*;
+        match (self, other) {
+            (Bool(a), Bool(b)) => a == b,
+            (Int(a), Int(b)) => a == b,
+            (Float(a), Float(b)) => a == b,
+            (Int(a), Float(b)) => *a as f64 == *b,
+            (Float(a), Int(b)) => *b as f64 == *a,
+            (String(a), String(b)) => a.as_str().eq(b.as_str()),
+            (Null, Null) => true,
+            (AttrSet(a), AttrSet(b)) => a.eq_impl(b),
+            (List(a), List(b)) => a.eq_impl(b),
+            _ => false,
+        }
+    }
+}
+
+impl Value {
+    /// Returns the name of the value's type.
+    pub fn typename(&self) -> &'static str {
+        use Value::*;
+        match self {
+            Int(_) => "int",
+            Float(_) => "float",
+            Bool(_) => "bool",
+            String(_) => "string",
+            Null => "null",
+            Thunk(_) => "thunk",
+            AttrSet(_) => "set",
+            List(_) => "list",
+            PrimOp(_) => "lambda",
+            PrimOpApp(_) => "lambda",
+            Closure(..) => "lambda",
+        }
+    }
+
+    pub fn force(&mut self, ctx: &mut impl EvalContext) -> Result<()> {
+        let map = |result| match result {
+            Ok(ok) => (Ok(()), ok),
+            Err(err) => (Err(err), Value::Null),
+        };
+        replace_with_and_return(
+            self,
+            || Value::Null,
+            |val| match val {
+                Value::Thunk(id) => map(ctx.force(id)),
+                val => (Ok(()), val),
+            },
+        )
+    }
+
+    /// Performs a function call on the `Value`.
+    ///
+    /// This method handles calling functions, primops, and their partially
+    /// applied variants. It manages argument application and delegates to the
+    /// `EvalContext` for the actual execution.
+    pub fn call<Ctx: EvalContext>(&mut self, arg: Value, ctx: &mut Ctx) -> Result<()> {
+        use Value::*;
+        let map = |result| match result {
+            Ok(ok) => (Ok(()), ok),
+            Err(err) => (Err(err), Null),
+        };
+        replace_with_and_return(
+            self,
+            || Null,
+            |func| match func {
+                PrimOp(id) => map(ctx.call_primop(id, smallvec![arg])),
+                PrimOpApp(primop) => map(primop.call(arg, ctx)),
+                Closure(func) => map(ctx.call(func, arg)),
+                _ => (
+                    Err(Error::eval_error(
+                        "attempt to call something which is not a function but ...".to_string(),
+                    )),
+                    Null,
+                ),
+            },
+        )
+    }
+
+    pub fn not(&mut self) -> Result<()> {
+        use Value::*;
+        match &*self {
+            Bool(bool) => {
+                *self = Bool(!bool);
+                Ok(())
+            }
+            _ => Err(Error::eval_error(format!(
+                "expected a boolean but found {}",
+                self.typename()
+            ))),
+        }
+    }
+
+    pub fn and(&mut self, other: Self) -> Result<()> {
+        use Value::*;
+        match (&*self, other) {
+            (&Bool(a), Bool(b)) => {
+                *self = Bool(a && b);
+                Ok(())
+            }
+            _ => Err(Error::eval_error(format!(
+                "expected a boolean but found {}",
+                self.typename()
+            ))),
+        }
+    }
+
+    pub fn or(&mut self, other: Self) -> Result<()> {
+        use Value::*;
+        match (&*self, other) {
+            (&Bool(a), Bool(b)) => {
+                *self = Bool(a || b);
+                Ok(())
+            }
+            _ => Err(Error::eval_error(format!(
+                "expected a boolean but found {}",
+                self.typename()
+            ))),
+        }
+    }
+
+    pub fn eq(&mut self, other: Self) {
+        *self = Value::Bool(self.eq_impl(&other));
+    }
+
+    pub fn lt(&mut self, other: Self) -> Result<()> {
+        use Value::*;
+        *self = Bool(match (&*self, other) {
+            (Int(a), Int(b)) => *a < b,
+            (Int(a), Float(b)) => (*a as f64) < b,
+            (Float(a), Int(b)) => *a < b as f64,
+            (Float(a), Float(b)) => *a < b,
+            (String(a), String(b)) => a.as_str() < b.as_str(),
+            (a, b) => {
+                return Err(Error::eval_error(format!(
+                    "cannot compare {} with {}",
+                    a.typename(),
+                    b.typename()
+                )));
+            }
+        });
+        Ok(())
+    }
+
+    pub fn neg(&mut self) -> Result<()> {
+        use Value::*;
+        *self = match &*self {
+            Int(int) => Int(-int),
+            Float(float) => Float(-float),
+            _ => {
+                return Err(Error::eval_error(format!(
+                    "expected an integer but found {}",
+                    self.typename()
+                )));
+            }
+        };
+        Ok(())
+    }
+
+    pub fn add(mut self: &mut Self, other: Self) -> Result<()> {
+        use Value::*;
+        if let (String(a), String(b)) = (&mut self, &other) {
+            a.push_str(b.as_str());
+            return Ok(());
+        }
+        *self = match (&mut self, other) {
+            (Int(a), Int(b)) => Int(*a + b),
+            (&mut Int(a), Float(b)) => Float(*a as f64 + b),
+            (&mut Float(a), Int(b)) => Float(*a + b as f64),
+            (&mut Float(a), Float(b)) => Float(*a + b),
+            (a, b) => {
+                return Err(Error::eval_error(format!(
+                    "cannot add {} to {}",
+                    a.typename(),
+                    b.typename()
+                )));
+            }
+        };
+        Ok(())
+    }
+
+    pub fn mul(&mut self, other: Self) -> Result<()> {
+        use Value::*;
+        *self = match (&*self, other) {
+            (Int(a), Int(b)) => Int(a * b),
+            (Int(a), Float(b)) => Float(*a as f64 * b),
+            (Float(a), Int(b)) => Float(a * b as f64),
+            (Float(a), Float(b)) => Float(a * b),
+            (a, b) => {
+                return Err(Error::eval_error(format!(
+                    "cannot multiply {} with {}",
+                    a.typename(),
+                    b.typename()
+                )));
+            }
+        };
+        Ok(())
+    }
+
+    pub fn div(&mut self, other: Self) -> Result<()> {
+        use Value::*;
+        *self = match (&*self, other) {
+            (_, Int(0)) => return Err(Error::eval_error("division by zero".to_string())),
+            (_, Float(0.)) => {
+                return Err(Error::eval_error("division by zero".to_string()));
+            }
+            (Int(a), Int(b)) => Int(a / b),
+            (Int(a), Float(b)) => Float(*a as f64 / b),
+            (Float(a), Int(b)) => Float(a / b as f64),
+            (Float(a), Float(b)) => Float(a / b),
+            (a, b) => {
+                return Err(Error::eval_error(format!(
+                    "cannot divide {} with {}",
+                    a.typename(),
+                    b.typename()
+                )));
+            }
+        };
+        Ok(())
+    }
+
+    pub fn concat(mut self: &mut Self, other: Self) -> Result<()> {
+        use Value::*;
+        match (&mut self, other) {
+            (List(a), List(b)) => {
+                Rc::make_mut(a).concat(&b);
+                Ok(())
+            }
+            (List(_), b) => Err(Error::eval_error(format!(
+                "expected a list but found {}",
+                b.typename()
+            ))),
+            (a, _) => Err(Error::eval_error(format!(
+                "expected a list but found {}",
+                a.typename()
+            ))),
+        }
+    }
+
+    pub fn update(mut self: &mut Self, other: Self) -> Result<()> {
+        use Value::*;
+        match (&mut self, other) {
+            (AttrSet(a), AttrSet(b)) => {
+                Rc::make_mut(a).update(&b);
+                Ok(())
+            }
+            (AttrSet(_), other) => Err(Error::eval_error(format!(
+                "expected a set but found {}",
+                other.typename()
+            ))),
+            _ => Err(Error::eval_error(format!(
+                "expected a set but found {}",
+                self.typename()
+            ))),
+        }
+    }
+
+    pub fn select(&mut self, name: SymId, ctx: &mut impl EvalContext) -> Result<()> {
+        use Value::*;
+        let val = match self {
+            AttrSet(attrs) => attrs.select(name, ctx),
+            _ => Err(Error::eval_error(format!(
+                "expected a set but found {}",
+                self.typename()
+            ))),
+        }?;
+        *self = val;
+        Ok(())
+    }
+
+    pub fn select_or<Ctx: EvalContext>(
+        &mut self,
+        name: SymId,
+        default: ExprId,
+        ctx: &mut Ctx,
+    ) -> Result<()> {
+        use Value::*;
+        let val = match self {
+            AttrSet(attrs) => attrs.select_or(name, default, ctx)?,
+            _ => {
+                return Err(Error::eval_error(format!(
+                    "expected a set but found {}",
+                    self.typename()
+                )));
+            }
+        };
+        *self = val;
+        Ok(())
+    }
+
+    pub fn has_attr(&mut self, path: impl DoubleEndedIterator<Item = Result<SymId>>) -> Result<()> {
+        use Value::*;
+        if let AttrSet(attrs) = self {
+            let val = attrs.has_attr(path)?;
+            *self = val;
+        } else {
+            *self = Bool(false);
+        }
+        Ok(())
+    }
+
+    pub fn force_string_no_ctx(self) -> Result<String> {
+        use Value::*;
+        if let String(string) = self {
+            Ok(string)
+        } else {
+            Err(Error::eval_error(format!(
+                "cannot coerce {} to string",
+                self.typename()
+            )))
+        }
+    }
+
+    /// Converts the internal `Value` to its public-facing, serializable
+    /// representation from the `nixjit_value` crate.
+    pub fn to_public(self, ctx: &mut impl EvalContext) -> PubValue {
+        use Value::*;
+        match self {
+            AttrSet(attrs) => Rc::unwrap_or_clone(attrs).to_public(ctx),
+            List(list) => Rc::unwrap_or_clone(list.clone()).to_public(ctx),
+            Int(x) => PubValue::Const(Const::Int(x)),
+            Float(x) => PubValue::Const(Const::Float(x)),
+            Bool(x) => PubValue::Const(Const::Bool(x)),
+            String(x) => PubValue::String(x),
+            Null => PubValue::Const(Const::Null),
+            Thunk(_) => PubValue::Thunk,
+            PrimOp(_) => PubValue::PrimOp,
+            PrimOpApp(_) => PubValue::PrimOpApp,
+            Closure(..) => PubValue::Func,
+        }
+    }
+}
+
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
+pub struct ValueId(usize);
+
+impl ValueId {
+    /// Returns the raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible for using this index correctly and not causing out-of-bounds access.
+    #[inline(always)]
+    pub unsafe fn raw(self) -> usize {
+        self.0
+    }
+
+    /// Creates an `ExprId` from a raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that the provided index is valid for the expression table.
+    #[inline(always)]
+    pub unsafe fn from_raw(id: usize) -> Self {
+        Self(id)
+    }
+}

evaluator/nixjit_eval/src/value/primop.rs

@@ -0,0 +1,33 @@
+//! Defines the runtime representation of a partially applied primitive operation.
+
+use std::rc::Rc;
+
+use derive_more::Constructor;
+
+use nixjit_error::Result;
+use nixjit_ir::PrimOpId;
+
+use super::Value;
+use crate::EvalContext;
+
+pub type Args = smallvec::SmallVec<[Value; 2]>;
+
+/// Represents a partially applied primitive operation (builtin function).
+///
+/// This struct holds the state of a primop that has received some, but not
+/// all, of its required arguments.
+#[derive(Debug, Clone, Constructor)]
+pub struct PrimOpApp {
+    /// The unique ID of the primop.
+    id: PrimOpId,
+    /// The arguments that have already been applied.
+    args: Args,
+}
+
+impl PrimOpApp {
+    pub fn call(self: Rc<Self>, arg: Value, ctx: &mut impl EvalContext) -> Result<Value> {
+        let PrimOpApp { id, mut args } = Rc::unwrap_or_clone(self);
+        args.push(arg);
+        ctx.call_primop(id, args)
+    }
+}

evaluator/nixjit_eval/src/value/string.rs

@@ -0,0 +1,38 @@
+//! Defines a placeholder for Nix's contextful strings.
+//!
+//! In Nix, strings can carry a "context" which affects how they are
+//! handled, particularly with regards to path resolution. This module
+//! provides the basic structures for this feature, although it is
+//! currently a work in progress.
+
+// TODO: Contextful String
+
+/// Represents the context associated with a string.
+pub struct StringContext {
+    context: Vec<()>,
+}
+
+impl StringContext {
+    /// Creates a new, empty `StringContext`.
+    pub fn new() -> StringContext {
+        StringContext {
+            context: Vec::new(),
+        }
+    }
+}
+
+/// A string that carries an associated context.
+pub struct ContextfulString {
+    string: String,
+    context: StringContext,
+}
+
+impl ContextfulString {
+    /// Creates a new `ContextfulString` from a standard `String`.
+    pub fn new(string: String) -> ContextfulString {
+        ContextfulString {
+            string,
+            context: StringContext::new(),
+        }
+    }
+}

evaluator/nixjit_hir/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "nixjit_hir"
+description = "The high-level intermediate representation (HIR) for nixjit."
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+derive_more = { version = "2.0", features = ["full"] }
+hashbrown = "0.15"
+rnix = "0.12"
+
+nixjit_error = { path = "../nixjit_error" }
+nixjit_ir = { path = "../nixjit_ir" }
+nixjit_macros = { path = "../nixjit_macros" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_hir/src/downgrade.rs

@@ -0,0 +1,363 @@
+//! This module handles the "downgrading" of the `rnix` Abstract Syntax Tree (AST)
+//! into the High-level Intermediate Representation (HIR). The term "downgrade" is used
+//! because the process moves from a concrete syntax tree, which is very detailed about
+//! source code structure (like parentheses and whitespace), to a more abstract,
+//! semantically-focused representation.
+//!
+//! The core of this module is the `Downgrade` trait, which defines a standard way to
+//! convert different AST node types into their corresponding HIR representations.
+
+use rnix::ast::{self, Expr};
+
+use nixjit_error::{Error, Result};
+
+use super::*;
+
+/// A trait for converting (downgrading) an `rnix` AST node into an HIR expression.
+pub trait Downgrade<Ctx: DowngradeContext> {
+    /// Performs the downgrade conversion.
+    ///
+    /// # Arguments
+    /// * `self` - The `rnix` AST node to convert.
+    /// * `ctx` - The context for the conversion, used for allocating new HIR expressions.
+    ///
+    /// # Returns
+    /// A `Result` containing the `ExprId` of the newly created HIR expression, or an error.
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId>;
+}
+
+/// The main entry point for downgrading any `rnix` expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for Expr {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        use Expr::*;
+        match self {
+            // Dispatch to the specific implementation for each expression type.
+            Apply(apply) => apply.downgrade(ctx),
+            Assert(assert) => assert.downgrade(ctx),
+            Error(error) => Err(self::Error::downgrade_error(error.to_string())),
+            IfElse(ifelse) => ifelse.downgrade(ctx),
+            Select(select) => select.downgrade(ctx),
+            Str(str) => str.downgrade(ctx),
+            Path(path) => path.downgrade(ctx),
+            Literal(lit) => lit.downgrade(ctx),
+            Lambda(lambda) => lambda.downgrade(ctx),
+            LegacyLet(let_) => let_.downgrade(ctx),
+            LetIn(letin) => letin.downgrade(ctx),
+            List(list) => list.downgrade(ctx),
+            BinOp(op) => op.downgrade(ctx),
+            AttrSet(attrs) => attrs.downgrade(ctx),
+            UnaryOp(op) => op.downgrade(ctx),
+            Ident(ident) => ident.downgrade(ctx),
+            With(with) => with.downgrade(ctx),
+            HasAttr(has) => has.downgrade(ctx),
+            // Parentheses and the root node are transparent; we just downgrade their contents.
+            Paren(paren) => paren.expr().unwrap().downgrade(ctx),
+            Root(root) => root.expr().unwrap().downgrade(ctx),
+        }
+    }
+}
+
+/// Downgrades an `assert` expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Assert {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let assertion = self.condition().unwrap().downgrade(ctx)?;
+        let expr = self.body().unwrap().downgrade(ctx)?;
+        Ok(ctx.new_expr(Assert { assertion, expr }.to_hir()))
+    }
+}
+
+/// Downgrades an `if-then-else` expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::IfElse {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let cond = self.condition().unwrap().downgrade(ctx)?;
+        let consq = self.body().unwrap().downgrade(ctx)?;
+        let alter = self.else_body().unwrap().downgrade(ctx)?;
+        Ok(ctx.new_expr(If { cond, consq, alter }.to_hir()))
+    }
+}
+
+/// Downgrades a path expression.
+/// A path can be a simple literal or contain interpolated expressions.
+/// If it contains interpolations, it's converted into a `ConcatStrings` HIR node
+/// which is then wrapped in a `Path` node.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Path {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let parts = self
+            .parts()
+            .map(|part| match part {
+                ast::InterpolPart::Literal(lit) => Ok(ctx.new_expr(
+                    Str {
+                        val: lit.to_string(),
+                    }
+                    .to_hir(),
+                )),
+                ast::InterpolPart::Interpolation(interpol) => {
+                    interpol.expr().unwrap().downgrade(ctx)
+                }
+            })
+            .collect::<Result<Vec<_>>>()?;
+        let expr = if parts.len() == 1 {
+            // If there's only one part, it's a simple string, no concatenation needed.
+            parts.into_iter().next().unwrap()
+        } else {
+            // Multiple parts (e.g., `./${name}.txt`) require string concatenation.
+            ctx.new_expr(ConcatStrings { parts }.to_hir())
+        };
+        Ok(ctx.new_expr(Path { expr }.to_hir()))
+    }
+}
+
+/// Downgrades a string expression.
+/// A string can be a simple literal or contain interpolated expressions.
+/// If it contains interpolations, it's converted into a `ConcatStrings` HIR node.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Str {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let parts = self
+            .normalized_parts()
+            .into_iter()
+            .map(|part| match part {
+                ast::InterpolPart::Literal(lit) => Ok(ctx.new_expr(Str { val: lit }.to_hir())),
+                ast::InterpolPart::Interpolation(interpol) => {
+                    interpol.expr().unwrap().downgrade(ctx)
+                }
+            })
+            .collect::<Result<Vec<_>>>()?;
+        Ok(if parts.len() == 1 {
+            // If there's only one part, it's a simple string, no concatenation needed.
+            parts.into_iter().next().unwrap()
+        } else {
+            // Multiple parts (e.g., "hello ${name}") require string concatenation.
+            ctx.new_expr(ConcatStrings { parts }.to_hir())
+        })
+    }
+}
+
+/// Downgrades a literal value (integer, float, or URI).
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Literal {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        Ok(ctx.new_expr(match self.kind() {
+            ast::LiteralKind::Integer(int) => Const::from(int.value().unwrap()).to_hir(),
+            ast::LiteralKind::Float(float) => Const::from(float.value().unwrap()).to_hir(),
+            ast::LiteralKind::Uri(uri) => Str {
+                val: uri.to_string(),
+            }
+            .to_hir(),
+        }))
+    }
+}
+
+/// Downgrades an identifier to a variable lookup.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Ident {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let sym = self.ident_token().unwrap().to_string();
+        let sym = ctx.new_sym(sym);
+        Ok(ctx.new_expr(Var { sym }.to_hir()))
+    }
+}
+
+/// Downgrades an attribute set.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::AttrSet {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let rec = self.rec_token().is_some();
+        let attrs = downgrade_attrs(self, ctx)?;
+        let bindings = attrs.stcs.clone();
+        let body = ctx.new_expr(attrs.to_hir());
+        if rec {
+            Ok(ctx.new_expr(Let { bindings, body }.to_hir()))
+        } else {
+            Ok(body)
+        }
+    }
+}
+
+/// Downgrades a list.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::List {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let items = self
+            .items()
+            .map(|item| maybe_thunk(item, ctx))
+            .collect::<Result<_>>()?;
+        Ok(ctx.new_expr(List { items }.to_hir()))
+    }
+}
+
+/// Downgrades a binary operation.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::BinOp {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let lhs = self.lhs().unwrap().downgrade(ctx)?;
+        let rhs = self.rhs().unwrap().downgrade(ctx)?;
+        let kind = self.operator().unwrap().into();
+        Ok(ctx.new_expr(BinOp { lhs, rhs, kind }.to_hir()))
+    }
+}
+
+/// Downgrades a "has attribute" (`?`) expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::HasAttr {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let lhs = self.expr().unwrap().downgrade(ctx)?;
+        let rhs = downgrade_attrpath(self.attrpath().unwrap(), ctx)?;
+        Ok(ctx.new_expr(HasAttr { lhs, rhs }.to_hir()))
+    }
+}
+
+/// Downgrades a unary operation.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::UnaryOp {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let rhs = self.expr().unwrap().downgrade(ctx)?;
+        let kind = self.operator().unwrap().into();
+        Ok(ctx.new_expr(UnOp { rhs, kind }.to_hir()))
+    }
+}
+
+/// Downgrades an attribute selection (`.`).
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Select {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let expr = self.expr().unwrap().downgrade(ctx)?;
+        let attrpath = downgrade_attrpath(self.attrpath().unwrap(), ctx)?;
+        let default = if let Some(default) = self.default_expr() {
+            Some(default.downgrade(ctx)?)
+        } else {
+            None
+        };
+        Ok(ctx.new_expr(
+            Select {
+                expr,
+                attrpath,
+                default,
+            }
+            .to_hir(),
+        ))
+    }
+}
+
+/// Downgrades a `legacy let`, which is essentially a recursive attribute set.
+/// The body of the `let` is accessed via `let.body`.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::LegacyLet {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let attrs = downgrade_attrs(self, ctx)?;
+        let bindings = attrs.stcs.clone();
+        let body = ctx.new_expr(attrs.to_hir());
+        let expr = ctx.new_expr(Let { bindings, body }.to_hir());
+        let sym = ctx.new_sym("body".into());
+        // The result of a `legacy let` is the `body` attribute of the resulting set.
+        let attrpath = vec![Attr::Str(sym)];
+        Ok(ctx.new_expr(
+            Select {
+                expr,
+                attrpath,
+                default: None,
+            }
+            .to_hir(),
+        ))
+    }
+}
+
+/// Downgrades a `let ... in ...` expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::LetIn {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let body = self.body().unwrap().downgrade(ctx)?;
+        let bindings = downgrade_static_attrs(self, ctx)?;
+        Ok(ctx.new_expr(Let { bindings, body }.to_hir()))
+    }
+}
+
+/// Downgrades a `with` expression.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::With {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let namespace = self.namespace().unwrap().downgrade(ctx)?;
+        let expr = self.body().unwrap().downgrade(ctx)?;
+        Ok(ctx.new_expr(With { namespace, expr }.to_hir()))
+    }
+}
+
+/// Downgrades a lambda (function) expression.
+/// This involves desugaring pattern-matching arguments into `let` bindings.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Lambda {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let param = downgrade_param(self.param().unwrap(), ctx)?;
+        let mut body = self.body().unwrap().downgrade(ctx)?;
+        let arg = ctx.new_expr(Hir::Arg(()));
+
+        let ident;
+        let required;
+        let allowed;
+        match param {
+            Param::Ident(id) => {
+                // Simple case: `x: body`
+                ident = Some(ctx.new_sym(id));
+                required = None;
+                allowed = None;
+            }
+            Param::Formals {
+                formals,
+                ellipsis,
+                alias,
+            } => {
+                // Complex case: `{ a, b ? 2, ... }@args: body`
+                let alias = alias.map(|sym| ctx.new_sym(sym));
+                ident = alias;
+                required = Some(
+                    formals
+                        .iter()
+                        .filter(|(_, default)| default.is_none())
+                        .map(|(k, _)| ctx.new_sym(k.clone()))
+                        .collect(),
+                );
+                allowed = if ellipsis {
+                    None // `...` means any attribute is allowed.
+                } else {
+                    Some(formals.iter().map(|(k, _)| ctx.new_sym(k.clone())).collect())
+                };
+
+                // Desugar pattern matching in function arguments into a `let` expression.
+                // For example, `({ a, b ? 2 }): a + b` is desugared into:
+                // `arg: let a = arg.a; b = arg.b or 2; in a + b`
+                let mut bindings: HashMap<_, _> = formals
+                    .into_iter()
+                    .map(|(k, default)| {
+                        // For each formal parameter, create a `Select` expression to extract it from the argument set.
+                        // `Arg` represents the raw argument (the attribute set) passed to the function.
+                        let k = ctx.new_sym(k);
+                        (
+                            k,
+                            ctx.new_expr(
+                                Select {
+                                    expr: arg,
+                                    attrpath: vec![Attr::Str(k)],
+                                    default,
+                                }
+                                .to_hir(),
+                            ),
+                        )
+                    })
+                    .collect();
+                // If there's an alias (`... }@alias`), bind the alias name to the raw argument set.
+                if let Some(alias) = alias {
+                    bindings.insert(alias, arg);
+                }
+                // Wrap the original function body in the new `let` expression.
+                let let_ = Let { bindings, body };
+                body = ctx.new_expr(let_.to_hir());
+            }
+        }
+
+        let param = IrParam {
+            ident,
+            required,
+            allowed,
+        };
+        // The function's body and parameters are now stored directly in the `Func` node.
+        Ok(ctx.new_expr(Func { body, param, arg }.to_hir()))
+    }
+}
+
+/// Downgrades a function application.
+/// In Nix, function application is left-associative, so `f a b` should be parsed as `((f a) b)`.
+/// Each Apply node represents a single function call with one argument.
+impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Apply {
+    fn downgrade(self, ctx: &mut Ctx) -> Result<ExprId> {
+        let func = self.lambda().unwrap().downgrade(ctx)?;
+        let arg = maybe_thunk(self.argument().unwrap(), ctx)?;
+        Ok(ctx.new_expr(Call { func, arg }.to_hir()))
+    }
+}

evaluator/nixjit_hir/src/lib.rs

@@ -0,0 +1,207 @@
+//! The high-level intermediate representation (HIR) for nixjit.
+//!
+//! This module defines the data structures for the HIR, which is a more abstract and
+//! semantically rich representation of the original Nix code compared to the raw AST from `rnix`.
+//! It's designed to be easily translatable from the AST and serves as a stepping stone
+//! towards the lower-level IR (`nixjit_lir`).
+//!
+//! The key components are:
+//! - `Hir`: An enum representing all possible expression types in the HIR. This is
+//!   generated by the `ir!` macro.
+//! - `Downgrade`: A trait for converting `rnix::ast` nodes into HIR expressions.
+//! - `DowngradeContext`: A trait that provides the necessary context for the conversion,
+//!   such as allocating new expressions.
+
+use derive_more::{IsVariant, TryUnwrap, Unwrap};
+use hashbrown::HashMap;
+
+use nixjit_error::{Error, Result};
+use nixjit_ir::{
+    Assert, Attr, AttrSet, BinOp, Call, ConcatStrings, Const, ExprId, Func, HasAttr, If, List, Param as IrParam, Path, Select, Str, SymId, UnOp, Var, With
+};
+use nixjit_macros::ir;
+use nixjit_value::format_symbol;
+
+mod downgrade;
+mod utils;
+use utils::*;
+
+pub use downgrade::Downgrade;
+
+/// A context for the AST-to-HIR downgrading process.
+///
+/// This trait abstracts the storage of HIR expressions, allowing the
+/// `downgrade` implementations to be generic over the specific context implementation.
+pub trait DowngradeContext {
+    /// Allocates a new HIR expression in the context and returns its ID.
+    fn new_expr(&mut self, expr: Hir) -> ExprId;
+
+    fn new_sym(&mut self, sym: String) -> SymId;
+
+    fn get_sym(&self, id: SymId) -> &str;
+
+    /// Provides temporary mutable access to an expression.
+    fn with_expr_mut<T>(&mut self, id: ExprId, f: impl FnOnce(&mut Hir, &mut Self) -> T) -> T;
+
+    fn downgrade_root(self, expr: rnix::ast::Expr) -> Result<ExprId>;
+}
+
+// The `ir!` macro generates the `Hir` enum and related structs and traits.
+// This reduces boilerplate for defining the IR structure.
+ir! {
+    Hir,
+
+    // Represents an attribute set, e.g., `{ a = 1; b = 2; }`.
+    AttrSet,
+    // Represents a list, e.g., `[1 2 3]`.
+    List,
+    // Represents a "has attribute" check, e.g., `attrs ? a`.
+    HasAttr,
+    // Represents a binary operation, e.g., `a + b`.
+    BinOp,
+    // Represents a unary operation, e.g., `-a`.
+    UnOp,
+    // Represents an attribute selection, e.g., `attrs.a` or `attrs.a or defaultValue`.
+    Select,
+    // Represents an if-then-else expression.
+    If,
+    // Represents a function definition (lambda).
+    Func,
+    // Represents a function call.
+    Call,
+    // Represents a `with` expression, e.g., `with pkgs; stdenv.mkDerivation { ... }`.
+    With,
+    // Represents an `assert` expression.
+    Assert,
+    // Represents the concatenation of strings, often from interpolated strings.
+    ConcatStrings,
+    // Represents a constant value (integer, float, boolean, null).
+    Const,
+    // Represents a simple string literal.
+    Str,
+    // Represents a variable lookup by its symbol/name.
+    Var,
+    // Represents a path expression.
+    Path,
+    // Represents a `let ... in ...` binding.
+    Let { pub bindings: HashMap<SymId, ExprId>, pub body: ExprId },
+    // Represents a function argument lookup within the body of a function.
+    Arg(()),
+    Thunk(ExprId)
+}
+
+/// A trait defining operations on attribute sets within the HIR.
+trait Attrs {
+    /// Inserts a value into the attribute set at a given path.
+    ///
+    /// This method handles the creation of nested attribute sets as needed.
+    /// For example, `insert([a, b], value)` on an empty set results in `{ a = { b = value; }; }`.
+    fn insert(
+        &mut self,
+        path: Vec<Attr>,
+        value: ExprId,
+        ctx: &mut impl DowngradeContext,
+    ) -> Result<()>;
+
+    /// Internal helper for recursively inserting an attribute.
+    fn _insert(
+        &mut self,
+        path: impl Iterator<Item = Attr>,
+        name: Attr,
+        value: ExprId,
+        ctx: &mut impl DowngradeContext,
+    ) -> Result<()>;
+}
+
+impl Attrs for AttrSet {
+    fn _insert(
+        &mut self,
+        mut path: impl Iterator<Item = Attr>,
+        name: Attr,
+        value: ExprId,
+        ctx: &mut impl DowngradeContext,
+    ) -> Result<()> {
+        if let Some(attr) = path.next() {
+            // If the path is not yet exhausted, we need to recurse deeper.
+            match attr {
+                Attr::Str(ident) => {
+                    // If the next attribute is a static string.
+                    if let Some(&id) = self.stcs.get(&ident) {
+                        // If a sub-attrset already exists, recurse into it.
+                        ctx.with_expr_mut(id, |expr, ctx| {
+                            expr.as_mut()
+                                .try_unwrap_attr_set()
+                                .map_err(|_| {
+                                    // This path segment exists but is not an attrset, which is an error.
+                                    Error::downgrade_error(format!(
+                                        "attribute '{}' already defined but is not an attribute set",
+                                        format_symbol(ctx.get_sym(ident))
+                                    ))
+                                })
+                                .and_then(|attrs| attrs._insert(path, name, value, ctx))
+                        })?;
+                    } else {
+                        // Create a new sub-attrset because this path doesn't exist yet.
+                        let mut attrs = AttrSet::default();
+                        attrs._insert(path, name, value, ctx)?;
+                        let attrs = ctx.new_expr(attrs.to_hir());
+                        self.stcs.insert(ident, attrs);
+                    }
+                    Ok(())
+                }
+                Attr::Dynamic(dynamic) => {
+                    // If the next attribute is a dynamic expression, we must create a new sub-attrset.
+                    // We cannot merge with existing dynamic attributes at this stage.
+                    let mut attrs = AttrSet::default();
+                    attrs._insert(path, name, value, ctx)?;
+                    self.dyns.push((dynamic, ctx.new_expr(attrs.to_hir())));
+                    Ok(())
+                }
+            }
+        } else {
+            // This is the final attribute in the path, so insert the value here.
+            match name {
+                Attr::Str(ident) => {
+                    if self.stcs.insert(ident, value).is_some() {
+                        return Err(Error::downgrade_error(format!(
+                            "attribute '{}' already defined",
+                            format_symbol(ctx.get_sym(ident))
+                        )));
+                    }
+                }
+                Attr::Dynamic(dynamic) => {
+                    self.dyns.push((dynamic, value));
+                }
+            }
+            Ok(())
+        }
+    }
+
+    fn insert(
+        &mut self,
+        path: Vec<Attr>,
+        value: ExprId,
+        ctx: &mut impl DowngradeContext,
+    ) -> Result<()> {
+        let mut path = path.into_iter();
+        // The last part of the path is the name of the attribute to be inserted.
+        let name = path.next_back().unwrap();
+        self._insert(path, name, value, ctx)
+    }
+}
+
+/// Represents the different kinds of parameters a function can have in the HIR stage.
+#[derive(Debug)]
+enum Param {
+    /// A simple parameter, e.g., `x: ...`.
+    Ident(String),
+    /// A pattern-matching parameter (formals), e.g., `{ a, b ? 2, ... }@args: ...`.
+    Formals {
+        /// The individual formal parameters, with optional default values.
+        formals: Vec<(String, Option<ExprId>)>,
+        /// Whether an ellipsis (`...`) is present, allowing extra arguments.
+        ellipsis: bool,
+        /// An optional alias for the entire argument set, e.g., `args @ { ... }`.
+        alias: Option<String>,
+    },
+}

evaluator/nixjit_hir/src/utils.rs

@@ -0,0 +1,267 @@
+//! This module provides utility functions for the AST-to-HIR downgrade process.
+//! These functions handle common, often complex, patterns in the `rnix` AST,
+//! such as parsing parameters, attribute sets, and `inherit` statements.
+//! They are helpers to the main `Downgrade` trait implementations.
+
+use hashbrown::HashMap;
+use hashbrown::hash_map::Entry;
+
+use nixjit_value::format_symbol;
+use rnix::ast;
+
+use nixjit_error::{Error, Result};
+use nixjit_ir::{Attr, AttrSet, ConcatStrings, ExprId, Select, Str, SymId, Var};
+
+use crate::Hir;
+
+use super::downgrade::Downgrade;
+use super::{Attrs, DowngradeContext, Param, ToHir};
+
+pub fn maybe_thunk(mut expr: ast::Expr, ctx: &mut impl DowngradeContext) -> Result<ExprId> {
+    use ast::Expr::*;
+    let expr = loop {
+        expr = match expr {
+            Paren(paren) => paren.expr().unwrap(),
+            Root(root) => root.expr().unwrap(),
+            expr => break expr,
+        }
+    };
+    match expr {
+        Error(error) => return Err(self::Error::downgrade_error(error.to_string())),
+        Ident(ident) => return ident.downgrade(ctx),
+        Literal(lit) => return lit.downgrade(ctx),
+        Str(str) => return str.downgrade(ctx),
+        Path(path) => return path.downgrade(ctx),
+
+        _ => (),
+    }
+    let id = match expr {
+        Apply(apply) => apply.downgrade(ctx),
+        Assert(assert) => assert.downgrade(ctx),
+        IfElse(ifelse) => ifelse.downgrade(ctx),
+        Select(select) => select.downgrade(ctx),
+        Lambda(lambda) => lambda.downgrade(ctx),
+        LegacyLet(let_) => let_.downgrade(ctx),
+        LetIn(letin) => letin.downgrade(ctx),
+        List(list) => list.downgrade(ctx),
+        BinOp(op) => op.downgrade(ctx),
+        AttrSet(attrs) => attrs.downgrade(ctx),
+        UnaryOp(op) => op.downgrade(ctx),
+        With(with) => with.downgrade(ctx),
+        HasAttr(has) => has.downgrade(ctx),
+
+        _ => unreachable!(),
+    }?;
+    Ok(ctx.new_expr(Hir::Thunk(id)))
+}
+
+/// Downgrades a function parameter from the AST.
+pub fn downgrade_param(param: ast::Param, ctx: &mut impl DowngradeContext) -> Result<Param> {
+    match param {
+        ast::Param::IdentParam(ident) => Ok(Param::Ident(ident.to_string())),
+        ast::Param::Pattern(pattern) => downgrade_pattern(pattern, ctx),
+    }
+}
+
+/// Downgrades a parameter pattern (formals) from the AST.
+/// This handles `{ a, b ? 2, ... }@args` style parameters.
+pub fn downgrade_pattern(pattern: ast::Pattern, ctx: &mut impl DowngradeContext) -> Result<Param> {
+    // Extract each formal parameter, downgrading its default value if it exists.
+    let formals = pattern
+        .pat_entries()
+        .map(|entry| {
+            let ident = entry.ident().unwrap().to_string();
+            if entry.default().is_none() {
+                Ok((ident, None))
+            } else {
+                entry
+                    .default()
+                    .unwrap()
+                    .downgrade(ctx)
+                    .map(|ok| (ident, Some(ok)))
+            }
+        })
+        .collect::<Result<Vec<_>>>()?;
+    let ellipsis = pattern.ellipsis_token().is_some();
+    let alias = pattern
+        .pat_bind()
+        .map(|alias| alias.ident().unwrap().to_string());
+    Ok(Param::Formals {
+        formals,
+        ellipsis,
+        alias,
+    })
+}
+
+/// Downgrades the entries of an attribute set.
+/// This handles `inherit` and `attrpath = value;` entries.
+pub fn downgrade_attrs(
+    attrs: impl ast::HasEntry,
+    ctx: &mut impl DowngradeContext,
+) -> Result<AttrSet> {
+    let entries = attrs.entries();
+    let mut attrs = AttrSet {
+        stcs: HashMap::new(),
+        dyns: Vec::new(),
+    };
+
+    for entry in entries {
+        match entry {
+            ast::Entry::Inherit(inherit) => downgrade_inherit(inherit, &mut attrs.stcs, ctx)?,
+            ast::Entry::AttrpathValue(value) => downgrade_attrpathvalue(value, &mut attrs, ctx)?,
+        }
+    }
+
+    Ok(attrs)
+}
+
+/// Downgrades attribute set entries for a `let...in` expression.
+/// This is a stricter version of `downgrade_attrs` that disallows dynamic attributes,
+/// as `let` bindings must be statically known.
+pub fn downgrade_static_attrs(
+    attrs: impl ast::HasEntry,
+    ctx: &mut impl DowngradeContext,
+) -> Result<HashMap<SymId, ExprId>> {
+    let entries = attrs.entries();
+    let mut attrs = AttrSet {
+        stcs: HashMap::new(),
+        dyns: Vec::new(),
+    };
+
+    for entry in entries {
+        match entry {
+            ast::Entry::Inherit(inherit) => downgrade_inherit(inherit, &mut attrs.stcs, ctx)?,
+            ast::Entry::AttrpathValue(value) => {
+                downgrade_static_attrpathvalue(value, &mut attrs, ctx)?
+            }
+        }
+    }
+
+    Ok(attrs.stcs)
+}
+
+/// Downgrades an `inherit` statement.
+/// `inherit (from) a b;` is translated into `a = from.a; b = from.b;`.
+/// `inherit a b;` is translated into `a = a; b = b;` (i.e., bringing variables into scope).
+pub fn downgrade_inherit(
+    inherit: ast::Inherit,
+    stcs: &mut HashMap<SymId, ExprId>,
+    ctx: &mut impl DowngradeContext,
+) -> Result<()> {
+    // Downgrade the `from` expression if it exists.
+    let from = if let Some(from) = inherit.from() {
+        Some(from.expr().unwrap().downgrade(ctx)?)
+    } else {
+        None
+    };
+    for attr in inherit.attrs() {
+        let ident = match downgrade_attr(attr, ctx)? {
+            Attr::Str(ident) => ident,
+            _ => {
+                // `inherit` does not allow dynamic attributes.
+                return Err(Error::downgrade_error(
+                    "dynamic attributes not allowed in inherit".to_string(),
+                ));
+            }
+        };
+        let expr = from.as_ref().map_or_else(
+            // If `from` is None, `inherit foo;` becomes `foo = foo;`.
+            || Var { sym: ident.clone() }.to_hir(),
+            // If `from` is Some, `inherit (from) foo;` becomes `foo = from.foo;`.
+            |&expr| {
+                Select {
+                    expr,
+                    attrpath: vec![Attr::Str(ident.clone())],
+                    default: None,
+                }
+                .to_hir()
+            },
+        );
+        match stcs.entry(ident) {
+            Entry::Occupied(occupied) => {
+                return Err(Error::eval_error(format!(
+                    "attribute '{}' already defined",
+                    format_symbol(ctx.get_sym(*occupied.key()))
+                )));
+            }
+            Entry::Vacant(vacant) => vacant.insert(ctx.new_expr(expr)),
+        };
+    }
+    Ok(())
+}
+
+/// Downgrades a single attribute key (part of an attribute path).
+/// An attribute can be a static identifier, an interpolated string, or a dynamic expression.
+pub fn downgrade_attr(attr: ast::Attr, ctx: &mut impl DowngradeContext) -> Result<Attr> {
+    use ast::Attr::*;
+    use ast::InterpolPart::*;
+    match attr {
+        Ident(ident) => Ok(Attr::Str(ctx.new_sym(ident.to_string()))),
+        Str(string) => {
+            let parts = string.normalized_parts();
+            if parts.is_empty() {
+                Ok(Attr::Str(ctx.new_sym("".into())))
+            } else if parts.len() == 1 {
+                // If the string has only one part, it's either a literal or a single interpolation.
+                match parts.into_iter().next().unwrap() {
+                    Literal(ident) => Ok(Attr::Str(ctx.new_sym(ident))),
+                    Interpolation(interpol) => {
+                        Ok(Attr::Dynamic(interpol.expr().unwrap().downgrade(ctx)?))
+                    }
+                }
+            } else {
+                // If the string has multiple parts, it's an interpolated string that must be concatenated.
+                let parts = parts
+                    .into_iter()
+                    .map(|part| match part {
+                        Literal(lit) => Ok(ctx.new_expr(self::Str { val: lit }.to_hir())),
+                        Interpolation(interpol) => interpol.expr().unwrap().downgrade(ctx),
+                    })
+                    .collect::<Result<Vec<_>>>()?;
+                Ok(Attr::Dynamic(
+                    ctx.new_expr(ConcatStrings { parts }.to_hir()),
+                ))
+            }
+        }
+        Dynamic(dynamic) => Ok(Attr::Dynamic(dynamic.expr().unwrap().downgrade(ctx)?)),
+    }
+}
+
+/// Downgrades an attribute path (e.g., `a.b."${c}".d`) into a `Vec<Attr>`.
+pub fn downgrade_attrpath(
+    attrpath: ast::Attrpath,
+    ctx: &mut impl DowngradeContext,
+) -> Result<Vec<Attr>> {
+    attrpath
+        .attrs()
+        .map(|attr| downgrade_attr(attr, ctx))
+        .collect::<Result<Vec<_>>>()
+}
+
+/// Downgrades an `attrpath = value;` expression and inserts it into an `AttrSet`.
+pub fn downgrade_attrpathvalue(
+    value: ast::AttrpathValue,
+    attrs: &mut AttrSet,
+    ctx: &mut impl DowngradeContext,
+) -> Result<()> {
+    let path = downgrade_attrpath(value.attrpath().unwrap(), ctx)?;
+    let value = maybe_thunk(value.value().unwrap(), ctx)?;
+    attrs.insert(path, value, ctx)
+}
+
+/// A stricter version of `downgrade_attrpathvalue` for `let...in` bindings.
+/// It ensures that the attribute path contains no dynamic parts.
+pub fn downgrade_static_attrpathvalue(
+    value: ast::AttrpathValue,
+    attrs: &mut AttrSet,
+    ctx: &mut impl DowngradeContext,
+) -> Result<()> {
+    let path = downgrade_attrpath(value.attrpath().unwrap(), ctx)?;
+    if path.iter().any(|attr| matches!(attr, Attr::Dynamic(_))) {
+        return Err(Error::downgrade_error(
+            "dynamic attributes not allowed in let bindings".to_string(),
+        ));
+    }
+    let value = value.value().unwrap().downgrade(ctx)?;
+    attrs.insert(path, value, ctx)
+}

evaluator/nixjit_ir/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "nixjit_ir"
+description = "The core data structures for the nixjit intermediate representation (IR)."
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+derive_more = { version = "2.0", features = ["full"] }
+hashbrown = "0.15"
+rnix = "0.12"
+
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_ir/src/lib.rs

@@ -0,0 +1,362 @@
+//! This crate defines the core data structures for the nixjit Intermediate Representation (IR).
+//!
+//! The IR provides a simplified, language-agnostic representation of Nix expressions,
+//! serving as a bridge between the high-level representation (HIR) and the low-level
+//! representation (LIR). It defines the fundamental building blocks like expression IDs,
+//! argument indices, and structures for various expression types (e.g., binary operations,
+//! attribute sets, function calls).
+//!
+//! These structures are designed to be generic and reusable across different stages of
+//! the compiler.
+
+use rnix::ast;
+
+use derive_more::TryUnwrap;
+use hashbrown::{HashMap, HashSet};
+
+use nixjit_value::Const as PubConst;
+
+/// A type-safe wrapper for an index into an expression table.
+///
+/// Using a newtype wrapper to prevent accidentally mixing up different kinds of indices.
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct ExprId(usize);
+
+impl ExprId {
+    /// Returns the raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible for using this index correctly and not causing out-of-bounds access.
+    #[inline(always)]
+    pub unsafe fn raw(self) -> usize {
+        self.0
+    }
+
+    /// Creates an `ExprId` from a raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that the provided index is valid for the expression table.
+    #[inline(always)]
+    pub unsafe fn from_raw(id: usize) -> Self {
+        Self(id)
+    }
+}
+
+/// A type-safe wrapper for an index into an symbol table.
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct SymId(usize);
+
+impl SymId {
+    /// Returns the raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible for using this index correctly and not causing out-of-bounds access.
+    #[inline(always)]
+    pub unsafe fn raw(self) -> usize {
+        self.0
+    }
+
+    /// Creates an `SymId` from a raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that the provided index is valid for the symbol table.
+    #[inline(always)]
+    pub unsafe fn from_raw(id: usize) -> Self {
+        Self(id)
+    }
+}
+
+/// A type-safe wrapper for an index into a primop (builtin function) table.
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct PrimOpId(usize);
+
+impl PrimOpId {
+    /// Returns the raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible for using this index correctly.
+    #[inline(always)]
+    pub unsafe fn raw(self) -> usize {
+        self.0
+    }
+
+    /// Creates a `PrimOpId` from a raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that the provided index is valid.
+    #[inline(always)]
+    pub unsafe fn from_raw(id: usize) -> Self {
+        Self(id)
+    }
+}
+
+/// A type-safe wrapper for an index into a function's dependency stack.
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct StackIdx(usize);
+
+impl StackIdx {
+    /// Returns the raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible for using this index correctly.
+    #[inline(always)]
+    pub unsafe fn raw(self) -> usize {
+        self.0
+    }
+
+    /// Creates an `StackIdx` from a raw `usize` index.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that the provided index is valid.
+    #[inline(always)]
+    pub unsafe fn from_raw(idx: usize) -> Self {
+        Self(idx)
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct Arg;
+
+/// Represents a Nix attribute set.
+#[derive(Debug, Default)]
+pub struct AttrSet {
+    /// Statically known attributes (key is a string).
+    pub stcs: HashMap<SymId, ExprId>,
+    /// Dynamically computed attributes, where both the key and value are expressions.
+    pub dyns: Vec<(ExprId, ExprId)>,
+}
+
+/// Represents a key in an attribute path.
+#[derive(Debug, TryUnwrap)]
+pub enum Attr {
+    /// A dynamic attribute key, which is an expression that must evaluate to a string.
+    /// Example: `attrs.${key}`
+    Dynamic(ExprId),
+    /// A static attribute key.
+    /// Example: `attrs.key`
+    Str(SymId),
+}
+
+/// Represents a Nix list.
+#[derive(Debug)]
+pub struct List {
+    /// The expressions that are elements of the list.
+    pub items: Vec<ExprId>,
+}
+
+/// Represents a "has attribute" check (`?` operator).
+#[derive(Debug)]
+pub struct HasAttr {
+    /// The expression to check for the attribute (the left-hand side).
+    pub lhs: ExprId,
+    /// The attribute path to look for (the right-hand side).
+    pub rhs: Vec<Attr>,
+}
+
+/// Represents a binary operation.
+#[derive(Debug)]
+pub struct BinOp {
+    pub lhs: ExprId,
+    pub rhs: ExprId,
+    pub kind: BinOpKind,
+}
+
+/// The kinds of binary operations supported in Nix.
+#[derive(Clone, Debug)]
+pub enum BinOpKind {
+    // Arithmetic
+    Add,
+    Sub,
+    Div,
+    Mul,
+
+    // Comparison
+    Eq,
+    Neq,
+    Lt,
+    Gt,
+    Leq,
+    Geq,
+
+    // Logical
+    And,
+    Or,
+    Impl,
+
+    // Set/String/Path operations
+    Con, // List concatenation (`++`)
+    Upd, // AttrSet update (`//`)
+
+    // Not standard, but part of rnix AST
+    PipeL,
+    PipeR,
+}
+
+impl From<ast::BinOpKind> for BinOpKind {
+    fn from(op: ast::BinOpKind) -> Self {
+        use BinOpKind::*;
+        use ast::BinOpKind as kind;
+        match op {
+            kind::Concat => Con,
+            kind::Update => Upd,
+            kind::Add => Add,
+            kind::Sub => Sub,
+            kind::Mul => Mul,
+            kind::Div => Div,
+            kind::And => And,
+            kind::Equal => Eq,
+            kind::Implication => Impl,
+            kind::Less => Lt,
+            kind::LessOrEq => Leq,
+            kind::More => Gt,
+            kind::MoreOrEq => Geq,
+            kind::NotEqual => Neq,
+            kind::Or => Or,
+            kind::PipeLeft => PipeL,
+            kind::PipeRight => PipeR,
+        }
+    }
+}
+
+/// Represents a unary operation.
+#[derive(Debug)]
+pub struct UnOp {
+    pub rhs: ExprId,
+    pub kind: UnOpKind,
+}
+
+/// The kinds of unary operations.
+#[derive(Clone, Debug)]
+pub enum UnOpKind {
+    Neg, // Negation (`-`)
+    Not, // Logical not (`!`)
+}
+
+impl From<ast::UnaryOpKind> for UnOpKind {
+    fn from(value: ast::UnaryOpKind) -> Self {
+        match value {
+            ast::UnaryOpKind::Invert => UnOpKind::Not,
+            ast::UnaryOpKind::Negate => UnOpKind::Neg,
+        }
+    }
+}
+
+/// Represents an attribute selection from an attribute set.
+#[derive(Debug)]
+pub struct Select {
+    /// The expression that should evaluate to an attribute set.
+    pub expr: ExprId,
+    /// The path of attributes to select.
+    pub attrpath: Vec<Attr>,
+    /// An optional default value to return if the selection fails.
+    pub default: Option<ExprId>,
+}
+
+/// Represents an `if-then-else` expression.
+#[derive(Debug)]
+pub struct If {
+    pub cond: ExprId,
+    pub consq: ExprId, // Consequence (then branch)
+    pub alter: ExprId, // Alternative (else branch)
+}
+
+/// Represents a function value (a lambda).
+#[derive(Debug)]
+pub struct Func {
+    /// The body of the function
+    pub body: ExprId,
+    /// The parameter specification for the function.
+    pub param: Param,
+
+    pub arg: ExprId,
+}
+
+/// Describes the parameters of a function.
+#[derive(Debug)]
+pub struct Param {
+    /// The name of the argument if it's a simple identifier (e.g., `x: ...`).
+    /// Also used for the alias in a pattern (e.g., `args @ { ... }`).
+    pub ident: Option<SymId>,
+    /// The set of required parameter names for a pattern-matching function.
+    pub required: Option<Vec<SymId>>,
+    /// The set of all allowed parameter names for a non-ellipsis pattern-matching function.
+    /// If `None`, any attribute is allowed (ellipsis `...` is present).
+    pub allowed: Option<HashSet<SymId>>,
+}
+
+/// Represents a function call.
+#[derive(Debug)]
+pub struct Call {
+    /// The expression that evaluates to the function to be called.
+    pub func: ExprId,
+    pub arg: ExprId,
+}
+
+/// Represents a `with` expression.
+#[derive(Debug)]
+pub struct With {
+    /// The namespace to bring into scope.
+    pub namespace: ExprId,
+    /// The expression to be evaluated within the new scope.
+    pub expr: ExprId,
+}
+
+/// Represents an `assert` expression.
+#[derive(Debug)]
+pub struct Assert {
+    /// The condition to assert.
+    pub assertion: ExprId,
+    /// The expression to return if the assertion is true.
+    pub expr: ExprId,
+}
+
+/// Represents the concatenation of multiple string expressions.
+/// This is typically the result of downgrading an interpolated string.
+#[derive(Debug)]
+pub struct ConcatStrings {
+    pub parts: Vec<ExprId>,
+}
+
+/// Represents a constant value (e.g., integer, float, boolean, null).
+#[derive(Clone, Copy, Debug)]
+pub struct Const {
+    pub val: PubConst,
+}
+
+impl<T: Into<PubConst>> From<T> for Const {
+    fn from(value: T) -> Self {
+        Self { val: value.into() }
+    }
+}
+
+/// Represents a simple, non-interpolated string literal.
+#[derive(Debug)]
+pub struct Str {
+    pub val: String,
+}
+
+/// Represents a variable lookup by its name.
+#[derive(Debug)]
+pub struct Var {
+    pub sym: SymId,
+}
+
+/// Represents a path literal.
+#[derive(Debug)]
+pub struct Path {
+    /// The expression that evaluates to the string content of the path.
+    /// This can be a simple `Str` or a `ConcatStrings` for interpolated paths.
+    pub expr: ExprId,
+}

evaluator/nixjit_jit/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "nixjit_jit"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+hashbrown = "0.15"
+
+cranelift = "0.122"
+cranelift-module = "0.122"
+cranelift-jit = "0.122"
+cranelift-native = "0.122"
+
+nixjit_error = { path = "../nixjit_error" }
+nixjit_eval = { path = "../nixjit_eval" }
+nixjit_hir = { path = "../nixjit_hir" }
+nixjit_ir = { path = "../nixjit_ir" }
+nixjit_lir = { path = "../nixjit_lir" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_jit/src/compile.rs

@@ -0,0 +1,559 @@
+//! This module defines the `JITCompile` trait and its implementations for
+//! various IR types. It provides the translation from LIR to Cranelift IR.
+
+use cranelift::codegen::ir::{self, StackSlot};
+use cranelift::prelude::*;
+
+use nixjit_eval::Value;
+use nixjit_ir::*;
+use nixjit_lir::Lir;
+
+use super::{Context, JITContext};
+
+/// A trait for compiling IR nodes to Cranelift IR.
+///
+/// This trait defines how different IR nodes should be compiled to
+/// Cranelift IR instructions that can be executed by the JIT compiler.
+pub trait JITCompile<Ctx: JITContext> {
+    /// Compiles the IR node to Cranelift IR.
+    ///
+    /// # Arguments
+    /// * `ctx` - The compilation context
+    /// * `rt_ctx` - The evaluation context value
+    /// * `env` - The environment value
+    ///
+    /// # Returns
+    /// A stack slot containing the compiled result
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot;
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for ExprId {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Lir {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for AttrSet {
+    /// Compiles an attribute set to Cranelift IR.
+    ///
+    /// This creates a new attribute set and compiles all static attributes into it.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let attrs = ctx.create_attrs();
+        for (&k, v) in self.stcs.iter() {
+            let v = v.compile(ctx, rt_ctx);
+            ctx.push_attr(attrs, k, v);
+        }
+        ctx.finalize_attrs(attrs)
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for List {
+    /// Compiles a list to Cranelift IR.
+    ///
+    /// This creates a new list by compiling all items and storing them in an array.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let array = ctx.alloc_array(self.items.len());
+        for (i, item) in self.items.iter().enumerate() {
+            let item = item.compile(ctx, rt_ctx);
+            let tag = ctx.builder.ins().stack_load(types::I64, item, 0);
+            let val0 = ctx.builder.ins().stack_load(types::I64, item, 8);
+            let val1 = ctx.builder.ins().stack_load(types::I64, item, 16);
+            let val2 = ctx.builder.ins().stack_load(types::I64, item, 24);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), tag, array, i as i32 * 32);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val0, array, i as i32 * 32 + 8);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val1, array, i as i32 * 32 + 16);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val2, array, i as i32 * 32 + 24);
+        }
+        ctx.create_list(array, self.items.len())
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for HasAttr {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for BinOp {
+    /// Compiles a binary operation to Cranelift IR.
+    ///
+    /// This implementation handles various binary operations like addition, subtraction,
+    /// division, logical AND/OR, and equality checks. It generates code that checks
+    /// the types of operands and performs the appropriate operation.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        use BinOpKind::*;
+        let lhs = self.lhs.compile(ctx, rt_ctx);
+        let rhs = self.rhs.compile(ctx, rt_ctx);
+        let lhs_tag = ctx.get_tag(lhs);
+        let rhs_tag = ctx.get_tag(rhs);
+        let eq = ctx.builder.ins().icmp(IntCC::Equal, lhs_tag, rhs_tag);
+
+        let eq_block = ctx.builder.create_block();
+        let neq_block = ctx.builder.create_block();
+        let exit_block = ctx.builder.create_block();
+        ctx.builder.ins().brif(eq, eq_block, [], neq_block, []);
+
+        match self.kind {
+            Add => {
+                ctx.builder.switch_to_block(eq_block);
+                let default_block = ctx.builder.create_block();
+                let int_block = ctx.builder.create_block();
+                let float_block = ctx.builder.create_block();
+                let float_check_block = ctx.builder.create_block();
+
+                let is_int = ctx
+                    .builder
+                    .ins()
+                    .icmp_imm(IntCC::Equal, lhs_tag, Value::INT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_int, int_block, [], float_check_block, []);
+
+                ctx.builder.switch_to_block(int_block);
+                let lhs_value = ctx.get_small_value(types::I64, lhs);
+                let rhs_value = ctx.get_small_value(types::I64, rhs);
+                let result = ctx.builder.ins().iadd(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: Non-float
+                ctx.builder.switch_to_block(float_check_block);
+                let is_float =
+                    ctx.builder
+                        .ins()
+                        .icmp_imm(IntCC::Equal, lhs_tag, Value::FLOAT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_float, float_block, [], default_block, []);
+
+                ctx.builder.switch_to_block(float_block);
+                let lhs_value = ctx.get_small_value(types::F64, lhs);
+                let rhs_value = ctx.get_small_value(types::F64, rhs);
+                let result = ctx.builder.ins().fadd(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: finish this
+                ctx.builder.switch_to_block(default_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.switch_to_block(neq_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.seal_block(default_block);
+                ctx.builder.seal_block(int_block);
+                ctx.builder.seal_block(float_check_block);
+                ctx.builder.seal_block(float_block);
+            }
+            Sub => {
+                ctx.builder.switch_to_block(eq_block);
+                let default_block = ctx.builder.create_block();
+                let int_block = ctx.builder.create_block();
+                let float_block = ctx.builder.create_block();
+                let float_check_block = ctx.builder.create_block();
+
+                let is_int = ctx
+                    .builder
+                    .ins()
+                    .icmp_imm(IntCC::Equal, lhs_tag, Value::INT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_int, int_block, [], float_check_block, []);
+
+                ctx.builder.switch_to_block(int_block);
+                let lhs_value = ctx.get_small_value(types::I64, lhs);
+                let rhs_value = ctx.get_small_value(types::I64, rhs);
+                let result = ctx.builder.ins().isub(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: Non-float
+                ctx.builder.switch_to_block(float_check_block);
+                let is_float =
+                    ctx.builder
+                        .ins()
+                        .icmp_imm(IntCC::Equal, lhs_tag, Value::FLOAT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_float, float_block, [], default_block, []);
+
+                ctx.builder.switch_to_block(float_block);
+                let lhs_value = ctx.get_small_value(types::F64, lhs);
+                let rhs_value = ctx.get_small_value(types::F64, rhs);
+                let result = ctx.builder.ins().fsub(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: finish this
+                ctx.builder.switch_to_block(default_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.switch_to_block(neq_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.seal_block(default_block);
+                ctx.builder.seal_block(int_block);
+                ctx.builder.seal_block(float_check_block);
+                ctx.builder.seal_block(float_block);
+            }
+            Div => {
+                ctx.builder.switch_to_block(eq_block);
+                let default_block = ctx.builder.create_block();
+                let int_block = ctx.builder.create_block();
+                let float_block = ctx.builder.create_block();
+                let float_check_block = ctx.builder.create_block();
+
+                let is_int = ctx
+                    .builder
+                    .ins()
+                    .icmp_imm(IntCC::Equal, lhs_tag, Value::INT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_int, int_block, [], float_check_block, []);
+
+                ctx.builder.switch_to_block(int_block);
+                let lhs_value = ctx.get_small_value(types::I64, lhs);
+                let rhs_value = ctx.get_small_value(types::I64, rhs);
+                let result = ctx.builder.ins().sdiv(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: Non-float
+                ctx.builder.switch_to_block(float_check_block);
+                let is_float =
+                    ctx.builder
+                        .ins()
+                        .icmp_imm(IntCC::Equal, lhs_tag, Value::FLOAT as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_float, float_block, [], default_block, []);
+
+                ctx.builder.switch_to_block(float_block);
+                let lhs_value = ctx.get_small_value(types::F64, lhs);
+                let rhs_value = ctx.get_small_value(types::F64, rhs);
+                let result = ctx.builder.ins().fdiv(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, &[]);
+
+                // FIXME: finish this
+                ctx.builder.switch_to_block(default_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.switch_to_block(neq_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.seal_block(default_block);
+                ctx.builder.seal_block(int_block);
+                ctx.builder.seal_block(float_check_block);
+                ctx.builder.seal_block(float_block);
+            }
+            And => {
+                ctx.builder.switch_to_block(eq_block);
+                let bool_block = ctx.builder.create_block();
+                let non_bool_block = ctx.builder.create_block();
+
+                let is_bool = ctx
+                    .builder
+                    .ins()
+                    .icmp_imm(IntCC::Equal, lhs_tag, Value::BOOL as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_bool, bool_block, [], non_bool_block, []);
+
+                ctx.builder.switch_to_block(bool_block);
+                let lhs_value = ctx.get_small_value(types::I64, lhs);
+                let rhs_value = ctx.get_small_value(types::I64, rhs);
+                let result = ctx.builder.ins().band(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, []);
+
+                ctx.builder.switch_to_block(non_bool_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.switch_to_block(neq_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.seal_block(bool_block);
+                ctx.builder.seal_block(non_bool_block);
+            }
+            Or => {
+                ctx.builder.switch_to_block(eq_block);
+                let bool_block = ctx.builder.create_block();
+                let non_bool_block = ctx.builder.create_block();
+
+                let is_bool = ctx
+                    .builder
+                    .ins()
+                    .icmp_imm(IntCC::Equal, lhs_tag, Value::BOOL as i64);
+                ctx.builder
+                    .ins()
+                    .brif(is_bool, bool_block, [], non_bool_block, []);
+
+                ctx.builder.switch_to_block(bool_block);
+                let lhs_value = ctx.get_small_value(types::I64, lhs);
+                let rhs_value = ctx.get_small_value(types::I64, rhs);
+                let result = ctx.builder.ins().bor(lhs_value, rhs_value);
+                ctx.builder.ins().stack_store(lhs_tag, lhs, 0);
+                ctx.builder.ins().stack_store(result, lhs, 8);
+                ctx.builder.ins().jump(exit_block, []);
+
+                ctx.builder.switch_to_block(non_bool_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.switch_to_block(neq_block);
+                ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+                ctx.builder.seal_block(bool_block);
+                ctx.builder.seal_block(non_bool_block);
+            }
+            Eq => {
+                ctx.builder.switch_to_block(eq_block);
+                ctx.eq(lhs, rhs);
+                ctx.builder.ins().jump(exit_block, []);
+                ctx.builder.switch_to_block(neq_block);
+                ctx.eq(lhs, rhs);
+                ctx.builder.ins().jump(exit_block, []);
+            }
+            _ => todo!(),
+        }
+
+        ctx.builder.seal_block(exit_block);
+        ctx.builder.seal_block(eq_block);
+        ctx.builder.seal_block(neq_block);
+        ctx.builder.switch_to_block(exit_block);
+        ctx.free_slot(rhs);
+
+        lhs
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for UnOp {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Attr {
+    /// Compiles an attribute key to Cranelift IR.
+    ///
+    /// An attribute can be either a static string or a dynamic expression.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        use Attr::*;
+        match self {
+            Str(string) => ctx.create_string(string),
+            Dynamic(ir) => ir.compile(ctx, rt_ctx),
+        }
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Select {
+    /// Compiles an attribute selection to Cranelift IR.
+    ///
+    /// This compiles the expression to select from, builds the attribute path,
+    /// and calls the select helper function.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let val = self.expr.compile(ctx, rt_ctx);
+        let attrpath = ctx.alloc_array(self.attrpath.len());
+        for (i, attr) in self.attrpath.iter().enumerate() {
+            let arg = attr.compile(ctx, rt_ctx);
+            let tag = ctx.builder.ins().stack_load(types::I64, arg, 0);
+            let val0 = ctx.builder.ins().stack_load(types::I64, arg, 8);
+            let val1 = ctx.builder.ins().stack_load(types::I64, arg, 16);
+            let val2 = ctx.builder.ins().stack_load(types::I64, arg, 24);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), tag, attrpath, i as i32 * 32);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val0, attrpath, i as i32 * 32 + 8);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val1, attrpath, i as i32 * 32 + 16);
+            ctx.builder
+                .ins()
+                .store(MemFlags::new(), val2, attrpath, i as i32 * 32 + 24);
+        }
+        ctx.select(val, attrpath, self.attrpath.len(), rt_ctx);
+        val
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for If {
+    /// Compiles an if-expression to Cranelift IR.
+    ///
+    /// This generates code that evaluates the condition, checks that it's a boolean,
+    /// and then jumps to the appropriate branch (true or false).
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let cond = self.cond.compile(ctx, rt_ctx);
+        let cond_type = ctx.builder.ins().stack_load(types::I64, cond, 0);
+        let cond_value = ctx.builder.ins().stack_load(types::I64, cond, 8);
+
+        let true_block = ctx.builder.create_block();
+        let false_block = ctx.builder.create_block();
+        let exit_block = ctx.builder.create_block();
+        let error_block = ctx.builder.create_block();
+        let judge_block = ctx.builder.create_block();
+        let slot = ctx.alloca();
+
+        let is_bool = ctx
+            .builder
+            .ins()
+            .icmp_imm(IntCC::Equal, cond_type, Value::BOOL as i64);
+        ctx.builder
+            .ins()
+            .brif(is_bool, judge_block, [], error_block, []);
+
+        ctx.builder.switch_to_block(judge_block);
+        ctx.builder
+            .ins()
+            .brif(cond_value, true_block, [], false_block, []);
+
+        ctx.builder.switch_to_block(true_block);
+        let ret = self.consq.compile(ctx, rt_ctx);
+        let tag = ctx.builder.ins().stack_load(types::I64, ret, 0);
+        let val0 = ctx.builder.ins().stack_load(types::I64, ret, 8);
+        let val1 = ctx.builder.ins().stack_load(types::I64, ret, 16);
+        let val2 = ctx.builder.ins().stack_load(types::I64, ret, 24);
+        ctx.builder.ins().stack_store(tag, slot, 0);
+        ctx.builder.ins().stack_store(val0, slot, 8);
+        ctx.builder.ins().stack_store(val1, slot, 16);
+        ctx.builder.ins().stack_store(val2, slot, 24);
+        ctx.builder.ins().jump(exit_block, []);
+
+        ctx.builder.switch_to_block(false_block);
+        let ret = self.alter.compile(ctx, rt_ctx);
+        let tag = ctx.builder.ins().stack_load(types::I64, ret, 0);
+        let val0 = ctx.builder.ins().stack_load(types::I64, ret, 8);
+        let val1 = ctx.builder.ins().stack_load(types::I64, ret, 16);
+        let val2 = ctx.builder.ins().stack_load(types::I64, ret, 24);
+        ctx.builder.ins().stack_store(tag, slot, 0);
+        ctx.builder.ins().stack_store(val0, slot, 8);
+        ctx.builder.ins().stack_store(val1, slot, 16);
+        ctx.builder.ins().stack_store(val2, slot, 24);
+        ctx.builder.ins().jump(exit_block, []);
+
+        ctx.builder.switch_to_block(error_block);
+        ctx.builder.ins().trap(TrapCode::unwrap_user(1));
+
+        ctx.builder.switch_to_block(exit_block);
+        slot
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Call {
+    /// Compiles a function call to Cranelift IR.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let func = self.func.compile(ctx, rt_ctx);
+        let arg = self.arg.compile(ctx, rt_ctx);
+        ctx.call(func, arg, rt_ctx);
+        func
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for With {
+    /// Compiles a `with` expression to Cranelift IR.
+    ///
+    /// This enters a new `with` scope with the compiled namespace, compiles the body expression,
+    /// and then exits the `with` scope.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        let namespace = self.namespace.compile(ctx, rt_ctx);
+        ctx.enter_with(rt_ctx, namespace);
+        let ret = self.expr.compile(ctx, rt_ctx);
+        ctx.exit_with(rt_ctx);
+        ctx.free_slot(namespace);
+        ret
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Assert {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for ConcatStrings {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Const {
+    /// Compiles a constant value to Cranelift IR.
+    ///
+    /// This handles boolean, integer, float, and null constants by storing
+    /// their values and type tags in a stack slot.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        use nixjit_value::Const::*;
+        let slot = ctx.alloca();
+        match self.val {
+            Bool(x) => {
+                let tag = ctx.builder.ins().iconst(types::I64, Value::BOOL as i64);
+                let val = ctx.builder.ins().iconst(types::I64, x as i64);
+                ctx.builder.ins().stack_store(tag, slot, 0);
+                ctx.builder.ins().stack_store(val, slot, 8);
+            }
+            Int(x) => {
+                let tag = ctx.builder.ins().iconst(types::I64, Value::INT as i64);
+                let val = ctx.builder.ins().iconst(types::I64, x);
+                ctx.builder.ins().stack_store(tag, slot, 0);
+                ctx.builder.ins().stack_store(val, slot, 8);
+            }
+            Float(x) => {
+                let tag = ctx.builder.ins().iconst(types::I64, Value::FLOAT as i64);
+                let val = ctx.builder.ins().f64const(x);
+                ctx.builder.ins().stack_store(tag, slot, 0);
+                ctx.builder.ins().stack_store(val, slot, 8);
+            }
+            Null => {
+                let tag = ctx.builder.ins().iconst(types::I64, Value::NULL as i64);
+                ctx.builder.ins().stack_store(tag, slot, 0);
+            }
+        }
+        slot
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Str {
+    /// Compiles a string literal to Cranelift IR.
+    ///
+    /// This creates a string value from the string literal.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        ctx.create_string(&self.val)
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Var {
+    /// Compiles a variable lookup to Cranelift IR.
+    ///
+    /// This looks up a variable by its symbol in the current environment.
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        ctx.lookup(rt_ctx, &self.sym)
+    }
+}
+
+impl<Ctx: JITContext> JITCompile<Ctx> for Path {
+    fn compile(&self, ctx: &mut Context<Ctx>, rt_ctx: ir::Value) -> StackSlot {
+        todo!()
+    }
+}

evaluator/nixjit_jit/src/helpers.rs

@@ -0,0 +1,237 @@
+//! Helper functions for the JIT compiler.
+//!
+//! These functions are called from JIT-compiled code to perform operations
+//! that are difficult or unsafe to do directly in the generated IR.
+
+use core::{slice, str};
+use std::alloc::Layout;
+use std::alloc::alloc;
+use std::mem::MaybeUninit;
+use std::ptr::NonNull;
+
+use hashbrown::HashMap;
+
+use nixjit_eval::{AttrSet, EvalContext, List, Value};
+use nixjit_ir::ExprId;
+use nixjit_ir::SymId;
+
+use super::JITContext;
+
+/// Helper function to call a function with arguments.
+pub extern "C" fn helper_call<Ctx: JITContext>(
+    func: &mut Value,
+    arg: NonNull<Value>,
+    ctx: &mut Ctx,
+) {
+    // SAFETY: The `arg` pointer is guaranteed to be valid and non-null by the JIT compiler,
+    // which allocates it on the stack. The JIT code ensures that the pointer points to a
+    // valid `Value` and that its lifetime is managed correctly within the compiled function.
+    func.call(unsafe { arg.read() }, ctx).unwrap();
+}
+
+/// Helper function to look up a function argument.
+///
+/// This function is called from JIT-compiled code to access function arguments.
+pub extern "C" fn helper_lookup_arg<Ctx: EvalContext>(ctx: &mut Ctx, ret: &mut MaybeUninit<Value>) {
+    todo!()
+    // ret.write(ctx.lookup_arg().unwrap().clone());
+}
+
+/// Helper function to look up a variable by name.
+///
+/// This function is called from JIT-compiled code to perform variable lookups
+/// in the current scope and `with` expression scopes.
+pub extern "C" fn helper_lookup<Ctx: JITContext>(
+    ctx: &Ctx,
+    sym_ptr: *const u8,
+    sym_len: usize,
+    ret: &mut MaybeUninit<Value>,
+) {
+    // TODO: Error Handling
+    // SAFETY: The `sym_ptr` and `sym_len` are provided by the JIT compiler and are
+    // guaranteed to form a valid UTF-8 string slice. The string data is embedded
+    // in the compiled code and has a static lifetime, ensuring the pointer is always valid.
+    unsafe {
+        ret.write(
+            ctx.lookup_with(str::from_utf8_unchecked(slice::from_raw_parts(
+                sym_ptr, sym_len,
+            )))
+            .unwrap()
+            .clone(),
+        );
+    }
+}
+
+/// Helper function to perform attribute selection.
+///
+/// This function is called from JIT-compiled code to select attributes from
+/// an attribute set using a path of attribute names.
+pub extern "C" fn helper_select<Ctx: JITContext>(
+    val: &mut Value,
+    path_ptr: *mut Value,
+    path_len: usize,
+    ctx: &mut Ctx,
+) {
+    let path = core::ptr::slice_from_raw_parts_mut(path_ptr, path_len);
+    // SAFETY: The `path_ptr` is allocated by the JIT compiler using `helper_alloc_array`
+    // and is guaranteed to be valid for the given length. The `Box::from_raw` call
+    // correctly takes ownership of the allocated slice, ensuring it is properly deallocated.
+    let path = unsafe { Box::from_raw(path) };
+    for attr in path {
+        val.select(&attr.force_string_no_ctx().unwrap(), ctx)
+            .unwrap();
+    }
+}
+
+/// Helper function to perform attribute selection with a default value.
+///
+/// This function is called from JIT-compiled code to select attributes from
+/// an attribute set, returning a default value if the selection fails.
+pub extern "C" fn helper_select_with_default<Ctx: JITContext>(
+    val: &mut Value,
+    path_ptr: *mut Value,
+    path_len: usize,
+    default: ExprId,
+    ctx: &mut Ctx,
+) {
+    let path = core::ptr::slice_from_raw_parts_mut(path_ptr, path_len);
+    // SAFETY: The `path_ptr` is allocated by the JIT compiler using `helper_alloc_array`
+    // and is guaranteed to be valid for the given length. The `Box::from_raw` call
+    // correctly takes ownership of the allocated slice, ensuring it is properly deallocated.
+    let path = unsafe { Box::from_raw(path) };
+    for attr in path {
+        val.select_or(&attr.force_string_no_ctx().unwrap(), default, ctx)
+            .unwrap();
+    }
+}
+
+/// Helper function to check equality between two values.
+///
+/// This function is called from JIT-compiled code to perform equality comparisons.
+pub extern "C" fn helper_eq(lhs: &mut Value, rhs: NonNull<Value>) {
+    // SAFETY: The `rhs` pointer is guaranteed to be valid and non-null by the JIT compiler,
+    // which allocates it on the stack. The JIT code ensures that the pointer points to a
+    // valid `Value` and that its lifetime is managed correctly within the compiled function.
+    lhs.eq(unsafe { rhs.read() });
+}
+
+/// Helper function to create a string value.
+///
+/// This function is called from JIT-compiled code to create string values
+/// from raw byte arrays.
+pub unsafe extern "C" fn helper_create_string(
+    ptr: *const u8,
+    len: usize,
+    ret: &mut MaybeUninit<Value>,
+) {
+    // SAFETY: The `ptr` and `len` are provided by the JIT compiler and are guaranteed
+    // to form a valid UTF-8 string slice. The string data is embedded in the compiled
+    // code and has a static lifetime, ensuring the pointer is always valid.
+    unsafe {
+        ret.write(Value::String(
+            str::from_utf8_unchecked(slice::from_raw_parts(ptr, len)).to_owned(),
+        ));
+    }
+}
+
+/// Helper function to create a list value.
+///
+/// This function is called from JIT-compiled code to create list values
+/// from arrays of values.
+pub unsafe extern "C" fn helper_create_list(
+    ptr: *mut Value,
+    len: usize,
+    ret: &mut MaybeUninit<Value>,
+) {
+    // SAFETY: The `ptr` is allocated by the JIT compiler using `helper_alloc_array` and
+    // is guaranteed to be valid for `len` elements. The `Vec::from_raw_parts` call
+    // correctly takes ownership of the allocated memory, ensuring it is properly managed.
+    unsafe {
+        ret.write(Value::List(
+            List::from(Vec::from_raw_parts(ptr, len, len)).into(),
+        ));
+    }
+}
+
+/// Helper function to create an attribute set.
+///
+/// This function is called from JIT-compiled code to create a new, empty attribute set.
+pub unsafe extern "C" fn helper_create_attrs(
+    ret: &mut MaybeUninit<HashMap<String, Value>>,
+) {
+    ret.write(HashMap::new());
+}
+
+/// Helper function to add an attribute to an attribute set.
+///
+/// This function is called from JIT-compiled code to insert a key-value pair
+/// into an attribute set.
+pub unsafe extern "C" fn helper_push_attr(
+    attrs: &mut HashMap<SymId, Value>,
+    sym: SymId,
+    val: NonNull<Value>,
+) {
+    // SAFETY: The `sym_ptr` and `sym_len` are provided by the JIT compiler and are
+    // guaranteed to form a valid UTF-8 string slice. The `val` pointer is also
+    // guaranteed to be valid and non-null by the JIT compiler.
+    unsafe {
+        attrs.insert(
+            sym,
+            val.read(),
+        );
+    }
+}
+
+/// Helper function to finalize an attribute set.
+///
+/// This function is called from JIT-compiled code to convert a HashMap into
+/// a proper attribute set value.
+pub unsafe extern "C" fn helper_finalize_attrs(
+    attrs: NonNull<HashMap<String, Value>>,
+    ret: &mut MaybeUninit<Value>,
+) {
+    // SAFETY: The `attrs` pointer is guaranteed to be valid and non-null by the JIT
+    // compiler, which allocates it on the stack. The `read` operation correctly
+    // takes ownership of the HashMap.
+    ret.write(Value::AttrSet(
+        AttrSet::from(unsafe { attrs.read() }).into(),
+    ));
+}
+
+/// Helper function to enter a `with` expression scope.
+///
+/// This function is called from JIT-compiled code to enter a new `with` scope
+/// with the given namespace.
+pub unsafe extern "C" fn helper_enter_with<Ctx: JITContext>(
+    ctx: &mut Ctx,
+    namespace: NonNull<Value>,
+) {
+    // SAFETY: The `namespace` pointer is guaranteed to be valid and non-null by the JIT
+    // compiler. The `read` operation correctly takes ownership of the `Value`.
+    ctx.enter_with(unsafe { namespace.read() }.unwrap_attr_set().into_inner());
+}
+
+/// Helper function to exit a `with` expression scope.
+///
+/// This function is called from JIT-compiled code to exit the current `with` scope.
+pub unsafe extern "C" fn helper_exit_with<Ctx: JITContext>(ctx: &mut Ctx) {
+    ctx.exit_with();
+}
+
+/// Helper function to allocate an array of values.
+///
+/// This function is called from JIT-compiled code to allocate memory for
+/// arrays of values, such as function arguments or list elements.
+pub unsafe extern "C" fn helper_alloc_array(len: usize) -> *mut u8 {
+    // SAFETY: The `Layout` is guaranteed to be valid for non-zero `len`. The caller
+    // is responsible for deallocating the memory, which is typically done by
+    // `Vec::from_raw_parts` or `Box::from_raw` in other helpers.
+    unsafe { alloc(Layout::array::<Value>(len).unwrap()) }
+}
+
+/// Helper function for debugging.
+///
+/// This function is called from JIT-compiled code to print a value for debugging purposes.
+pub extern "C" fn helper_dbg(value: &Value) {
+    println!("{value:?}")
+}

evaluator/nixjit_jit/src/lib.rs

@@ -0,0 +1,740 @@
+//! The Just-In-Time (JIT) compilation module for nixjit.
+//!
+//! This module provides functionality to compile Low-Level IR (LIR) expressions
+//! into optimized machine code using Cranelift. The JIT compiler translates
+//! Nix expressions into efficient native code for faster evaluation.
+//!
+//! The main components are:
+//! - `JITCompiler`: The core compiler that manages the compilation process
+//! - `JITContext`: A trait that provides the execution context for JIT-compiled code
+//! - `Context`: An internal compilation context used during code generation
+
+use std::marker::PhantomData;
+use std::ops::Deref;
+use std::rc::Rc;
+
+use cranelift::codegen::ir::Function;
+use cranelift::codegen::ir::{self, ArgumentExtension, ArgumentPurpose, StackSlot};
+use cranelift::prelude::*;
+use cranelift_jit::{JITBuilder, JITModule};
+use cranelift_module::{FuncId, Linkage, Module};
+use hashbrown::{HashMap, HashSet};
+
+use nixjit_eval::{EvalContext, Value};
+use nixjit_ir::SymId;
+use nixjit_lir::Lir;
+
+mod compile;
+mod helpers;
+
+pub use compile::JITCompile;
+use helpers::*;
+
+/// A trait that provides the execution context for JIT-compiled code.
+///
+/// This trait extends `EvalContext` with additional methods needed
+/// for JIT compilation, such as managing `with` expression scopes directly.
+pub trait JITContext: EvalContext {
+    /// Enters a `with` expression scope with the given namespace.
+    fn enter_with(&mut self, namespace: Rc<HashMap<String, Value>>);
+    /// Exits the current `with` expression scope.
+    fn exit_with(&mut self);
+}
+
+/// Type alias for a JIT-compiled function.
+///
+/// This represents a function pointer to JIT-compiled code that takes
+/// a context pointer and a mutable value pointer as arguments.
+type F<Ctx> = unsafe extern "C" fn(*const Ctx, *mut Value);
+
+/// A JIT-compiled function.
+///
+/// This struct holds a function pointer to the compiled code and
+/// a set of strings that were used during compilation, which need
+/// to be kept alive for the function to work correctly.
+#[derive(Debug)]
+pub struct JITFunc<Ctx: JITContext> {
+    func: F<Ctx>,
+    strings: HashSet<String>,
+}
+
+impl<Ctx: JITContext> Deref for JITFunc<Ctx> {
+    type Target = F<Ctx>;
+    fn deref(&self) -> &Self::Target {
+        &self.func
+    }
+}
+
+/// The internal compilation context used during code generation.
+///
+/// This context holds references to the compiler, the Cranelift function builder,
+/// and manages resources like stack slots and string literals during compilation.
+struct Context<'comp, 'ctx, Ctx: JITContext> {
+    /// Reference to the JIT compiler.
+    pub compiler: &'comp mut JITCompiler<Ctx>,
+    /// The Cranelift function builder used to generate IR.
+    pub builder: FunctionBuilder<'ctx>,
+    /// Stack slots available for reuse.
+    free_slots: Vec<StackSlot>,
+    /// String literals used during compilation.
+    strings: HashSet<String>,
+}
+
+impl<'comp, 'ctx, Ctx: JITContext> Context<'comp, 'ctx, Ctx> {
+    fn new(compiler: &'comp mut JITCompiler<Ctx>, builder: FunctionBuilder<'ctx>) -> Self {
+        Self {
+            compiler,
+            builder,
+            free_slots: Vec::new(),
+            strings: HashSet::new(),
+        }
+    }
+
+    fn alloca(&mut self) -> StackSlot {
+        self.free_slots.pop().map_or_else(
+            || {
+                let slot = StackSlotData::new(StackSlotKind::ExplicitSlot, 32, 3);
+                self.builder.create_sized_stack_slot(slot)
+            },
+            |x| x,
+        )
+    }
+
+    fn free_slot(&mut self, slot: StackSlot) {
+        self.free_slots.push(slot);
+    }
+
+    fn alloc_array(&mut self, len: usize) -> ir::Value {
+        let len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, len as i64);
+        let alloc_array = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.alloc_array, self.builder.func);
+        let inst = self.builder.ins().call(alloc_array, &[len]);
+        self.builder.inst_results(inst)[0]
+    }
+
+    fn create_string(&mut self, string: &str) -> StackSlot {
+        let string = self
+            .strings
+            .get_or_insert_with(string, |_| string.to_owned());
+        let ptr = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, string.as_ptr() as i64);
+        let len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, string.len() as i64);
+        let create_string = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.create_string, self.builder.func);
+        let slot = self.alloca();
+        let ret = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(create_string, &[ptr, len, ret]);
+        slot
+    }
+
+    fn create_list(&mut self, ptr: ir::Value, len: usize) -> StackSlot {
+        let len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, len as i64);
+        let create_list = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.create_list, self.builder.func);
+        let slot = self.alloca();
+        let ret = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(create_list, &[ptr, len, ret]);
+        slot
+    }
+
+    fn create_attrs(&mut self) -> StackSlot {
+        let create_attrs = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.create_attrs, self.builder.func);
+        let slot = StackSlotData::new(StackSlotKind::ExplicitSlot, 40, 3);
+        let slot = self.builder.create_sized_stack_slot(slot);
+        let ret = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(create_attrs, &[ret]);
+        slot
+    }
+
+    fn push_attr(&mut self, attrs: StackSlot, sym: SymId, val: StackSlot) {
+        self.free_slot(attrs);
+        self.free_slot(val);
+        let attrs = self.builder.ins().stack_addr(types::I64, attrs, 0);
+        let val = self.builder.ins().stack_addr(types::I64, val, 0);
+        let sym = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, unsafe { sym.raw() } as i64);
+        let push_attr = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.push_attr, self.builder.func);
+        self.builder.ins().call(push_attr, &[attrs, sym, val]);
+    }
+
+    fn finalize_attrs(&mut self, attrs: StackSlot) -> StackSlot {
+        let attrs = self.builder.ins().stack_addr(types::I64, attrs, 0);
+        let finalize_attrs = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.finalize_attrs, self.builder.func);
+        let slot = self.alloca();
+        let ret = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(finalize_attrs, &[attrs, ret]);
+        slot
+    }
+
+    fn enter_with(&mut self, rt_ctx: ir::Value, namespace: StackSlot) {
+        let ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, namespace, 0);
+        let enter_with = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.enter_with, self.builder.func);
+        self.builder.ins().call(enter_with, &[rt_ctx, ptr]);
+    }
+
+    fn exit_with(&mut self, rt_ctx: ir::Value) {
+        let exit_with = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.exit_with, self.builder.func);
+        self.builder.ins().call(exit_with, &[rt_ctx]);
+    }
+
+    fn dbg(&mut self, slot: StackSlot) {
+        let ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        let dbg = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.dbg, self.builder.func);
+        self.builder.ins().call(dbg, &[ptr]);
+    }
+
+    fn call(&mut self, func: StackSlot, arg: StackSlot, call_ctx: ir::Value) {
+        let call = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.call, self.builder.func);
+        let func = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, func, 0);
+        let arg = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, arg, 0);
+        self.builder.ins().call(call, &[func, arg, call_ctx]);
+    }
+
+    fn lookup(&mut self, rt_ctx: ir::Value, sym: &str) -> StackSlot {
+        let sym = self.strings.get_or_insert_with(sym, |_| sym.to_owned());
+        let ptr = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, sym.as_ptr() as i64);
+        let len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, sym.len() as i64);
+        let lookup = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.lookup, self.builder.func);
+        let slot = self.alloca();
+        let ret = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(lookup, &[rt_ctx, ptr, len, ret]);
+        slot
+    }
+
+    fn lookup_arg(&mut self, ctx: ir::Value, idx: usize) -> StackSlot {
+        let slot = self.alloca();
+        let lookup_arg = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.lookup_arg, self.builder.func);
+        let idx = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, idx as i64);
+        let ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder.ins().call(lookup_arg, &[ctx, idx, ptr]);
+        slot
+    }
+
+    fn select(&mut self, slot: StackSlot, path_ptr: ir::Value, path_len: usize, ctx: ir::Value) {
+        let select = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.select, self.builder.func);
+        let path_len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, path_len as i64);
+        let ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        self.builder
+            .ins()
+            .call(select, &[ptr, path_ptr, path_len, ctx]);
+    }
+
+    fn select_with_default(
+        &mut self,
+        slot: StackSlot,
+        path_ptr: ir::Value,
+        path_len: usize,
+        default: StackSlot,
+        engine: ir::Value,
+        rt_ctx: ir::Value,
+    ) {
+        let select_with_default = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.select_with_default, self.builder.func);
+        let path_len = self
+            .builder
+            .ins()
+            .iconst(self.compiler.ptr_type, path_len as i64);
+        let ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, slot, 0);
+        let default_ptr = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, default, 0);
+        self.builder.ins().call(
+            select_with_default,
+            &[ptr, path_ptr, path_len, default_ptr, engine, rt_ctx],
+        );
+    }
+
+    pub fn eq(&mut self, lhs: StackSlot, rhs: StackSlot) {
+        let lhs = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, lhs, 0);
+        let rhs = self
+            .builder
+            .ins()
+            .stack_addr(self.compiler.ptr_type, rhs, 0);
+        let eq = self
+            .compiler
+            .module
+            .declare_func_in_func(self.compiler.eq, self.builder.func);
+        self.builder.ins().call(eq, &[lhs, rhs]);
+    }
+
+    pub fn get_tag(&mut self, slot: StackSlot) -> ir::Value {
+        self.builder.ins().stack_load(types::I64, slot, 0)
+    }
+
+    pub fn get_small_value(&mut self, ty: Type, slot: StackSlot) -> ir::Value {
+        self.builder.ins().stack_load(ty, slot, 8)
+    }
+}
+
+/// The main JIT compiler that manages the compilation process.
+pub struct JITCompiler<Ctx: JITContext> {
+    ctx: codegen::Context,
+    module: JITModule,
+    builder_ctx: Option<FunctionBuilderContext>,
+    _marker: PhantomData<Ctx>,
+
+    int_type: Type,
+    float_type: Type,
+    bool_type: Type,
+    ptr_type: Type,
+    value_type: Type,
+    func_sig: Signature,
+
+    call: FuncId,
+    lookup_arg: FuncId,
+    lookup: FuncId,
+    select: FuncId,
+    select_with_default: FuncId,
+
+    eq: FuncId,
+
+    alloc_array: FuncId,
+    create_string: FuncId,
+    create_list: FuncId,
+    create_attrs: FuncId,
+    push_attr: FuncId,
+    finalize_attrs: FuncId,
+    enter_with: FuncId,
+    exit_with: FuncId,
+    dbg: FuncId,
+}
+
+impl<Ctx: JITContext> Default for JITCompiler<Ctx> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<Ctx: JITContext> JITCompiler<Ctx> {
+    pub fn new() -> Self {
+        let mut flag_builder = settings::builder();
+        flag_builder.set("use_colocated_libcalls", "false").unwrap();
+        flag_builder.set("is_pic", "false").unwrap();
+        let isa_builder = cranelift_native::builder().unwrap_or_else(|msg| {
+            panic!("host machine is not supported: {msg}");
+        });
+        let isa = isa_builder
+            .finish(settings::Flags::new(flag_builder))
+            .unwrap();
+        let mut builder = JITBuilder::with_isa(isa, cranelift_module::default_libcall_names());
+
+        builder.symbol("helper_call", helper_call::<Ctx> as _);
+        builder.symbol("helper_lookup_arg", helper_lookup_arg::<Ctx> as _);
+        builder.symbol("helper_lookup", helper_lookup::<Ctx> as _);
+        builder.symbol("helper_select", helper_select::<Ctx> as _);
+        builder.symbol(
+            "helper_select_with_default",
+            helper_select_with_default::<Ctx> as _,
+        );
+        builder.symbol("helper_eq", helper_eq as _);
+
+        builder.symbol("helper_alloc_array", helper_alloc_array as _);
+        builder.symbol("helper_create_string", helper_create_string as _);
+        builder.symbol("helper_create_list", helper_create_list as _);
+        builder.symbol("helper_create_attrs", helper_create_attrs as _);
+        builder.symbol("helper_push_attr", helper_push_attr as _);
+        builder.symbol("helper_finalize_attrs", helper_finalize_attrs as _);
+        builder.symbol("helper_enter_with", helper_enter_with::<Ctx> as _);
+        builder.symbol("helper_exit_with", helper_exit_with::<Ctx> as _);
+        builder.symbol("helper_dbg", helper_dbg as _);
+
+        let mut module = JITModule::new(builder);
+        let ctx = module.make_context();
+
+        let int_type = types::I64;
+        let float_type = types::F64;
+        let bool_type = types::I8;
+        let ptr_type = module.target_config().pointer_type();
+        let value_type = types::I128;
+
+        let mut func_sig = module.make_signature();
+        func_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 2],
+        );
+
+        let mut call_sig = module.make_signature();
+        call_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 3],
+        );
+        let call = module
+            .declare_function("helper_call", Linkage::Import, &call_sig)
+            .unwrap();
+
+        let mut lookup_arg_sig = module.make_signature();
+        lookup_arg_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 3],
+        );
+        let lookup_arg = module
+            .declare_function("helper_lookup_arg", Linkage::Import, &lookup_arg_sig)
+            .unwrap();
+
+        let mut lookup_sig = module.make_signature();
+        lookup_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 4],
+        );
+        let lookup = module
+            .declare_function("helper_lookup", Linkage::Import, &lookup_sig)
+            .unwrap();
+
+        let mut select_sig = module.make_signature();
+        select_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 4],
+        );
+        let select = module
+            .declare_function("helper_select", Linkage::Import, &select_sig)
+            .unwrap();
+
+        let mut select_with_default_sig = module.make_signature();
+        select_with_default_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 6],
+        );
+        let select_with_default = module
+            .declare_function(
+                "helper_select_with_default",
+                Linkage::Import,
+                &select_with_default_sig,
+            )
+            .unwrap();
+
+        let mut eq_sig = module.make_signature();
+        eq_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 2],
+        );
+        let eq = module
+            .declare_function("helper_eq", Linkage::Import, &eq_sig)
+            .unwrap();
+
+        let mut alloc_array_sig = module.make_signature();
+        alloc_array_sig.params.push(AbiParam {
+            value_type: ptr_type,
+            purpose: ArgumentPurpose::Normal,
+            extension: ArgumentExtension::None,
+        });
+        alloc_array_sig.returns.push(AbiParam {
+            value_type: ptr_type,
+            purpose: ArgumentPurpose::Normal,
+            extension: ArgumentExtension::None,
+        });
+        let alloc_array = module
+            .declare_function("helper_alloc_array", Linkage::Import, &alloc_array_sig)
+            .unwrap();
+
+        let mut create_string_sig = module.make_signature();
+        create_string_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 3],
+        );
+        let create_string = module
+            .declare_function("helper_create_string", Linkage::Import, &create_string_sig)
+            .unwrap();
+
+        let mut create_list_sig = module.make_signature();
+        create_list_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 3],
+        );
+        let create_list = module
+            .declare_function("helper_create_list", Linkage::Import, &create_list_sig)
+            .unwrap();
+
+        let mut create_attrs_sig = module.make_signature();
+        create_attrs_sig.params.push(AbiParam {
+            value_type: ptr_type,
+            purpose: ArgumentPurpose::Normal,
+            extension: ArgumentExtension::None,
+        });
+        let create_attrs = module
+            .declare_function("helper_create_attrs", Linkage::Import, &create_attrs_sig)
+            .unwrap();
+
+        let mut push_attr_sig = module.make_signature();
+        push_attr_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 3],
+        );
+        let push_attr = module
+            .declare_function("helper_push_attr", Linkage::Import, &push_attr_sig)
+            .unwrap();
+
+        let mut finalize_attrs_sig = module.make_signature();
+        finalize_attrs_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 2],
+        );
+        let finalize_attrs = module
+            .declare_function(
+                "helper_finalize_attrs",
+                Linkage::Import,
+                &finalize_attrs_sig,
+            )
+            .unwrap();
+
+        let mut enter_with_sig = module.make_signature();
+        enter_with_sig.params.extend(
+            [AbiParam {
+                value_type: ptr_type,
+                purpose: ArgumentPurpose::Normal,
+                extension: ArgumentExtension::None,
+            }; 2],
+        );
+        let enter_with = module
+            .declare_function("helper_enter_with", Linkage::Import, &enter_with_sig)
+            .unwrap();
+
+        let mut exit_with_sig = module.make_signature();
+        exit_with_sig.params.push(AbiParam {
+            value_type: ptr_type,
+            purpose: ArgumentPurpose::Normal,
+            extension: ArgumentExtension::None,
+        });
+        let exit_with = module
+            .declare_function("helper_exit_with", Linkage::Import, &exit_with_sig)
+            .unwrap();
+
+        let mut dbg_sig = module.make_signature();
+        dbg_sig.params.push(AbiParam {
+            value_type: ptr_type,
+            purpose: ArgumentPurpose::Normal,
+            extension: ArgumentExtension::None,
+        });
+        let dbg = module
+            .declare_function("helper_dbg", Linkage::Import, &dbg_sig)
+            .unwrap();
+
+        Self {
+            builder_ctx: None,
+            _marker: PhantomData,
+            ctx,
+            module,
+
+            int_type,
+            float_type,
+            bool_type,
+            ptr_type,
+            value_type,
+            func_sig,
+
+            call,
+            lookup_arg,
+            lookup,
+            select,
+            select_with_default,
+
+            eq,
+
+            alloc_array,
+            create_string,
+            create_list,
+            create_attrs,
+            push_attr,
+            finalize_attrs,
+            enter_with,
+            exit_with,
+            dbg,
+        }
+    }
+
+    pub fn compile(&mut self, ir: &Lir, id: usize) -> JITFunc<Ctx> {
+        let func_id = self
+            .module
+            .declare_function(
+                format!("nixjit_thunk{id}").as_str(),
+                Linkage::Local,
+                &self.func_sig,
+            )
+            .unwrap();
+        let mut func = Function::new();
+        func.signature = self.func_sig.clone();
+        let mut builder_ctx = self.builder_ctx.take().unwrap_or_default();
+        let mut ctx = Context::new(self, FunctionBuilder::new(&mut func, &mut builder_ctx));
+
+        let entry = ctx.builder.create_block();
+        ctx.builder.append_block_params_for_function_params(entry);
+        ctx.builder.switch_to_block(entry);
+
+        let params = ctx.builder.block_params(entry);
+        let rt_ctx = params[0];
+        let ret = params[1];
+        let res = ir.compile(&mut ctx, rt_ctx);
+
+        let tag = ctx.builder.ins().stack_load(types::I64, res, 0);
+        let val0 = ctx.builder.ins().stack_load(types::I64, res, 8);
+        let val1 = ctx.builder.ins().stack_load(types::I64, res, 16);
+        let val2 = ctx.builder.ins().stack_load(types::I64, res, 24);
+        ctx.builder.ins().store(MemFlags::new(), tag, ret, 0);
+        ctx.builder.ins().store(MemFlags::new(), val0, ret, 8);
+        ctx.builder.ins().store(MemFlags::new(), val1, ret, 16);
+        ctx.builder.ins().store(MemFlags::new(), val2, ret, 24);
+        ctx.builder.ins().return_(&[]);
+        ctx.builder.seal_all_blocks();
+        ctx.builder.finalize();
+
+        let strings = ctx.strings;
+        if cfg!(debug_assertions) {
+            println!("{ir:#?}");
+            println!("{}", func.display());
+        }
+        self.ctx.func = func;
+        self.module.define_function(func_id, &mut self.ctx).unwrap();
+        self.module.finalize_definitions().unwrap();
+        self.ctx.clear();
+
+        let _ = self.builder_ctx.insert(builder_ctx);
+        // SAFETY: The `get_finalized_function` method returns a raw pointer to the
+        // compiled machine code. We transmute it to the correct function pointer type `F<Ctx>`.
+        // This is safe because the function was compiled with the signature defined in `self.func_sig`,
+        // which matches the signature of `F<Ctx>`. The lifetime of the compiled code is managed
+        // by the `JITModule`, ensuring the pointer remains valid.
+        unsafe {
+            JITFunc {
+                func: std::mem::transmute::<*const u8, F<Ctx>>(
+                    self.module.get_finalized_function(func_id),
+                ),
+                strings,
+            }
+        }
+    }
+}

evaluator/nixjit_lir/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "nixjit_lir"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+derive_more = { version = "2.0", features = ["full"] }
+hashbrown = "0.15"
+itertools = "0.14"
+rnix = "0.12"
+
+nixjit_error = { path = "../nixjit_error" }
+nixjit_ir = { path = "../nixjit_ir" }
+nixjit_hir = { path = "../nixjit_hir" }
+nixjit_macros = { path = "../nixjit_macros" }
+nixjit_value = { path = "../nixjit_value" }

evaluator/nixjit_lir/src/lib.rs

@@ -0,0 +1,315 @@
+//! The Low-level Intermediate Representation (LIR) for nixjit.
+//!
+//! This module defines the LIR, which is a more resolved and explicit representation
+//! than the HIR. The key transformation from HIR to LIR is the resolution of variable
+//! lookups. In the LIR, variable references are either resolved to a specific expression,
+//! a function argument, or are left as-is for dynamic lookup in a `with` environment.
+//!
+//! Key components:
+//! - `Lir`: An enum representing all LIR expression types, generated by the `ir!` macro.
+//! - `Resolve`: A trait for converting HIR nodes into LIR expressions.
+//! - `ResolveContext`: A trait providing the context for resolution, including scope
+//!   management and dependency tracking.
+
+use derive_more::{IsVariant, TryUnwrap, Unwrap};
+
+use hashbrown::HashMap;
+use nixjit_error::{Error, Result};
+use nixjit_hir as hir;
+use nixjit_ir::*;
+use nixjit_macros::ir;
+use nixjit_value::format_symbol;
+
+// The `ir!` macro generates the `Lir` enum and related structs and traits.
+ir! {
+    Lir,
+
+    AttrSet,
+    List,
+    HasAttr,
+    BinOp,
+    UnOp,
+    Select,
+    If,
+    Call,
+    With,
+    Assert,
+    ConcatStrings,
+    Const,
+    Str,
+    Var,
+    Path,
+    Arg(()),
+    PrimOp(PrimOpId),
+    ExprRef(ExprId),
+    StackRef(StackIdx),
+    FuncRef(ExprId),
+    Thunk(ExprId),
+}
+
+/// Represents the result of a variable lookup within the `ResolveContext`.
+#[derive(Debug)]
+pub enum LookupResult {
+    Stack(StackIdx),
+    /// The variable was found and resolved to a specific expression.
+    Expr(ExprId),
+    /// The variable could not be resolved statically, likely due to a `with` expression.
+    /// The lookup must be performed dynamically at evaluation time.
+    Unknown,
+    /// The variable was not found in any scope.
+    NotFound,
+}
+
+/// A context for the HIR-to-LIR resolution process.
+///
+/// This trait abstracts the environment in which expressions are resolved, managing
+/// scopes, dependencies, and the resolution of expressions themselves.
+pub trait ResolveContext {
+    /// Creates a new function, associating a parameter specification with a body expression.
+    fn new_func(&mut self, body: ExprId, param: Param);
+
+    /// Triggers the resolution of a given expression.
+    fn resolve(&mut self, expr: ExprId) -> Result<ExprId>;
+
+    /// Looks up a variable by name in the current scope.
+    fn lookup(&mut self, name: SymId) -> LookupResult;
+
+    fn get_sym(&self, id: SymId) -> &str;
+
+    fn lookup_arg(&mut self) -> ExprId;
+
+    /// Enters a `with` scope for the duration of a closure.
+    fn with_with_env(&mut self, f: impl FnOnce(&mut Self) -> Result<()>) -> Result<bool>;
+
+    /// Enters a `let` scope with a given set of bindings for the duration of a closure.
+    fn with_let_env<T>(
+        &mut self,
+        bindings: HashMap<SymId, ExprId>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T;
+
+    /// Enters a function parameter scope for the duration of a closure.
+    fn with_closure_env<T>(
+        &mut self,
+        func: ExprId,
+        arg: ExprId,
+        ident: Option<SymId>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T;
+}
+
+/// A trait for converting (resolving) an HIR node into an LIR expression.
+pub trait Resolve<Ctx: ResolveContext> {
+    /// Performs the resolution.
+    fn resolve(self, ctx: &mut Ctx) -> Result<Lir>;
+}
+
+/// The main entry point for resolving any HIR expression.
+impl<Ctx: ResolveContext> Resolve<Ctx> for hir::Hir {
+    fn resolve(self, ctx: &mut Ctx) -> Result<Lir> {
+        use hir::Hir::*;
+        match self {
+            AttrSet(x) => x.resolve(ctx),
+            List(x) => x.resolve(ctx),
+            HasAttr(x) => x.resolve(ctx),
+            BinOp(x) => x.resolve(ctx),
+            UnOp(x) => x.resolve(ctx),
+            Select(x) => x.resolve(ctx),
+            If(x) => x.resolve(ctx),
+            Func(x) => x.resolve(ctx),
+            Call(x) => x.resolve(ctx),
+            With(x) => x.resolve(ctx),
+            Assert(x) => x.resolve(ctx),
+            ConcatStrings(x) => x.resolve(ctx),
+            Const(x) => Ok(Lir::Const(x)),
+            Str(x) => Ok(Lir::Str(x)),
+            Var(x) => x.resolve(ctx),
+            Path(x) => x.resolve(ctx),
+            Let(x) => x.resolve(ctx),
+            Thunk(x) => ctx.resolve(x).map(Lir::Thunk),
+            Arg(_) => Ok(Lir::ExprRef(ctx.lookup_arg())),
+        }
+    }
+}
+
+/// Resolves an `AttrSet` by resolving all key and value expressions.
+impl<Ctx: ResolveContext> Resolve<Ctx> for AttrSet {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        for (_, v) in self.stcs.iter_mut() {
+            *v = ctx.resolve(*v)?;
+        }
+        for (k, _) in self.dyns.iter_mut() {
+            *k = ctx.resolve(*k)?;
+        }
+        for (_, v) in self.dyns.iter_mut() {
+            *v = ctx.resolve(*v)?;
+        }
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `List` by resolving each of its items.
+impl<Ctx: ResolveContext> Resolve<Ctx> for List {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        for item in self.items.iter_mut() {
+            *item = ctx.resolve(*item)?;
+        }
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `HasAttr` expression by resolving the LHS and any dynamic attributes in the path.
+impl<Ctx: ResolveContext> Resolve<Ctx> for HasAttr {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.lhs = ctx.resolve(self.lhs)?;
+        for attr in self.rhs.iter_mut() {
+            if let &mut Attr::Dynamic(expr) = attr {
+                *attr = ctx.resolve(expr).map(Attr::Dynamic)?
+            }
+        }
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `BinOp` by resolving its left and right hand sides.
+impl<Ctx: ResolveContext> Resolve<Ctx> for BinOp {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.lhs = ctx.resolve(self.lhs)?;
+        self.rhs = ctx.resolve(self.rhs)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `UnOp` by resolving its right hand side.
+impl<Ctx: ResolveContext> Resolve<Ctx> for UnOp {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.rhs = ctx.resolve(self.rhs)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `Select` by resolving the expression being selected from, any dynamic
+/// attributes in the path, and the default value if it exists.
+impl<Ctx: ResolveContext> Resolve<Ctx> for Select {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.expr = ctx.resolve(self.expr)?;
+        for attr in self.attrpath.iter_mut() {
+            if let &mut Attr::Dynamic(expr) = attr {
+                *attr = ctx.resolve(expr).map(Attr::Dynamic)?
+            }
+        }
+        if let Some(expr) = &mut self.default {
+            *expr = ctx.resolve(*expr)?;
+        }
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves an `If` expression by resolving the condition, consequence, and alternative.
+impl<Ctx: ResolveContext> Resolve<Ctx> for If {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.cond = ctx.resolve(self.cond)?;
+        self.consq = ctx.resolve(self.consq)?;
+        self.alter = ctx.resolve(self.alter)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `Func` by resolving its body within a new parameter scope.
+/// It then registers the function with the context.
+impl<Ctx: ResolveContext> Resolve<Ctx> for Func {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        ctx.with_closure_env(self.body, self.arg, self.param.ident, |ctx| {
+            self.body = ctx.resolve(self.body)?;
+            Ok(())
+        })?;
+        ctx.new_func(self.body, self.param);
+        Ok(Lir::FuncRef(self.body))
+    }
+}
+
+impl<Ctx: ResolveContext> Resolve<Ctx> for Call {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.func = ctx.resolve(self.func)?;
+        self.func = ctx.resolve(self.arg)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `With` expression by resolving the namespace and the body.
+/// The body is resolved within a special "with" scope.
+impl<Ctx: ResolveContext> Resolve<Ctx> for With {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.namespace = ctx.resolve(self.namespace)?;
+        let env_used = ctx.with_with_env(|ctx| {
+            self.expr = ctx.resolve(self.expr)?;
+            Ok(())
+        })?;
+        // Optimization: if the `with` environment was not actually used by any variable
+        // lookup in the body, we can elide the `With` node entirely.
+        if env_used {
+            Ok(self.to_lir())
+        } else {
+            Ok(Lir::ExprRef(self.expr))
+        }
+    }
+}
+
+/// Resolves an `Assert` by resolving the assertion condition and the body.
+impl<Ctx: ResolveContext> Resolve<Ctx> for Assert {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.assertion = ctx.resolve(self.assertion)?;
+        self.expr = ctx.resolve(self.expr)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `ConcatStrings` by resolving each part.
+impl<Ctx: ResolveContext> Resolve<Ctx> for ConcatStrings {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        for part in self.parts.iter_mut() {
+            *part = ctx.resolve(*part)?;
+        }
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `Var` by looking it up in the current context.
+impl<Ctx: ResolveContext> Resolve<Ctx> for Var {
+    fn resolve(self, ctx: &mut Ctx) -> Result<Lir> {
+        use LookupResult::*;
+        match ctx.lookup(self.sym) {
+            Expr(id) => Ok(Lir::ExprRef(id)),
+            Stack(idx) => Ok(Lir::StackRef(idx)),
+            Unknown => Ok(self.to_lir()),
+            NotFound => Err(Error::resolution_error(format!(
+                "undefined variable '{}'",
+                format_symbol(ctx.get_sym(self.sym))
+            ))),
+        }
+    }
+}
+
+/// Resolves a `Path` by resolving the underlying expression that defines the path's content.
+impl<Ctx: ResolveContext> Resolve<Ctx> for Path {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        self.expr = ctx.resolve(self.expr)?;
+        Ok(self.to_lir())
+    }
+}
+
+/// Resolves a `Let` expression by creating a new scope for the bindings, resolving
+/// the bindings and the body, and then returning a reference to the body.
+impl<Ctx: ResolveContext> Resolve<Ctx> for hir::Let {
+    fn resolve(mut self, ctx: &mut Ctx) -> Result<Lir> {
+        ctx.with_let_env(self.bindings.clone(), |ctx| {
+            for id in self.bindings.values_mut() {
+                *id = ctx.resolve(*id)?;
+            }
+            self.body = ctx.resolve(self.body)?;
+            Ok(())
+        })?;
+        // The `let` expression itself evaluates to its body.
+        Ok(Lir::ExprRef(self.body))
+    }
+}

evaluator/nixjit_macros/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "nixjit_macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+convert_case = "0.8"
+quote = "1.0"
+proc-macro2 = "1.0"
+syn = { version = "2.0", features = ["full"] }

evaluator/nixjit_macros/src/builtins.rs

@@ -0,0 +1,261 @@
+//! Implements the `#[builtins]` procedural macro attribute.
+//!
+//! This macro simplifies the process of defining built-in functions (primops)
+//! for the Nix interpreter. It inspects the functions inside a `mod` block
+//! and generates the necessary boilerplate to make them callable from Nix code.
+//!
+//! Specifically, it generates:
+//! 1. A `Builtins` struct containing arrays of constant values and function pointers.
+//! 2. A wrapper function for each user-defined function. This wrapper handles:
+//!    - Arity (argument count) checking.
+//!    - Type conversion from the generic `nixjit_eval::Value` into the
+//!      specific types expected by the user's function.
+//!    - Calling the user's function with the converted arguments.
+//!    - Wrapping the return value back into a `Result<nixjit_eval::Value>`.
+
+use convert_case::{Case, Casing};
+use proc_macro::TokenStream;
+use proc_macro2::Span;
+use quote::{ToTokens, format_ident, quote};
+use syn::{
+    FnArg, Item, ItemConst, ItemFn, ItemMod, Pat, PatIdent, PatType, Type, Visibility,
+    parse_macro_input,
+};
+
+/// The implementation of the `#[builtins]` macro.
+pub fn builtins_impl(input: TokenStream) -> TokenStream {
+    let item_mod = parse_macro_input!(input as ItemMod);
+    let mod_name = &item_mod.ident;
+    let visibility = &item_mod.vis;
+
+    let (_brace, items) = match item_mod.content {
+        Some(content) => content,
+        None => {
+            return syn::Error::new_spanned(
+                item_mod,
+                "`#[builtins]` macro can only be used on an inline module: `mod name { ... }`",
+            )
+            .to_compile_error()
+            .into();
+        }
+    };
+
+    let mut pub_item_mod = Vec::new();
+    let mut global = Vec::new();
+    let mut scoped = Vec::new();
+    let mut wrappers = Vec::new();
+
+    // Iterate over the items (functions, consts) in the user's module.
+    for item in &items {
+        match item {
+            Item::Const(item_const) => {
+                let (primop, wrapper) = match generate_const_wrapper(item_const) {
+                    Ok(result) => result,
+                    Err(e) => return e.to_compile_error().into(),
+                };
+                // Public functions are added to the global scope, private ones to a scoped set.
+                if matches!(item_const.vis, Visibility::Public(_)) {
+                    global.push(primop);
+                } else {
+                    scoped.push(primop);
+                }
+                wrappers.push(wrapper);
+            }
+            Item::Fn(item_fn) => {
+                // Handle function definitions. These become primops.
+                let (primop, wrapper) = match generate_primop_wrapper(item_fn) {
+                    Ok(result) => result,
+                    Err(e) => return e.to_compile_error().into(),
+                };
+                // Public functions are added to the global scope, private ones to a scoped set.
+                if matches!(item_fn.vis, Visibility::Public(_)) {
+                    global.push(primop);
+                    pub_item_mod.push(quote! { #item_fn });
+                } else {
+                    scoped.push(primop);
+                    pub_item_mod.push(
+                        quote! {
+                            pub #item_fn
+                        }
+                    );
+                }
+                wrappers.push(wrapper);
+            }
+            // Other items are passed through unchanged.
+            item => pub_item_mod.push(item.to_token_stream()),
+        }
+    }
+
+    let global_len = global.len();
+    let scoped_len = scoped.len();
+
+    // Assemble the final generated code.
+    let output = quote! {
+        // Re-create the user's module, now with generated wrappers.
+        #visibility mod #mod_name {
+            #(#pub_item_mod)*
+            #(#wrappers)*
+            pub const GLOBAL_LEN: usize = #global_len;
+            pub const SCOPED_LEN: usize = #scoped_len;
+        }
+
+        /// A struct containing all the built-in constants and functions.
+        pub struct Builtins<Ctx: BuiltinsContext> {
+            /// Global functions available in the global scope.
+            pub global: [(&'static str, usize, fn(&mut Ctx, ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value>); #mod_name::GLOBAL_LEN],
+            /// Scoped functions, typically available under the `builtins` attribute set.
+            pub scoped: [(&'static str, usize, fn(&mut Ctx, ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value>); #mod_name::SCOPED_LEN],
+        }
+
+        impl<Ctx: BuiltinsContext> Builtins<Ctx> {
+            /// Creates a new instance of the `Builtins` struct.
+            pub fn new() -> Self {
+                Self {
+                    global: [#(#global,)*],
+                    scoped: [#(#scoped,)*],
+                }
+            }
+        }
+    };
+
+    output.into()
+}
+
+fn generate_const_wrapper(
+    item_const: &ItemConst,
+) -> syn::Result<(proc_macro2::TokenStream, proc_macro2::TokenStream)> {
+    let const_name = &item_const.ident;
+    let const_val = &item_const.expr;
+    let name_str = const_name
+        .to_string()
+        .from_case(Case::UpperSnake)
+        .to_case(Case::Camel);
+    let const_name = format_ident!("{name_str}");
+    let wrapper_name = format_ident!("wrapper_{}", const_name);
+    let mod_name = format_ident!("builtins");
+
+    let fn_type = quote! { fn(&mut Ctx, ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value> };
+
+    // The primop metadata tuple: (name, arity, wrapper_function_pointer)
+    let primop = quote! { (#name_str, 0, #mod_name::#wrapper_name as #fn_type) };
+
+    // The generated wrapper function.
+    let wrapper = quote! {
+        pub fn #wrapper_name<Ctx: BuiltinsContext>(ctx: &mut Ctx, mut args: ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value> {
+            Ok(#const_val.into())
+        }
+    };
+
+    Ok((primop, wrapper))
+}
+/// Generates the primop metadata and the wrapper function for a single user-defined function.
+fn generate_primop_wrapper(
+    item_fn: &ItemFn,
+) -> syn::Result<(proc_macro2::TokenStream, proc_macro2::TokenStream)> {
+    let fn_name = &item_fn.sig.ident;
+    let name_str = fn_name
+        .to_string()
+        .from_case(Case::Snake)
+        .to_case(Case::Camel);
+    let wrapper_name = format_ident!("wrapper_{}", fn_name);
+    let mod_name = format_ident!("builtins");
+
+    let mut user_args = item_fn.sig.inputs.iter().peekable();
+
+    // Check if the first argument is a context `&mut Ctx`.
+    let has_ctx = if let Some(FnArg::Typed(first_arg)) = user_args.peek() {
+        if let (Type::Reference(_), Pat::Ident(PatIdent { ident, .. })) =
+            (&*first_arg.ty, &*first_arg.pat)
+        {
+            if ident == "ctx" {
+                user_args.next();
+                true
+            } else {
+                false
+            }
+        } else {
+            false
+        }
+    } else {
+        return Err(syn::Error::new_spanned(
+            fn_name,
+            "A builtin function must not have a receiver argument",
+        ));
+    };
+
+    // Collect the remaining arguments.
+    let arg_pats: Vec<_> = user_args.collect();
+    let arg_count = arg_pats.len();
+
+    let arg_unpacks = arg_pats.iter().enumerate().map(|(i, arg)| {
+        let arg_name = format_ident!("_arg{}", i, span = Span::call_site());
+        let arg_ty = match &arg {
+            FnArg::Typed(PatType { ty, .. }) => ty,
+            _ => unreachable!(),
+        };
+
+        quote! {
+            let #arg_name: #arg_ty = args.next().ok_or_else(|| ::nixjit_error::Error::eval_error("Not enough arguments provided".to_string()))?
+                .try_into().map_err(|e| ::nixjit_error::Error::eval_error(format!("Argument type conversion failed: {}", e)))?;
+        }
+    });
+
+    // Get the names of the arguments to pass to the user's function.
+    let arg_names: Vec<_> = arg_pats
+        .iter()
+        .enumerate()
+        .map(|(i, arg)| match &arg {
+            FnArg::Typed(PatType { .. }) => {
+                format_ident!("_arg{}", i, span = Span::call_site())
+            }
+            _ => unreachable!(),
+        })
+        .collect();
+
+    // Construct the argument list for the final call.
+    let mut call_args = quote! { #(#arg_names),* };
+    if has_ctx {
+        call_args = quote! { ctx, #(#arg_names),* };
+    }
+
+    // Check if the user's function already returns a `Result`.
+    let returns_result = match &item_fn.sig.output {
+        syn::ReturnType::Type(_, ty) => {
+            if let Type::Path(type_path) = &**ty {
+                type_path.path.segments.iter().any(|s| s.ident == "Result")
+            } else {
+                false
+            }
+        }
+        _ => false,
+    };
+
+    // Wrap the call expression in `Ok(...)` if it doesn't return a `Result`.
+    let call_expr = if returns_result {
+        quote! { #fn_name(#call_args) }
+    } else {
+        quote! { Ok(#fn_name(#call_args).into()) }
+    };
+
+    let arity = arg_names.len();
+    let fn_type = quote! { fn(&mut Ctx, ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value> };
+
+    // The primop metadata tuple: (name, arity, wrapper_function_pointer)
+    let primop = quote! { (#name_str, #arity, #mod_name::#wrapper_name as #fn_type) };
+
+    // The generated wrapper function.
+    let wrapper = quote! {
+        pub fn #wrapper_name<Ctx: BuiltinsContext>(ctx: &mut Ctx, mut args: ::nixjit_eval::Args) -> ::nixjit_error::Result<::nixjit_eval::Value> {
+            if args.len() != #arg_count {
+                return Err(::nixjit_error::Error::eval_error(format!("Function '{}' expects {} arguments, but received {}", #name_str, #arg_count, args.len())));
+            }
+
+            let mut args = args.into_iter();
+            #(#arg_unpacks)*
+
+            #call_expr
+        }
+    };
+
+    Ok((primop, wrapper))
+}

evaluator/nixjit_macros/src/ir.rs

@@ -0,0 +1,203 @@
+//! Implements the `ir!` procedural macro.
+//!
+//! This macro is designed to reduce the boilerplate associated with defining
+//! an Intermediate Representation (IR) that follows a specific pattern. It generates:
+//! 1. An enum representing the different kinds of IR nodes (e.g., `Hir`, `Lir`).
+//! 2. Structs for each of the variants that have fields.
+//! 3. `Ref` and `Mut` versions of the main enum for ergonomic pattern matching on references.
+//! 4. `From` implementations to easily convert from a struct variant (e.g., `BinOp`) to the main enum (`Hir::BinOp`).
+//! 5. A `To[IrName]` trait to provide a convenient `.to_hir()` or `.to_lir()` method on the variant structs.
+
+use convert_case::{Case, Casing};
+use proc_macro::TokenStream;
+use quote::{format_ident, quote};
+use syn::{
+    FieldsNamed, Ident, Token, Type, parenthesized,
+    parse::{Parse, ParseStream, Result},
+    punctuated::Punctuated,
+    token,
+};
+
+/// Represents one of the variants passed to the `ir!` macro.
+pub enum VariantInput {
+    /// A unit-like variant, e.g., `Arg`.
+    Unit(Ident),
+    /// A tuple-like variant with one unnamed field, e.g., `ExprRef(ExprId)`.
+    Tuple(Ident, Type),
+    /// A struct-like variant with named fields, e.g., `BinOp { lhs: ExprId, rhs: ExprId, kind: BinOpKind }`.
+    Struct(Ident, FieldsNamed),
+}
+
+/// The top-level input for the `ir!` macro.
+pub struct MacroInput {
+    /// The name of the main IR enum to be generated (e.g., `Hir`).
+    pub base_name: Ident,
+    /// The list of variants for the enum.
+    pub variants: Punctuated<VariantInput, Token![,]>,
+}
+
+impl Parse for VariantInput {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let name: Ident = input.parse()?;
+
+        if input.peek(token::Paren) {
+            // Parse a tuple-like variant: `Variant(Type)`
+            let content;
+            parenthesized!(content in input);
+            let ty: Type = content.parse()?;
+
+            if !content.is_empty() {
+                return Err(content.error("Expected a single type inside parentheses"));
+            }
+
+            Ok(VariantInput::Tuple(name, ty))
+        } else if input.peek(token::Brace) {
+            // Parse a struct-like variant: `Variant { field: Type, ... }`
+            let fields: FieldsNamed = input.parse()?;
+            Ok(VariantInput::Struct(name, fields))
+        } else {
+            // Parse a unit-like variant: `Variant`
+            Ok(VariantInput::Unit(name))
+        }
+    }
+}
+
+impl Parse for MacroInput {
+    fn parse(input: ParseStream) -> Result<Self> {
+        // The macro input is expected to be: `IrName, Variant1, Variant2, ...`
+        let base_name = input.parse()?;
+        input.parse::<Token![,]>()?;
+        let variants = Punctuated::parse_terminated(input)?;
+
+        Ok(MacroInput {
+            base_name,
+            variants,
+        })
+    }
+}
+
+/// The implementation of the `ir!` macro.
+pub fn ir_impl(input: TokenStream) -> TokenStream {
+    let parsed_input = syn::parse_macro_input!(input as MacroInput);
+
+    let base_name = &parsed_input.base_name;
+    let ref_name = format_ident!("{}Ref", base_name);
+    let mut_name = format_ident!("{}Mut", base_name);
+    let to_trait_name = format_ident!("To{}", base_name);
+    let to_trait_fn_name = format_ident!("to_{}", base_name.to_string().to_case(Case::Snake));
+
+    let mut enum_variants = Vec::new();
+    let mut struct_defs = Vec::new();
+    let mut ref_variants = Vec::new();
+    let mut mut_variants = Vec::new();
+    let mut as_ref_arms = Vec::new();
+    let mut as_mut_arms = Vec::new();
+    let mut from_impls = Vec::new();
+    let mut to_trait_impls = Vec::new();
+
+    for variant in parsed_input.variants {
+        match variant {
+            VariantInput::Unit(name) => {
+                let inner_type = name.clone();
+                enum_variants.push(quote! { #name(#inner_type) });
+                ref_variants.push(quote! { #name(&'a #inner_type) });
+                mut_variants.push(quote! { #name(&'a mut #inner_type) });
+                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
+                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
+                from_impls.push(quote! {
+                    impl From<#inner_type> for #base_name {
+                        fn from(val: #inner_type) -> Self { #base_name::#name(val) }
+                    }
+                });
+                to_trait_impls.push(quote! {
+                    impl #to_trait_name for #name {
+                        fn #to_trait_fn_name(self) -> #base_name { #base_name::from(self) }
+                    }
+                });
+            }
+            VariantInput::Tuple(name, ty) => {
+                enum_variants.push(quote! { #name(#ty) });
+                ref_variants.push(quote! { #name(&'a #ty) });
+                mut_variants.push(quote! { #name(&'a mut #ty) });
+                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
+                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
+            }
+            VariantInput::Struct(name, fields) => {
+                let inner_type = name.clone();
+                struct_defs.push(quote! {
+                    #[derive(Debug)]
+                    pub struct #name #fields
+                });
+                enum_variants.push(quote! { #name(#inner_type) });
+                ref_variants.push(quote! { #name(&'a #inner_type) });
+                mut_variants.push(quote! { #name(&'a mut #inner_type) });
+                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
+                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
+                from_impls.push(quote! {
+                    impl From<#inner_type> for #base_name {
+                        fn from(val: #inner_type) -> Self { #base_name::#name(val) }
+                    }
+                });
+                to_trait_impls.push(quote! {
+                    impl #to_trait_name for #name {
+                        fn #to_trait_fn_name(self) -> #base_name { #base_name::from(self) }
+                    }
+                });
+            }
+        }
+    }
+
+    // Assemble the final generated code.
+    let expanded = quote! {
+        /// The main IR enum, generated by the `ir!` macro.
+        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
+        pub enum #base_name {
+            #( #enum_variants ),*
+        }
+
+        // The struct definitions for the enum variants.
+        #( #struct_defs )*
+
+        /// An immutable reference version of the IR enum.
+        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
+        pub enum #ref_name<'a> {
+            #( #ref_variants ),*
+        }
+
+        /// A mutable reference version of the IR enum.
+        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
+        pub enum #mut_name<'a> {
+            #( #mut_variants ),*
+        }
+
+        impl #base_name {
+            /// Converts a `&Ir` into a `IrRef`.
+            pub fn as_ref(&self) -> #ref_name<'_> {
+                match self {
+                    #( #as_ref_arms ),*
+                }
+            }
+
+            /// Converts a `&mut Ir` into a `IrMut`.
+            pub fn as_mut(&mut self) -> #mut_name<'_> {
+                match self {
+                    #( #as_mut_arms ),*
+                }
+            }
+        }
+
+        // `From` implementations for converting variant structs into the main enum.
+        #( #from_impls )*
+
+        /// A trait for converting a variant struct into the main IR enum.
+        pub trait #to_trait_name {
+            /// Performs the conversion.
+            fn #to_trait_fn_name(self) -> #base_name;
+        }
+
+        // Implement the `ToIr` trait for each variant struct.
+        #( #to_trait_impls )*
+    };
+
+    TokenStream::from(expanded)
+}

evaluator/nixjit_macros/src/lib.rs

@@ -0,0 +1,23 @@
+//! This crate provides procedural macros for the nixjit project.
+use proc_macro::TokenStream;
+
+mod builtins;
+mod ir;
+
+/// A procedural macro to reduce boilerplate when defining an Intermediate Representation (IR).
+///
+/// It generates an enum for the IR, along with `Ref` and `Mut` variants,
+/// `From` implementations, and a `ToHir` or `ToLir` trait.
+#[proc_macro]
+pub fn ir(input: TokenStream) -> TokenStream {
+    ir::ir_impl(input)
+}
+
+/// A procedural macro attribute to simplify the definition of built-in functions.
+///
+/// It generates the necessary boilerplate to wrap functions and expose them
+/// to the evaluation engine, handling argument type conversions and arity checking.
+#[proc_macro_attribute]
+pub fn builtins(_attr: TokenStream, input: TokenStream) -> TokenStream {
+    builtins::builtins_impl(input)
+}

evaluator/nixjit_value/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "nixjit_value"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+derive_more = { version = "2.0", features = ["full"] }
+regex = "1.11"

evaluator/nixjit_value/src/lib.rs

@@ -0,0 +1,217 @@
+//! Defines the public-facing data structures for Nix values.
+//!
+//! These types are used to represent the final result of an evaluation and are
+//! designed to be user-friendly and serializable. They are distinct from the
+//! internal `Value` types used during evaluation in `nixjit_eval`.
+
+use core::fmt::{Debug, Display, Formatter, Result as FmtResult};
+use core::hash::Hash;
+use core::ops::Deref;
+
+use std::borrow::Cow;
+use std::collections::BTreeMap;
+use std::sync::LazyLock;
+
+use derive_more::{Constructor, IsVariant, Unwrap};
+use regex::Regex;
+
+/// Represents a constant, primitive value in Nix.
+#[derive(Debug, Clone, Copy, PartialEq, IsVariant, Unwrap)]
+pub enum Const {
+    /// A boolean value (`true` or `false`).
+    Bool(bool),
+    /// A 64-bit signed integer.
+    Int(i64),
+    /// A 64-bit floating-point number.
+    Float(f64),
+    /// The `null` value.
+    Null,
+}
+
+impl Display for Const {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        use Const::*;
+        match self {
+            Int(x) => write!(f, "{x}"),
+            Float(x) => write!(f, "{x}"),
+            Bool(x) => write!(f, "{x}"),
+            Null => write!(f, "null"),
+        }
+    }
+}
+
+impl From<bool> for Const {
+    fn from(value: bool) -> Self {
+        Const::Bool(value)
+    }
+}
+
+impl From<i64> for Const {
+    fn from(value: i64) -> Self {
+        Const::Int(value)
+    }
+}
+
+impl From<f64> for Const {
+    fn from(value: f64) -> Self {
+        Const::Float(value)
+    }
+}
+
+/// Represents a Nix symbol, which is used as a key in attribute sets.
+#[derive(Debug, Clone, Hash, PartialEq, Eq, PartialOrd, Ord, Constructor)]
+pub struct Symbol(String);
+
+impl<T: Into<String>> From<T> for Symbol {
+    fn from(value: T) -> Self {
+        Symbol(value.into())
+    }
+}
+
+/// Formats a string slice as a Nix symbol, quoting it if necessary.
+pub fn format_symbol<'a>(sym: impl Into<Cow<'a, str>>) -> Cow<'a, str> {
+    let sym = sym.into();
+    if REGEX.is_match(&sym) {
+        sym
+    } else {
+        Cow::Owned(format!(r#""{sym}""#))
+    }
+}
+
+impl Display for Symbol {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        if self.normal() {
+            write!(f, "{}", self.0)
+        } else {
+            write!(f, r#""{}""#, self.0)
+        }
+    }
+}
+
+static REGEX: LazyLock<Regex> =
+    LazyLock::new(|| Regex::new(r"^[a-zA-Z_][a-zA-Z0-9_'-]*$").unwrap());
+impl Symbol {
+    /// Checks if the symbol is a "normal" identifier that doesn't require quotes.
+    fn normal(&self) -> bool {
+        REGEX.is_match(self)
+    }
+}
+
+impl Deref for Symbol {
+    type Target = str;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Symbol {
+    /// Consumes the `Symbol`, returning its inner `String`.
+    pub fn into_inner(self) -> String {
+        self.0
+    }
+
+    /// Returns a reference to the inner `String`.
+    pub fn as_inner(&self) -> &String {
+        &self.0
+    }
+}
+
+/// Represents a Nix attribute set, which is a map from symbols to values.
+#[derive(Constructor, Clone, PartialEq)]
+pub struct AttrSet {
+    data: BTreeMap<Symbol, Value>,
+}
+
+impl Debug for AttrSet {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        use Value::*;
+        write!(f, "{{")?;
+        for (k, v) in self.data.iter() {
+            write!(f, " {k:?} = ")?;
+            match v {
+                List(_) => write!(f, "[ ... ];")?,
+                AttrSet(_) => write!(f, "{{ ... }};")?,
+                v => write!(f, "{v:?};")?,
+            }
+        }
+        write!(f, " }}")
+    }
+}
+
+impl Display for AttrSet {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        use Value::*;
+        write!(f, "{{ ")?;
+        let mut first = true;
+        for (k, v) in self.data.iter() {
+            if !first {
+                write!(f, "; ")?;
+            }
+            write!(f, "{k} = ")?;
+            match v {
+                AttrSet(_) => write!(f, "{{ ... }}"),
+                List(_) => write!(f, "[ ... ]"),
+                v => write!(f, "{v}"),
+            }?;
+            first = false;
+        }
+        write!(f, " }}")
+    }
+}
+
+/// Represents a Nix list, which is a vector of values.
+#[derive(Constructor, Clone, Debug, PartialEq)]
+pub struct List {
+    data: Vec<Value>,
+}
+
+impl Display for List {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        write!(f, "[ ")?;
+        for v in self.data.iter() {
+            write!(f, "{v} ")?;
+        }
+        write!(f, "]")
+    }
+}
+
+/// Represents any possible Nix value that can be returned from an evaluation.
+#[derive(IsVariant, Unwrap, Clone, Debug, PartialEq)]
+pub enum Value {
+    /// A constant value (int, float, bool, null).
+    Const(Const),
+    /// A string value.
+    String(String),
+    /// An attribute set.
+    AttrSet(AttrSet),
+    /// A list.
+    List(List),
+    /// A thunk, representing a delayed computation.
+    Thunk,
+    /// A function (lambda).
+    Func,
+    /// A primitive (built-in) operation.
+    PrimOp,
+    /// A partially applied primitive operation.
+    PrimOpApp,
+    /// A marker for a value that has been seen before during serialization, to break cycles.
+    /// This is used to prevent infinite recursion when printing or serializing cyclic data structures.
+    Repeated,
+}
+
+impl Display for Value {
+    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
+        use Value::*;
+        match self {
+            Const(x) => write!(f, "{x}"),
+            String(x) => write!(f, r#""{x}""#),
+            AttrSet(x) => write!(f, "{x}"),
+            List(x) => write!(f, "{x}"),
+            Thunk => write!(f, "<CODE>"),
+            Func => write!(f, "<LAMBDA>"),
+            PrimOp => write!(f, "<PRIMOP>"),
+            PrimOpApp => write!(f, "<PRIMOP-APP>"),
+            Repeated => write!(f, "<REPEATED>"),
+        }
+    }
+}

flake.lock

@@ -8,11 +8,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1746167999,
+        "lastModified": 1754894611,
-        "narHash": "sha256-18XGHsjk/5H8F0OGUCG56CeeW1u6qQ7tAfQK3azlwWg=",
+        "narHash": "sha256-TEyTVDhzFyfvPahhi1iAmkopt6fMiTlmn6f278lTdDs=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "bcbc23a4f3391c1c3657f1847cb693aaea3aed76",
+        "rev": "a01861ebeb4d9c504845e7fb81509b82333ca0aa",
         "type": "github"
       },
       "original": {
@@ -23,11 +23,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1746141548,
+        "lastModified": 1754725699,
-        "narHash": "sha256-IgBWhX7A2oJmZFIrpRuMnw5RAufVnfvOgHWgIdds+hc=",
+        "narHash": "sha256-iAcj9T/Y+3DBy2J0N+yF9XQQQ8IEb5swLFzs23CdP88=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "f02fddb8acef29a8b32f10a335d44828d7825b78",
+        "rev": "85dbfc7aaf52ecb755f87e577ddbe6dbbdbc1054",
         "type": "github"
       },
       "original": {
@@ -46,11 +46,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1746093169,
+        "lastModified": 1754834452,
-        "narHash": "sha256-3gmUmzIzfzlgF/b4HXvtoBIP4bKofVeEubX7LcPBYLo=",
+        "narHash": "sha256-otzv/l7c1rL+eH1cuJnUZVp4DR2dMdEIfhtLxTelIBY=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "298fa81aacda7b06de4db55c377b1aa081906bc9",
+        "rev": "4e147e787987fdb1baf081bd5c60bedfb0aabe16",
         "type": "github"
       },
       "original": {

flake.nix

@@ -10,11 +10,10 @@
     in
     {
       devShells = forAllSystems (system:
-        let pkgs = import nixpkgs { inherit system; }; in
+        let pkgs = import nixpkgs { inherit system; config.allowUnfree = true; }; in
         {
           default = pkgs.mkShell {
             packages = with pkgs; [
-              zsh
               (fenix.packages.${system}.complete.withComponents [
                 "cargo"
                 "clippy"
@@ -24,24 +23,11 @@
                 "rust-analyzer"
                 "miri"
               ])
-              llvm_18
+              lldb
-              libffi
+              valgrind
-              libxml2
+              gemini-cli
-              ncurses
+              claude-code
             ];
-            LLVM_SYS_181_PREFIX = toString pkgs.llvm_18.dev;
-            LD_LIBRARY_PATH = let
-              libs = with pkgs; [
-                llvm_18.lib
-                stdenv.cc.cc.lib
-                libffi
-                libxml2
-                ncurses
-                libz
-              ];
-              in
-                builtins.concatStringsSep ":" (map (lib: "${lib}/lib") libs)
-              ;
           };
         }
       );

src/bin/repl.rs

@@ -1,65 +0,0 @@
-use inkwell::context::Context;
-use itertools::Itertools;
-use rustyline::error::ReadlineError;
-use rustyline::{DefaultEditor, Result};
-
-use nixjit::compile::compile;
-use nixjit::error::Error;
-use nixjit::ir::downgrade;
-use nixjit::vm::{JITContext, run};
-
-macro_rules! unwrap {
-    ($e:expr) => {
-        match $e {
-            Ok(ok) => ok,
-            Err(err) => {
-                println!("{err}");
-                continue;
-            }
-        }
-    };
-}
-
-fn main() -> Result<()> {
-    let mut rl = DefaultEditor::new()?;
-    loop {
-        let readline = rl.readline("nixjit-repl> ");
-        match readline {
-            Ok(expr) => {
-                if expr.trim().is_empty() {
-                    continue;
-                }
-                rl.add_history_entry(expr.as_str())?;
-                let root = rnix::Root::parse(&expr);
-                if !root.errors().is_empty() {
-                    println!(
-                        "{}",
-                        Error::ParseError(
-                            root.errors().iter().map(|err| err.to_string()).join(";")
-                        )
-                    );
-                    continue;
-                }
-                let expr = root.tree().expr().unwrap();
-                let downgraded = unwrap!(downgrade(expr));
-                let prog = compile(downgraded);
-                let ctx = Context::create();
-                let jit = JITContext::new(&ctx);
-                println!("{}", unwrap!(run(prog, jit)));
-            }
-            Err(ReadlineError::Interrupted) => {
-                println!("CTRL-C");
-                break;
-            }
-            Err(ReadlineError::Eof) => {
-                println!("CTRL-D");
-                break;
-            }
-            Err(err) => {
-                println!("Error: {err:?}");
-                break;
-            }
-        }
-    }
-    Ok(())
-}

src/builtins/mod.rs

@@ -1,60 +0,0 @@
-use hashbrown::HashMap;
-use std::rc::Rc;
-
-use crate::ty::internal::{AttrSet, Const, PrimOp, Value};
-use crate::vm::{Env, VM};
-
-pub fn env<'vm>(vm: &'vm VM) -> Env<'vm> {
-    let mut env = Env::empty();
-    env.insert(vm.new_sym("true"), Value::Const(Const::Bool(true)));
-    env.insert(vm.new_sym("false"), Value::Const(Const::Bool(false)));
-
-    let primops = [
-        PrimOp::new("add", 2, |_, args| {
-            let [first, second]: [Value; 2] = args.try_into().unwrap();
-            first.add(second).ok()
-        }),
-        PrimOp::new("sub", 2, |_, args| {
-            let [first, second]: [Value; 2] = args.try_into().unwrap();
-            first.add(second.neg()).ok()
-        }),
-        PrimOp::new("mul", 2, |_, args| {
-            let [first, second]: [Value; 2] = args.try_into().unwrap();
-            first.mul(second).ok()
-        }),
-        PrimOp::new("div", 2, |_, args| {
-            let [first, second]: [Value; 2] = args.try_into().unwrap();
-            first.div(second)
-        }),
-        PrimOp::new("lessThan", 2, |_, args| {
-            let [first, second]: [Value; 2] = args.try_into().unwrap();
-            first.lt(second).ok()
-        }),
-        PrimOp::new("seq", 2, |vm, args| {
-            let [mut first, second]: [Value; 2] = args.try_into().unwrap();
-            first.force(vm).unwrap();
-            second.ok()
-        }),
-        PrimOp::new("deepSeq", 2, |vm, args| {
-            let [mut first, second]: [Value; 2] = args.try_into().unwrap();
-            first.force_deep(vm).unwrap();
-            second.ok()
-        }),
-    ];
-
-    let mut map = HashMap::new();
-    for primop in primops {
-        let primop = Rc::new(primop);
-        env.insert(
-            vm.new_sym(format!("__{}", primop.name)),
-            Value::PrimOp(primop.clone()),
-        );
-        map.insert(vm.new_sym(primop.name), Value::PrimOp(primop));
-    }
-    let attrs: Rc<_> = AttrSet::from_inner(map).into();
-    let mut builtins = Value::AttrSet(attrs);
-    builtins.push_attr(vm.new_sym("builtins"), Value::Builtins);
-
-    env.insert(vm.new_sym("builtins"), builtins);
-    env
-}

src/bytecode.rs

@@ -1,118 +0,0 @@
-use hashbrown::HashMap;
-
-use ecow::EcoString;
-
-use crate::ty::internal::{Const, Param};
-
-type Slice<T> = Box<[T]>;
-
-pub type OpCodes = Slice<OpCode>;
-
-#[derive(Debug, Clone, Copy)]
-pub enum OpCode {
-    /// load a constant onto stack
-    Const { idx: usize },
-    /// load a dynamic var onto stack
-    LookUp { sym: usize },
-    /// load a thunk lazily onto stack
-    LoadThunk { idx: usize },
-    /// let TOS capture current environment
-    CaptureEnv,
-    /// force TOS to value
-    ForceValue,
-
-    /// [ .. func args @ .. ] consume (`arity` + 1) elements, call `func` with args` of length `arity`
-    /// Example: __add 1 2 => [ LookUp("__add") Const(1) Const(2) Call(2) ]
-    Call { arity: usize },
-    /// make a function
-    Func { idx: usize },
-
-    /// consume 1 element, assert TOS is true
-    Assert,
-
-    /// jump forward
-    Jmp { step: usize },
-    /// [ .. cond ] consume 1 element, if `cond`` is true, then jump forward
-    JmpIfTrue { step: usize },
-    /// [ .. cond ] consume 1 element, if `cond` is false, then jump forward
-    JmpIfFalse { step: usize },
-
-    /// push an empty attribute set onto stack
-    AttrSet { cap: usize },
-    /// finalize the recursive attribute set at TOS
-    FinalizeRec,
-    /// [ .. set value ] consume 1 element, push a static kv pair (`name`, `value`) into `set`
-    PushStaticAttr { name: usize },
-    /// [ .. set name value ] consume 2 elements, push a dynamic kv pair (`name`, `value`) in to `set`
-    PushDynamicAttr,
-
-    /// push an empty list onto stack
-    List,
-    /// [ .. list elem ] consume 1 element, push `elem` into `list`
-    PushElem,
-
-    /// convert the string as TOS to a path
-    Path,
-
-    /// [ .. a b ] consume 2 elements, perform a string concatenation `a` + `b`
-    ConcatString,
-    /// [ .. a b ] consume 2 elements, perform a binary operation `a` `op` `b`
-    BinOp { op: BinOp },
-    /// [ .. a ] consume 1 element, perform a unary operation `op` `a`
-    UnOp { op: UnOp },
-    /// set TOS to the bool value of whether TOS contains `sym`
-    HasAttr { sym: usize },
-    /// [ .. set sym ] consume 2 elements, set TOS to the bool value of whether `set` contains `sym`
-    HasDynamicAttr,
-    /// [ .. set ] select `sym` from `set`
-    Select { sym: usize },
-    /// [ .. set default ] select `sym` from `set` or `default`
-    SelectOrDefault { sym: usize },
-    /// [ .. set sym ] select `sym` from `set`
-    SelectDynamic,
-    /// [ .. set sym default ] select `sym` from `set` or `default`
-    SelectDynamicOrDefault,
-    /// enter the environment of the attribute set at TOS
-    EnterEnv,
-    /// exit current envrironment
-    LeaveEnv,
-
-    /// illegal operation, used as termporary placeholder
-    Illegal,
-}
-
-#[derive(Debug, Clone, Copy)]
-pub enum BinOp {
-    Add,
-    Sub,
-    Mul,
-    Div,
-    And,
-    Or,
-    Eq,
-    Lt,
-    Con,
-    Upd,
-}
-
-#[derive(Debug, Clone, Copy)]
-pub enum UnOp {
-    Neg,
-    Not,
-}
-
-#[derive(Debug)]
-pub struct Func {
-    pub param: Param,
-    pub opcodes: OpCodes,
-}
-
-#[derive(Debug)]
-pub struct Program {
-    pub top_level: OpCodes,
-    pub thunks: Slice<OpCodes>,
-    pub funcs: Slice<Func>,
-    pub symbols: Vec<EcoString>,
-    pub symmap: HashMap<EcoString, usize>,
-    pub consts: Box<[Const]>,
-}

src/compile.rs

@@ -1,410 +0,0 @@
-use crate::bytecode::*;
-use crate::ir;
-
-pub struct Compiler {
-    opcodes: Vec<OpCode>,
-}
-
-pub fn compile(downgraded: ir::Downgraded) -> Program {
-    Program {
-        top_level: Compiler::new().compile(downgraded.top_level),
-        thunks: downgraded
-            .thunks
-            .into_iter()
-            .map(|thunk| Compiler::new().compile(thunk))
-            .collect(),
-        funcs: downgraded
-            .funcs
-            .into_iter()
-            .map(|func| Func {
-                param: func.param.into(),
-                opcodes: Compiler::new().compile(*func.body),
-            })
-            .collect(),
-        symbols: downgraded.symbols,
-        symmap: downgraded.symmap,
-        consts: downgraded.consts,
-    }
-}
-
-impl Compiler {
-    fn new() -> Self {
-        Self {
-            opcodes: Vec::new(),
-        }
-    }
-
-    fn compile(mut self, ir: ir::Ir) -> OpCodes {
-        ir.compile(&mut self);
-        self.opcodes()
-    }
-
-    fn push(&mut self, code: OpCode) {
-        self.opcodes.push(code);
-    }
-
-    fn idx(&self) -> usize {
-        self.opcodes.len()
-    }
-
-    fn modify(&mut self, idx: usize, code: OpCode) {
-        self.opcodes[idx] = code;
-    }
-
-    fn pop(&mut self) -> Option<OpCode> {
-        self.opcodes.pop()
-    }
-
-    fn opcodes(self) -> OpCodes {
-        self.opcodes.into()
-    }
-}
-
-pub trait Compile {
-    fn compile(self, comp: &mut Compiler);
-}
-
-pub trait CompileWithLength {
-    fn compile_with_length(self, comp: &mut Compiler) -> usize;
-}
-
-impl<T: Compile> CompileWithLength for T {
-    fn compile_with_length(self, comp: &mut Compiler) -> usize {
-        let start = comp.idx();
-        self.compile(comp);
-        let end = comp.idx();
-        end - start
-    }
-}
-
-impl Compile for ir::Const {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::Const { idx: self.idx });
-    }
-}
-
-impl Compile for ir::Var {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::LookUp { sym: self.sym });
-    }
-}
-
-impl Compile for ir::Thunk {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::LoadThunk { idx: self.idx });
-    }
-}
-
-impl Compile for ir::Attrs {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::AttrSet {
-            cap: self.stcs.len() + self.dyns.len(),
-        });
-        for stc in self.stcs {
-            stc.1.compile(comp);
-            if !self.rec {
-                comp.push(OpCode::CaptureEnv);
-            }
-            comp.push(OpCode::PushStaticAttr { name: stc.0 });
-        }
-        for dynamic in self.dyns {
-            dynamic.0.compile(comp);
-            dynamic.1.compile(comp);
-            if !self.rec {
-                comp.push(OpCode::CaptureEnv);
-            }
-            comp.push(OpCode::PushDynamicAttr)
-        }
-        if self.rec {
-            comp.push(OpCode::FinalizeRec);
-        }
-    }
-}
-
-impl Compile for ir::List {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::List);
-        for item in self.items {
-            item.compile(comp);
-            comp.push(OpCode::PushElem);
-        }
-    }
-}
-
-impl Compile for ir::UnOp {
-    fn compile(self, comp: &mut Compiler) {
-        use ir::UnOpKind::*;
-        match self.kind {
-            Neg => {
-                self.rhs.compile(comp);
-                comp.push(OpCode::UnOp { op: UnOp::Neg });
-            }
-            Not => {
-                self.rhs.compile(comp);
-                comp.push(OpCode::UnOp { op: UnOp::Not });
-            }
-        }
-    }
-}
-
-impl Compile for ir::BinOp {
-    fn compile(self, comp: &mut Compiler) {
-        use ir::BinOpKind::*;
-        match self.kind {
-            Add => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Add });
-            }
-            Mul => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Mul });
-            }
-            Div => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Div });
-            }
-            And => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::And });
-            }
-            Or => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Or });
-            }
-            Eq => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Eq });
-            }
-            Lt => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Lt });
-            }
-            Con => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Con });
-            }
-            Upd => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Upd });
-            }
-
-            Sub => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Sub });
-            }
-            Impl => {
-                self.lhs.compile(comp);
-                comp.push(OpCode::UnOp { op: UnOp::Not });
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Or });
-            }
-            Neq => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Eq });
-                comp.push(OpCode::UnOp { op: UnOp::Not });
-            }
-            Gt => {
-                self.rhs.compile(comp);
-                self.lhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Lt });
-            }
-            Leq => {
-                self.rhs.compile(comp);
-                self.lhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Lt });
-                comp.push(OpCode::UnOp { op: UnOp::Not });
-            }
-            Geq => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::BinOp { op: BinOp::Lt });
-                comp.push(OpCode::UnOp { op: UnOp::Not });
-            }
-
-            PipeL => {
-                self.lhs.compile(comp);
-                self.rhs.compile(comp);
-                comp.push(OpCode::Call { arity: 1 });
-            }
-            PipeR => {
-                self.rhs.compile(comp);
-                self.lhs.compile(comp);
-                comp.push(OpCode::Call { arity: 1 });
-            }
-        }
-    }
-}
-
-impl Compile for ir::HasAttr {
-    fn compile(self, comp: &mut Compiler) {
-        self.lhs.compile(comp);
-        for attr in self.rhs {
-            match attr {
-                ir::Attr::Str(sym) => {
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectOrDefault { sym })
-                }
-                ir::Attr::Dynamic(dynamic) => {
-                    dynamic.compile(comp);
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectDynamicOrDefault);
-                }
-                ir::Attr::Strs(string) => {
-                    string.compile(comp);
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectDynamicOrDefault);
-                }
-            }
-        }
-        let last = comp.pop().unwrap();
-        let _ = comp.pop();
-        match last {
-            OpCode::SelectOrDefault { sym } => comp.push(OpCode::HasAttr { sym }),
-            OpCode::SelectDynamicOrDefault => comp.push(OpCode::HasDynamicAttr),
-            _ => unreachable!(),
-        }
-    }
-}
-
-impl Compile for ir::Select {
-    fn compile(self, comp: &mut Compiler) {
-        self.expr.compile(comp);
-        for attr in self.attrpath {
-            match attr {
-                ir::Attr::Str(sym) => {
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectOrDefault { sym })
-                }
-                ir::Attr::Dynamic(dynamic) => {
-                    dynamic.compile(comp);
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectDynamicOrDefault);
-                }
-                ir::Attr::Strs(string) => {
-                    string.compile(comp);
-                    comp.push(OpCode::AttrSet { cap: 0 });
-                    comp.push(OpCode::SelectDynamicOrDefault);
-                }
-            }
-        }
-        match self.default {
-            Some(default) => {
-                let last = comp.pop().unwrap();
-                let _ = comp.pop();
-                default.compile(comp);
-                match last {
-                    OpCode::SelectOrDefault { sym } => comp.push(OpCode::SelectOrDefault { sym }),
-                    OpCode::SelectDynamicOrDefault => comp.push(OpCode::SelectDynamicOrDefault),
-                    _ => unreachable!(),
-                }
-            }
-            None => {
-                let last = comp.pop().unwrap();
-                let _ = comp.pop();
-                match last {
-                    OpCode::SelectOrDefault { sym } => comp.push(OpCode::Select { sym }),
-                    OpCode::SelectDynamicOrDefault => comp.push(OpCode::SelectDynamic),
-                    _ => unreachable!(),
-                }
-            }
-        }
-    }
-}
-
-impl Compile for ir::ConcatStrings {
-    fn compile(self, comp: &mut Compiler) {
-        let mut iter = self.parts.into_iter();
-        iter.next().unwrap().compile(comp);
-        for item in iter {
-            item.compile(comp);
-            comp.push(OpCode::ConcatString);
-        }
-    }
-}
-
-impl Compile for ir::If {
-    fn compile(self, comp: &mut Compiler) {
-        self.cond.compile(comp);
-
-        let idx_jmp_if_false = comp.idx();
-        // place holder
-        comp.push(OpCode::Illegal);
-
-        let consq_length = self.consq.compile_with_length(comp);
-
-        let idx_jmp = comp.idx();
-        // place holder
-        comp.push(OpCode::Illegal);
-
-        let alter_length = self.alter.compile_with_length(comp);
-
-        comp.modify(
-            idx_jmp_if_false,
-            OpCode::JmpIfFalse {
-                step: consq_length + 1,
-            },
-        );
-        comp.modify(idx_jmp, OpCode::Jmp { step: alter_length });
-    }
-}
-
-impl Compile for ir::Let {
-    fn compile(self, comp: &mut Compiler) {
-        self.attrs.compile(comp);
-        comp.push(OpCode::EnterEnv);
-        self.expr.compile(comp);
-        comp.push(OpCode::LeaveEnv);
-    }
-}
-
-impl Compile for ir::With {
-    fn compile(self, comp: &mut Compiler) {
-        self.namespace.compile(comp);
-        comp.push(OpCode::EnterEnv);
-        self.expr.compile(comp);
-        comp.push(OpCode::LeaveEnv);
-    }
-}
-
-impl Compile for ir::Assert {
-    fn compile(self, comp: &mut Compiler) {
-        self.assertion.compile(comp);
-        comp.push(OpCode::Assert);
-        self.expr.compile(comp);
-    }
-}
-
-impl Compile for ir::LoadFunc {
-    fn compile(self, comp: &mut Compiler) {
-        comp.push(OpCode::Func { idx: self.idx });
-    }
-}
-
-impl Compile for ir::Call {
-    fn compile(self, comp: &mut Compiler) {
-        let arity = self.args.len();
-        self.func.compile(comp);
-        self.args.into_iter().for_each(|arg| {
-            arg.compile(comp);
-        });
-        comp.push(OpCode::Call { arity });
-    }
-}
-
-impl Compile for ir::Path {
-    fn compile(self, comp: &mut Compiler) {
-        self.expr.compile(comp);
-        comp.push(OpCode::Path);
-    }
-}

src/error.rs

@@ -1,15 +0,0 @@
-use thiserror::Error;
-
-pub type Result<T> = core::result::Result<T, Error>;
-
-#[derive(Error, Debug)]
-pub enum Error {
-    #[error("error occurred during parse stage: {0}")]
-    ParseError(String),
-    #[error("error occurred during downgrade stage: {0}")]
-    DowngradeError(String),
-    #[error("error occurred during evaluation stage: {0}")]
-    EvalError(String),
-    #[error("unknown error")]
-    Unknown,
-}

src/ir.rs

@@ -1,761 +0,0 @@
-use hashbrown::HashMap;
-
-use ecow::EcoString;
-use rnix::ast::{self, Expr};
-
-use crate::compile::*;
-use crate::error::*;
-use crate::ty::internal as i;
-
-pub fn downgrade(expr: Expr) -> Result<Downgraded> {
-    let mut ctx = DowngradeContext::new();
-    let ir = expr.downgrade(&mut ctx)?;
-    Ok(Downgraded {
-        top_level: ir,
-        consts: ctx.consts.into(),
-        symbols: ctx.symbols,
-        symmap: ctx.symmap,
-        thunks: ctx.thunks.into(),
-        funcs: ctx.funcs.into(),
-    })
-}
-
-trait Downcast<T: Sized>
-where
-    Self: Sized,
-{
-    fn downcast_ref(&self) -> Option<&T>;
-    fn downcast_mut(&mut self) -> Option<&mut T>;
-}
-
-macro_rules! ir {
-    (
-        $(
-            $(#[$($x:tt)*])*
-            $ty:ident
-            =>
-            {$($name:ident : $elemtype:ty),*$(,)?}
-        )
-        ,*$(,)?
-    ) => {
-        #[derive(Clone, Debug)]
-        pub enum Ir {
-            $(
-                $ty($ty),
-            )*
-        }
-
-        impl Ir {
-            fn boxed(self) -> Box<Self> {
-                Box::new(self)
-            }
-            fn ok(self) -> Result<Self> {
-                Ok(self)
-            }
-        }
-
-        impl Compile for Ir {
-            fn compile(self, ctx: &mut Compiler) {
-                match self {
-                    $(Ir::$ty(ir) => ir.compile(ctx),)*
-                }
-            }
-        }
-
-        $(
-            $(
-                #[$($x)*]
-            )*
-            #[derive(Clone, Debug)]
-            pub struct $ty {
-                $(
-                    pub $name : $elemtype,
-                )*
-            }
-
-            impl $ty {
-                pub fn ir(self) -> Ir {
-                    Ir::$ty(self)
-                }
-            }
-
-            impl Downcast<$ty> for Ir {
-                fn downcast_ref(&self) -> Option<&$ty> {
-                    match self {
-                        Ir::$ty(value) => Some(value),
-                        _ => None,
-                    }
-                }
-                fn downcast_mut(&mut self) -> Option<&mut $ty> {
-                    match self {
-                        Ir::$ty(value) => Some(value),
-                        _ => None,
-                    }
-                }
-            }
-        )*
-    }
-}
-
-ir! {
-    Attrs => { stcs: HashMap<usize, Ir>, dyns: Vec<DynamicAttrPair>, rec: bool },
-    List  => { items: Vec<Ir> },
-    HasAttr => { lhs: Box<Ir>, rhs: Vec<Attr> },
-    BinOp => { lhs: Box<Ir>, rhs: Box<Ir>, kind: BinOpKind },
-    UnOp  => { rhs: Box<Ir>, kind: UnOpKind },
-    Select => { expr: Box<Ir>, attrpath: Vec<Attr>, default: Option<Box<Ir>> },
-    If => { cond: Box<Ir>, consq: Box<Ir>, alter: Box<Ir> },
-    LoadFunc => { idx: usize },
-    Call => { func: Box<Ir>, args: Vec<Ir> },
-
-    Let => { attrs: Attrs, expr: Box<Ir> },
-    With => { namespace: Box<Ir>, expr: Box<Ir> },
-    Assert => { assertion: Box<Ir>, expr: Box<Ir> },
-    ConcatStrings => { parts: Vec<Ir> },
-    Const => { idx: usize },
-    Var => { sym: usize },
-    #[derive(Copy)]
-    Thunk => { idx: usize },
-    Path => { expr: Box<Ir> },
-}
-
-#[derive(Clone, Debug)]
-pub struct DynamicAttrPair(pub Ir, pub Ir);
-
-#[derive(Default)]
-pub struct DowngradeContext {
-    thunks: Vec<Ir>,
-    funcs: Vec<Func>,
-    consts: Vec<i::Const>,
-    constmap: HashMap<i::Const, usize>,
-    symbols: Vec<EcoString>,
-    symmap: HashMap<EcoString, usize>,
-}
-
-pub struct Downgraded {
-    pub top_level: Ir,
-    pub consts: Box<[i::Const]>,
-    pub symbols: Vec<EcoString>,
-    pub symmap: HashMap<EcoString, usize>,
-    pub thunks: Box<[Ir]>,
-    pub funcs: Box<[Func]>,
-}
-
-impl DowngradeContext {
-    fn new() -> DowngradeContext {
-        DowngradeContext::default()
-    }
-
-    fn new_thunk(&mut self, thunk: Ir) -> Thunk {
-        let idx = self.thunks.len();
-        self.thunks.push(thunk);
-        Thunk { idx }
-    }
-
-    fn new_func(&mut self, func: Func) -> LoadFunc {
-        let idx = self.funcs.len();
-        self.funcs.push(func);
-        LoadFunc { idx }
-    }
-
-    fn new_const(&mut self, cnst: i::Const) -> Const {
-        if let Some(&idx) = self.constmap.get(&cnst) {
-            Const { idx }
-        } else {
-            self.constmap.insert(cnst.clone(), self.consts.len());
-            self.consts.push(cnst);
-            Const {
-                idx: self.consts.len() - 1,
-            }
-        }
-    }
-
-    fn new_sym(&mut self, sym: impl Into<EcoString>) -> usize {
-        let sym = sym.into();
-        if let Some(&idx) = self.symmap.get(&sym) {
-            idx
-        } else {
-            self.symmap.insert(sym.clone(), self.symbols.len());
-            self.symbols.push(sym);
-            self.symbols.len() - 1
-        }
-    }
-}
-
-impl Attrs {
-    fn _insert(&mut self, mut path: std::vec::IntoIter<Attr>, name: Attr, value: Ir) -> Result<()> {
-        if let Some(attr) = path.next() {
-            match attr {
-                Attr::Str(ident) => {
-                    if self.stcs.get(&ident).is_some() {
-                        self.stcs
-                            .get_mut(&ident)
-                            .unwrap()
-                            .downcast_mut()
-                            .ok_or_else(|| {
-                                Error::DowngradeError(format!(
-                                    r#""{ident}" already exsists in this set"#
-                                ))
-                            })
-                            .and_then(|attrs: &mut Attrs| attrs._insert(path, name, value))
-                    } else {
-                        let mut attrs = Attrs {
-                            rec: false,
-                            stcs: HashMap::new(),
-                            dyns: Vec::new(),
-                        };
-                        attrs._insert(path, name, value)?;
-                        assert!(self.stcs.insert(ident, attrs.ir()).is_none());
-                        Ok(())
-                    }
-                }
-                Attr::Strs(string) => {
-                    let mut attrs = Attrs {
-                        rec: false,
-                        stcs: HashMap::new(),
-                        dyns: Vec::new(),
-                    };
-                    attrs._insert(path, name, value)?;
-                    self.dyns.push(DynamicAttrPair(string.ir(), attrs.ir()));
-                    Ok(())
-                }
-                Attr::Dynamic(dynamic) => {
-                    let mut attrs = Attrs {
-                        rec: false,
-                        stcs: HashMap::new(),
-                        dyns: Vec::new(),
-                    };
-                    attrs._insert(path, name, value)?;
-                    self.dyns.push(DynamicAttrPair(dynamic, attrs.ir()));
-                    Ok(())
-                }
-            }
-        } else {
-            match name {
-                Attr::Str(ident) => {
-                    if self.stcs.get(&ident).is_some() {
-                        return Err(Error::DowngradeError(format!(
-                            r#""{ident}" already exsists in this set"#
-                        )));
-                    }
-                    self.stcs.insert(ident, value);
-                }
-                Attr::Strs(string) => {
-                    self.dyns.push(DynamicAttrPair(string.ir(), value));
-                }
-                Attr::Dynamic(dynamic) => {
-                    self.dyns.push(DynamicAttrPair(dynamic, value));
-                }
-            }
-            Ok(())
-        }
-    }
-
-    pub fn insert(&mut self, path: Vec<Attr>, value: Ir) -> Result<()> {
-        let mut path = path.into_iter();
-        let name = path.next_back().unwrap();
-        self._insert(path, name, value)
-    }
-
-    fn _has_attr(&self, mut path: std::slice::Iter<Attr>, name: Attr) -> Option<bool> {
-        match path.next() {
-            Some(Attr::Str(ident)) => self
-                .stcs
-                .get(ident)
-                .and_then(|attrs| attrs.downcast_ref())
-                .map_or(Some(false), |attrs: &Attrs| attrs._has_attr(path, name)),
-            None => match name {
-                Attr::Str(ident) => Some(self.stcs.get(&ident).is_some()),
-                _ => None,
-            },
-            _ => None,
-        }
-    }
-
-    pub fn has_attr(&self, path: &[Attr]) -> Option<bool> {
-        let mut path = path.iter();
-        let name = path.next_back().unwrap().clone();
-        self._has_attr(path, name)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum Attr {
-    Dynamic(Ir),
-    Strs(ConcatStrings),
-    Str(usize),
-}
-
-#[derive(Clone, Debug)]
-pub enum BinOpKind {
-    Add,
-    Sub,
-    Div,
-    Mul,
-    Eq,
-    Neq,
-    Lt,
-    Gt,
-    Leq,
-    Geq,
-    And,
-    Or,
-    Impl,
-
-    Con,
-    Upd,
-
-    PipeL,
-    PipeR,
-}
-
-impl From<ast::BinOpKind> for BinOpKind {
-    fn from(op: ast::BinOpKind) -> Self {
-        use BinOpKind::*;
-        use ast::BinOpKind as astkind;
-        match op {
-            astkind::Concat => Con,
-            astkind::Update => Upd,
-            astkind::Add => Add,
-            astkind::Sub => Sub,
-            astkind::Mul => Mul,
-            astkind::Div => Div,
-            astkind::And => And,
-            astkind::Equal => Eq,
-            astkind::Implication => Impl,
-            astkind::Less => Lt,
-            astkind::LessOrEq => Leq,
-            astkind::More => Gt,
-            astkind::MoreOrEq => Geq,
-            astkind::NotEqual => Neq,
-            astkind::Or => Or,
-            astkind::PipeLeft => PipeL,
-            astkind::PipeRight => PipeR,
-        }
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum UnOpKind {
-    Neg,
-    Not,
-}
-
-impl From<ast::UnaryOpKind> for UnOpKind {
-    fn from(value: ast::UnaryOpKind) -> Self {
-        match value {
-            ast::UnaryOpKind::Invert => UnOpKind::Not,
-            ast::UnaryOpKind::Negate => UnOpKind::Neg,
-        }
-    }
-}
-
-pub struct Func {
-    pub param: Param,
-    pub body: Box<Ir>,
-}
-
-#[derive(Clone, Debug)]
-pub enum Param {
-    Ident(usize),
-    Formals {
-        formals: Vec<(usize, Option<Thunk>)>,
-        ellipsis: bool,
-        alias: Option<usize>,
-    },
-}
-
-trait Downgrade
-where
-    Self: Sized,
-{
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir>;
-}
-
-impl Downgrade for Expr {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        match self {
-            Expr::Apply(apply) => apply.downgrade(ctx),
-            Expr::Assert(assert) => assert.downgrade(ctx),
-            Expr::Error(error) => Err(Error::DowngradeError(error.to_string())),
-            Expr::IfElse(ifelse) => ifelse.downgrade(ctx),
-            Expr::Select(select) => select.downgrade(ctx),
-            Expr::Str(str) => str.downgrade(ctx),
-            Expr::Path(path) => path.downgrade(ctx),
-            Expr::Literal(lit) => lit.downgrade(ctx),
-            Expr::Lambda(lambda) => lambda.downgrade(ctx),
-            Expr::LegacyLet(let_) => let_.downgrade(ctx),
-            Expr::LetIn(letin) => letin.downgrade(ctx),
-            Expr::List(list) => list.downgrade(ctx),
-            Expr::BinOp(op) => op.downgrade(ctx),
-            Expr::Paren(paren) => paren.expr().unwrap().downgrade(ctx),
-            Expr::Root(root) => root.expr().unwrap().downgrade(ctx),
-            Expr::AttrSet(attrs) => attrs.downgrade(ctx),
-            Expr::UnaryOp(op) => op.downgrade(ctx),
-            Expr::Ident(ident) => ident.downgrade(ctx),
-            Expr::With(with) => with.downgrade(ctx),
-            Expr::HasAttr(has) => has.downgrade(ctx),
-        }
-    }
-}
-
-impl Downgrade for ast::Assert {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        Assert {
-            assertion: self.condition().unwrap().downgrade(ctx)?.boxed(),
-            expr: self.body().unwrap().downgrade(ctx)?.boxed(),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::IfElse {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        If {
-            cond: self.condition().unwrap().downgrade(ctx)?.boxed(),
-            consq: self.body().unwrap().downgrade(ctx)?.boxed(),
-            alter: self.else_body().unwrap().downgrade(ctx)?.boxed(),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::Path {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let parts = self
-            .parts()
-            .map(|part| match part {
-                ast::InterpolPart::Literal(lit) => ctx.new_const(lit.to_string().into()).ir().ok(),
-                ast::InterpolPart::Interpolation(interpol) => {
-                    interpol.expr().unwrap().downgrade(ctx)
-                }
-            })
-            .collect::<Result<Vec<_>>>()?;
-        if parts.len() == 1 {
-            Path {
-                expr: parts.into_iter().next().unwrap().boxed(),
-            }
-        } else {
-            Path {
-                expr: ConcatStrings { parts }.ir().boxed(),
-            }
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::Str {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let parts = self
-            .normalized_parts()
-            .into_iter()
-            .map(|part| match part {
-                ast::InterpolPart::Literal(lit) => ctx.new_const(lit.into()).ir().ok(),
-                ast::InterpolPart::Interpolation(interpol) => {
-                    interpol.expr().unwrap().downgrade(ctx)
-                }
-            })
-            .collect::<Result<Vec<_>>>()?;
-        if parts.len() == 1 {
-            Ok(parts.into_iter().next().unwrap())
-        } else {
-            ConcatStrings { parts }.ir().ok()
-        }
-    }
-}
-
-impl Downgrade for ast::Literal {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        match self.kind() {
-            ast::LiteralKind::Integer(int) => ctx.new_const(int.value().unwrap().into()),
-            ast::LiteralKind::Float(float) => ctx.new_const(float.value().unwrap().into()),
-            ast::LiteralKind::Uri(uri) => ctx.new_const(uri.to_string().into()),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::Ident {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        Var {
-            sym: ctx.new_sym(self.to_string()),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::AttrSet {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let rec = self.rec_token().is_some();
-        downgrade_has_entry(self, rec, ctx).map(|attrs| attrs.ir())
-    }
-}
-
-impl Downgrade for ast::List {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let mut items = Vec::with_capacity(self.items().size_hint().0);
-        for item in self.items() {
-            items.push(item.downgrade(ctx)?)
-        }
-        List { items }.ir().ok()
-    }
-}
-
-impl Downgrade for ast::BinOp {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        BinOp {
-            lhs: self.lhs().unwrap().downgrade(ctx)?.boxed(),
-            rhs: self.rhs().unwrap().downgrade(ctx)?.boxed(),
-            kind: self.operator().unwrap().into(),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::HasAttr {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let attrs = self.expr().unwrap().downgrade(ctx)?;
-        let path = downgrade_attrpath(self.attrpath().unwrap(), ctx)?;
-        HasAttr {
-            lhs: attrs.boxed(),
-            rhs: path,
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::UnaryOp {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        UnOp {
-            rhs: self.expr().unwrap().downgrade(ctx)?.boxed(),
-            kind: self.operator().unwrap().into(),
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::Select {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        Select {
-            expr: self.expr().unwrap().downgrade(ctx)?.boxed(),
-            attrpath: downgrade_attrpath(self.attrpath().unwrap(), ctx)?,
-            default: match self.default_expr() {
-                Some(default) => Some(default.downgrade(ctx)?.boxed()),
-                None => None,
-            },
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::LegacyLet {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let attrs = downgrade_has_entry(self, true, ctx)?;
-        Select {
-            expr: attrs.ir().boxed(),
-            attrpath: vec![Attr::Str(ctx.new_sym("body".to_string()))],
-            default: None,
-        }
-        .ir()
-        .ok()
-    }
-}
-
-impl Downgrade for ast::LetIn {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let body = self.body().unwrap();
-        let attrs = downgrade_has_entry(self, true, ctx)?;
-        let expr = body.downgrade(ctx)?.boxed();
-        Let { attrs, expr }.ir().ok()
-    }
-}
-
-impl Downgrade for ast::With {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let namespace = self.namespace().unwrap().downgrade(ctx)?;
-        if let Ir::Attrs(attrs) = namespace {
-            let expr = self.body().unwrap().downgrade(ctx)?.boxed();
-            Let { attrs, expr }.ir().ok()
-        } else {
-            let namespace = namespace.boxed();
-            let expr = self.body().unwrap().downgrade(ctx)?.boxed();
-            With { namespace, expr }.ir().ok()
-        }
-    }
-}
-
-impl Downgrade for ast::Lambda {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let body = self.body().unwrap();
-        let param = downgrade_param(self.param().unwrap(), ctx)?;
-        let body = body.downgrade(ctx)?.boxed();
-        ctx.new_func(Func { param, body }).ir().ok()
-    }
-}
-
-impl Downgrade for ast::Apply {
-    fn downgrade(self, ctx: &mut DowngradeContext) -> Result<Ir> {
-        let mut args = vec![self.argument().unwrap().downgrade(ctx)?];
-        let mut func = self.lambda().unwrap();
-        while let ast::Expr::Apply(call) = func {
-            func = call.lambda().unwrap();
-            args.push(call.argument().unwrap().downgrade(ctx)?);
-        }
-        let func = func.downgrade(ctx)?.boxed();
-        args.reverse();
-        Call { func, args }.ir().ok()
-    }
-}
-
-fn downgrade_param(param: ast::Param, ctx: &mut DowngradeContext) -> Result<Param> {
-    match param {
-        ast::Param::IdentParam(ident) => Ok(Param::Ident(ctx.new_sym(ident.to_string()))),
-        ast::Param::Pattern(pattern) => downgrade_pattern(pattern, ctx),
-    }
-}
-
-fn downgrade_pattern(pattern: ast::Pattern, ctx: &mut DowngradeContext) -> Result<Param> {
-    let formals = pattern
-        .pat_entries()
-        .map(|entry| {
-            let ident = ctx.new_sym(entry.ident().unwrap().to_string());
-            if entry.default().is_none() {
-                Ok((ident, None))
-            } else {
-                entry
-                    .default()
-                    .unwrap()
-                    .downgrade(ctx)
-                    .map(|ok| (ident, Some(ctx.new_thunk(ok))))
-            }
-        })
-        .collect::<Result<Vec<_>>>()?;
-    let ellipsis = pattern.ellipsis_token().is_some();
-    let alias = pattern
-        .pat_bind()
-        .map(|alias| ctx.new_sym(alias.ident().unwrap().to_string()));
-    Ok(Param::Formals {
-        formals,
-        ellipsis,
-        alias,
-    })
-}
-
-fn downgrade_has_entry(
-    has_entry: impl ast::HasEntry,
-    rec: bool,
-    ctx: &mut DowngradeContext,
-) -> Result<Attrs> {
-    let entires = has_entry.entries();
-    let mut attrs = Attrs {
-        rec,
-        stcs: HashMap::new(),
-        dyns: Vec::new(),
-    };
-
-    for entry in entires {
-        match entry {
-            ast::Entry::Inherit(inherit) => downgrade_inherit(inherit, &mut attrs.stcs, ctx)?,
-            ast::Entry::AttrpathValue(value) => downgrade_attrpathvalue(value, &mut attrs, ctx)?,
-        }
-    }
-
-    Ok(attrs)
-}
-
-fn downgrade_inherit(
-    inherit: ast::Inherit,
-    stcs: &mut HashMap<usize, Ir>,
-    ctx: &mut DowngradeContext,
-) -> Result<()> {
-    let from = if let Some(from) = inherit.from() {
-        let from = from.expr().unwrap().downgrade(ctx)?;
-        Some(ctx.new_thunk(from))
-    } else {
-        None
-    };
-    for attr in inherit.attrs() {
-        let ident = match downgrade_attr(attr, ctx)? {
-            Attr::Str(ident) => ident,
-            _ => {
-                return Err(Error::DowngradeError(
-                    "dynamic attributes not allowed in inherit".to_string(),
-                ));
-            }
-        };
-        let expr = from.map_or_else(
-            || Var { sym: ident }.ir().ok(),
-            |from| {
-                Ok(Select {
-                    expr: from.ir().boxed(),
-                    attrpath: vec![Attr::Str(ident)],
-                    default: None,
-                }
-                .ir())
-            },
-        )?;
-        assert!(stcs.insert(ident, expr).is_none());
-    }
-    Ok(())
-}
-
-fn downgrade_attr(attr: ast::Attr, ctx: &mut DowngradeContext) -> Result<Attr> {
-    use ast::Attr::*;
-    use ast::InterpolPart::*;
-    match attr {
-        Ident(ident) => Ok(Attr::Str(ctx.new_sym(ident.to_string()))),
-        Str(string) => {
-            let parts = string.normalized_parts();
-            if parts.len() == 0 {
-                Ok(Attr::Str(ctx.new_sym("")))
-            } else if parts.len() == 1 {
-                match parts.into_iter().next().unwrap() {
-                    Literal(ident) => Ok(Attr::Str(ctx.new_sym(ident))),
-                    Interpolation(interpol) => {
-                        Ok(Attr::Dynamic(interpol.expr().unwrap().downgrade(ctx)?))
-                    }
-                }
-            } else {
-                let parts = parts
-                    .into_iter()
-                    .map(|part| match part {
-                        Literal(lit) => ctx.new_const(lit.into()).ir().ok(),
-                        Interpolation(interpol) => interpol.expr().unwrap().downgrade(ctx),
-                    })
-                    .collect::<Result<Vec<_>>>()?;
-                Ok(Attr::Strs(ConcatStrings { parts }))
-            }
-        }
-        Dynamic(dynamic) => Ok(Attr::Dynamic(dynamic.expr().unwrap().downgrade(ctx)?)),
-    }
-}
-
-fn downgrade_attrpath(attrpath: ast::Attrpath, ctx: &mut DowngradeContext) -> Result<Vec<Attr>> {
-    attrpath
-        .attrs()
-        .map(|attr| downgrade_attr(attr, ctx))
-        .collect::<Result<Vec<_>>>()
-}
-
-fn downgrade_attrpathvalue(
-    value: ast::AttrpathValue,
-    attrs: &mut Attrs,
-    ctx: &mut DowngradeContext,
-) -> Result<()> {
-    let path = downgrade_attrpath(value.attrpath().unwrap(), ctx)?;
-    let value = value.value().unwrap().downgrade(ctx)?;
-    let value = match value {
-        x @ Ir::Const(_) => x,
-        x => ctx.new_thunk(x).ir(),
-    };
-    attrs.insert(path, value)
-}

src/lib.rs

@@ -1,14 +0,0 @@
-#![cfg_attr(test, feature(test))]
-#![allow(dead_code)]
-
-mod builtins;
-mod bytecode;
-mod stack;
-mod ty;
-
-pub mod compile;
-pub mod error;
-pub mod ir;
-pub mod vm;
-
-pub use ty::public::Value;

src/stack.rs

@@ -1,84 +0,0 @@
-use std::mem::{MaybeUninit, replace, transmute};
-use std::ops::Deref;
-
-use crate::error::*;
-
-pub struct Stack<T, const CAP: usize> {
-    items: [MaybeUninit<T>; CAP],
-    top: usize,
-}
-
-macro_rules! into {
-    ($e:expr) => {
-        // SAFETY: This macro is used to transmute `MaybeUninit<Value<'vm>>` to `Value<'vm>`
-        // or `&MaybeUninit<Value<'vm>>` to `&Value<'vm>`.
-        // This is safe because the `Stack` ensures that only initialized values are accessed
-        // within the `0..top` range.
-        unsafe { transmute($e) }
-    };
-}
-
-impl<T, const CAP: usize> Stack<T, CAP> {
-    pub fn new() -> Self {
-        Stack {
-            items: [const { MaybeUninit::uninit() }; CAP],
-            top: 0,
-        }
-    }
-
-    pub fn push(&mut self, item: T) -> Result<()> {
-        self.items
-            .get_mut(self.top)
-            .map_or_else(
-                || Err(Error::EvalError("stack overflow".to_string())),
-                |ok| Ok(ok),
-            )?
-            .write(item);
-        self.top += 1;
-        Ok(())
-    }
-
-    pub fn pop(&mut self) -> T {
-        self.top -= 1;
-        let item = self.items.get_mut(self.top).unwrap();
-
-        // SAFETY: `item` at `self.top` was previously written and is initialized.
-        // We replace it with `MaybeUninit::uninit()` and then `assume_init`
-        // on the original value, which is safe as it was initialized.
-        unsafe { replace(item, MaybeUninit::uninit()).assume_init() }
-    }
-
-    pub fn tos(&self) -> Result<&T> {
-        if self.top == 0 {
-            panic!("stack empty")
-        } else {
-            Ok(into!(&self.items[self.top - 1]))
-        }
-    }
-
-    pub fn tos_mut(&mut self) -> Result<&mut T> {
-        if self.top == 0 {
-            panic!("stack empty")
-        } else {
-            Ok(into!(&mut self.items[self.top - 1]))
-        }
-    }
-}
-
-impl<T, const CAP: usize> Deref for Stack<T, CAP> {
-    type Target = [T];
-    fn deref(&self) -> &Self::Target {
-        into!(&self.items[0..self.top])
-    }
-}
-
-impl<T, const CAP: usize> Drop for Stack<T, CAP> {
-    fn drop(&mut self) {
-        self.items.as_mut_slice()[0..self.top]
-            .iter_mut()
-            // SAFETY: Items in the range `0..self.top` are guaranteed to be initialized.
-            // `assume_init_drop` is called to correctly drop these initialized `Value`s.
-            .map(|item| unsafe { item.assume_init_drop() })
-            .for_each(drop)
-    }
-}

src/ty/common.rs

@@ -1,14 +0,0 @@
-use std::fmt::{Display, Formatter, Result as FmtResult};
-
-use derive_more::Constructor;
-
-#[derive(Clone, Debug, PartialEq, Constructor, Hash)]
-pub struct Catchable {
-    msg: String,
-}
-
-impl Display for Catchable {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        write!(f, "<error: {}>", self.msg)
-    }
-}

src/ty/internal/attrset.rs

@@ -1,103 +0,0 @@
-use hashbrown::{HashMap, HashSet};
-
-use derive_more::Constructor;
-use itertools::Itertools;
-
-use crate::error::Result;
-use crate::vm::{Env, VM};
-
-use super::super::public as p;
-use super::Value;
-
-#[repr(C)]
-#[derive(Debug, Constructor, Clone, PartialEq)]
-pub struct AttrSet<'vm> {
-    data: HashMap<usize, Value<'vm>>,
-}
-
-impl<'vm> AttrSet<'vm> {
-    pub fn empty() -> Self {
-        AttrSet {
-            data: HashMap::new(),
-        }
-    }
-
-    pub fn with_capacity(cap: usize) -> Self {
-        AttrSet {
-            data: HashMap::with_capacity(cap),
-        }
-    }
-
-    pub fn push_attr_force(&mut self, sym: usize, val: Value<'vm>) {
-        self.data.insert(sym, val);
-    }
-
-    pub fn push_attr(&mut self, sym: usize, val: Value<'vm>) {
-        if self.data.get(&sym).is_some() {
-            todo!()
-        }
-        self.data.insert(sym, val);
-    }
-
-    pub fn select(&self, sym: usize) -> Option<Value<'vm>> {
-        self.data.get(&sym).cloned()
-    }
-
-    pub fn has_attr(&self, sym: usize) -> bool {
-        self.data.get(&sym).is_some()
-    }
-
-    pub fn capture(&mut self, env: &Env<'vm>) {
-        self.data.iter().for_each(|(_, v)| match v.clone() {
-            Value::Thunk(ref thunk) => {
-                thunk.capture(env.clone());
-            }
-            _ => (),
-        })
-    }
-
-    pub fn update(&mut self, other: &AttrSet<'vm>) {
-        for (k, v) in other.data.iter() {
-            self.push_attr_force(k.clone(), v.clone())
-        }
-    }
-
-    pub fn as_inner(&self) -> &HashMap<usize, Value<'vm>> {
-        &self.data
-    }
-
-    pub fn from_inner(data: HashMap<usize, Value<'vm>>) -> Self {
-        Self { data }
-    }
-
-    pub fn force_deep(&mut self, vm: &'vm VM<'_>) -> Result<()> {
-        let mut map: Vec<_> = self
-            .data
-            .iter()
-            .map(|(k, v)| (k.clone(), v.clone()))
-            .collect();
-        for (_, v) in map.iter_mut() {
-            v.force_deep(vm)?;
-        }
-        self.data = map.into_iter().collect();
-        Ok(())
-    }
-
-    pub fn eq_impl(&self, other: &AttrSet<'vm>, vm: &'vm VM<'_>) -> bool {
-        self.data.iter().len() == other.data.iter().len()
-            && std::iter::zip(
-                self.data.iter().sorted_by_key(|(k, _)| **k),
-                self.data.iter().sorted_by_key(|(k, _)| **k),
-            )
-            .all(|((_, v1), (_, v2))| v1.eq_impl(v2, vm))
-    }
-
-    pub fn to_public(&self, vm: &'vm VM, seen: &mut HashSet<Value<'vm>>) -> p::Value {
-        p::Value::AttrSet(p::AttrSet::new(
-            self.data
-                .iter()
-                .map(|(&sym, value)| (vm.get_sym(sym), value.to_public(vm, seen)))
-                .collect(),
-        ))
-    }
-}

src/ty/internal/cnst.rs

@@ -1,79 +0,0 @@
-use std::hash::Hash;
-
-use derive_more::{IsVariant, Unwrap};
-use ecow::EcoString;
-
-#[derive(Debug, Clone, IsVariant, Unwrap)]
-pub enum Const {
-    Bool(bool),
-    Int(i64),
-    Float(f64),
-    String(EcoString),
-    Null,
-}
-
-impl Hash for Const {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        use Const::*;
-        match self {
-            Int(x) => x.hash(state),
-            Float(x) => x.to_bits().hash(state),
-            Bool(x) => x.hash(state),
-            String(x) => x.hash(state),
-            x @ Null => x.hash(state),
-        }
-    }
-}
-
-impl From<bool> for Const {
-    fn from(value: bool) -> Self {
-        Const::Bool(value)
-    }
-}
-
-impl From<i64> for Const {
-    fn from(value: i64) -> Self {
-        Const::Int(value)
-    }
-}
-
-impl From<f64> for Const {
-    fn from(value: f64) -> Self {
-        Const::Float(value)
-    }
-}
-
-impl From<EcoString> for Const {
-    fn from(value: EcoString) -> Self {
-        Const::String(value)
-    }
-}
-
-impl From<String> for Const {
-    fn from(value: String) -> Self {
-        Const::String(value.into())
-    }
-}
-
-impl From<&str> for Const {
-    fn from(value: &str) -> Self {
-        Const::String(value.into())
-    }
-}
-
-impl PartialEq for Const {
-    fn eq(&self, other: &Self) -> bool {
-        use Const::*;
-        match (self, other) {
-            (Bool(a), Bool(b)) => a == b,
-            (Int(a), Int(b)) => a == b,
-            (Float(a), Float(b)) => a == b,
-            (Int(a), Float(b)) => *a as f64 == *b,
-            (Float(a), Int(b)) => *b as f64 == *a,
-            (String(a), String(b)) => a == b,
-            _ => false,
-        }
-    }
-}
-
-impl Eq for Const {}

src/ty/internal/func.rs

@@ -1,100 +0,0 @@
-use derive_more::Constructor;
-use itertools::Itertools;
-
-use crate::bytecode::Func as BFunc;
-use crate::error::Result;
-use crate::ir;
-use crate::ty::internal::{Thunk, Value};
-use crate::vm::{Env, VM};
-
-#[derive(Debug, Clone)]
-pub enum Param {
-    Ident(usize),
-    Formals {
-        formals: Vec<(usize, Option<usize>)>,
-        ellipsis: bool,
-        alias: Option<usize>,
-    },
-}
-
-impl From<ir::Param> for Param {
-    fn from(value: ir::Param) -> Self {
-        match value {
-            ir::Param::Ident(ident) => Param::Ident(ident),
-            ir::Param::Formals {
-                formals,
-                ellipsis,
-                alias,
-            } => Param::Formals {
-                formals: formals
-                    .into_iter()
-                    .map(|(sym, default)| (sym, default.map(|default| default.idx)))
-                    .collect(),
-                ellipsis,
-                alias,
-            },
-        }
-    }
-}
-
-pub type JITFunc<'vm> =
-    unsafe extern "C" fn(vm: *mut VM<'_>, *mut Env<'vm>, *mut Value<'vm>) -> Value<'vm>;
-
-#[derive(Debug, Clone, Constructor)]
-pub struct Func<'vm> {
-    pub func: &'vm BFunc,
-    pub env: Env<'vm>,
-    pub compiled: Option<JITFunc<'vm>>,
-}
-
-impl<'vm> Func<'vm> {
-    pub fn call(&self, vm: &'vm VM<'_>, arg: Value<'vm>) -> Result<Value<'vm>> {
-        use Param::*;
-
-        let mut env = self.env.clone();
-
-        match self.func.param.clone() {
-            Ident(ident) => env = env.enter([(ident.into(), arg)].into_iter()),
-            Formals {
-                formals,
-                ellipsis,
-                alias,
-            } => {
-                let arg = arg.unwrap_attr_set();
-                let mut new = Vec::with_capacity(formals.len() + alias.iter().len());
-                if !ellipsis
-                    && arg
-                        .as_inner()
-                        .iter()
-                        .map(|(k, _)| k)
-                        .sorted()
-                        .ne(formals.iter().map(|(k, _)| k).sorted())
-                {
-                    todo!()
-                }
-                for (formal, default) in formals {
-                    let formal = formal.clone().into();
-                    let arg = arg
-                        .select(formal)
-                        .or_else(|| {
-                            default.map(|idx| Value::Thunk(Thunk::new(vm.get_thunk(idx)).into()))
-                        })
-                        .unwrap();
-                    new.push((formal, arg));
-                }
-                if let Some(alias) = alias {
-                    new.push((alias.clone().into(), Value::AttrSet(arg)));
-                }
-                env = env.enter(new.into_iter());
-            }
-        }
-
-        vm.eval(self.func.opcodes.iter().copied(), env)
-    }
-}
-
-impl PartialEq for Func<'_> {
-    fn eq(&self, _: &Self) -> bool {
-        false
-    }
-}

src/ty/internal/list.rs

@@ -1,51 +0,0 @@
-use hashbrown::HashSet;
-
-use derive_more::Constructor;
-use rpds::Vector;
-
-use crate::error::Result;
-use crate::ty::public as p;
-use crate::vm::VM;
-
-use super::Value;
-
-#[derive(Debug, Constructor, Clone, PartialEq)]
-pub struct List<'vm> {
-    data: Vector<Value<'vm>>,
-}
-
-impl<'vm> List<'vm> {
-    pub fn empty() -> Self {
-        List {
-            data: Vector::new(),
-        }
-    }
-
-    pub fn push(&mut self, elem: Value<'vm>) {
-        self.data.push_back_mut(elem);
-    }
-
-    pub fn concat(&mut self, other: &List<'vm>) {
-        for elem in other.data.iter() {
-            self.data.push_back_mut(elem.clone());
-        }
-    }
-
-    pub fn force_deep(&mut self, vm: &'vm VM<'_>) -> Result<()> {
-        let mut vec: Vec<_> = self.data.iter().cloned().collect();
-        for v in vec.iter_mut() {
-            v.force_deep(vm)?;
-        }
-        self.data = vec.into_iter().collect();
-        Ok(())
-    }
-
-    pub fn to_public(&self, vm: &'vm VM, seen: &mut HashSet<Value<'vm>>) -> p::Value {
-        p::Value::List(p::List::new(
-            self.data
-                .iter()
-                .map(|value| value.clone().to_public(vm, seen))
-                .collect(),
-        ))
-    }
-}

src/ty/internal/mod.rs

@@ -1,523 +0,0 @@
-use hashbrown::HashSet;
-use std::cell::OnceCell;
-use std::cell::RefCell;
-use std::hash::Hash;
-use std::rc::Rc;
-
-use derive_more::{IsVariant, Unwrap};
-
-use super::common as c;
-use super::public as p;
-
-use crate::bytecode::OpCodes;
-use crate::error::*;
-use crate::vm::{Env, VM};
-
-mod attrset;
-mod cnst;
-mod func;
-mod list;
-mod primop;
-mod string;
-
-pub use attrset::*;
-pub use cnst::Const;
-pub use func::*;
-pub use list::List;
-pub use primop::*;
-
-#[derive(Debug, IsVariant, Unwrap, Clone, PartialEq)]
-pub enum Value<'vm> {
-    Const(Const),
-    Thunk(Rc<Thunk<'vm>>),
-    ThunkRef(&'vm Thunk<'vm>),
-    AttrSet(Rc<AttrSet<'vm>>),
-    List(Rc<List<'vm>>),
-    Catchable(c::Catchable),
-    PrimOp(Rc<PrimOp<'vm>>),
-    PartialPrimOp(Rc<PartialPrimOp<'vm>>),
-    Func(Rc<Func<'vm>>),
-    Builtins,
-}
-
-impl Hash for Value<'_> {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        use Value::*;
-        std::mem::discriminant(self).hash(state);
-        match self {
-            Const(x) => x.hash(state),
-            Thunk(x) => (x.as_ref() as *const self::Thunk).hash(state),
-            ThunkRef(x) => (*x as *const self::Thunk).hash(state),
-            AttrSet(x) => (x.as_ref() as *const self::AttrSet).hash(state),
-            List(x) => (x.as_ref() as *const self::List).hash(state),
-            Catchable(x) => x.hash(state),
-            PrimOp(x) => (x.as_ref() as *const self::PrimOp).hash(state),
-            PartialPrimOp(x) => (x.as_ref() as *const self::PartialPrimOp).hash(state),
-            Func(x) => (x.as_ref() as *const self::Func).hash(state),
-            Builtins => (),
-        }
-    }
-}
-
-impl<'vm> Value<'vm> {
-    fn eq_impl(&self, other: &Self, vm: &'vm VM<'_>) -> bool {
-        use Value::*;
-        match (self, other) {
-            (Const(a), Const(b)) => a.eq(b),
-            (AttrSet(a), AttrSet(b)) => a.eq_impl(b, vm),
-            (List(a), List(b)) => a.eq(b),
-            (Builtins, AttrSet(attrs)) => attrs.has_attr(vm.new_sym("builtins")),
-            (AttrSet(attrs), Builtins) => attrs.has_attr(vm.new_sym("builtins")),
-            _ => false,
-        }
-    }
-}
-
-impl Eq for Value<'_> {}
-
-#[derive(Debug, IsVariant, Unwrap, Clone, PartialEq)]
-pub enum ValueAsRef<'v, 'vm: 'v> {
-    Const(&'v Const),
-    Thunk(&'v Thunk<'vm>),
-    AttrSet(&'v AttrSet<'vm>),
-    List(&'v List<'vm>),
-    Catchable(&'v c::Catchable),
-    PrimOp(&'v PrimOp<'vm>),
-    PartialPrimOp(&'v PartialPrimOp<'vm>),
-    Func(&'v Func<'vm>),
-}
-
-#[derive(Debug, IsVariant, Unwrap, PartialEq)]
-pub enum ValueAsMut<'v, 'vm: 'v> {
-    Const(&'v mut Const),
-    Thunk(&'v Thunk<'vm>),
-    AttrSet(&'v mut AttrSet<'vm>),
-    List(&'v mut List<'vm>),
-    Catchable(&'v mut c::Catchable),
-    PrimOp(&'v mut PrimOp<'vm>),
-    PartialPrimOp(&'v mut PartialPrimOp<'vm>),
-    Func(&'v Func<'vm>),
-}
-
-impl<'v, 'vm: 'v> Value<'vm> {
-    pub fn as_ref(&'v self) -> ValueAsRef<'v, 'vm> {
-        use Value::*;
-        use ValueAsRef as R;
-        match self {
-            Const(x) => R::Const(x),
-            Thunk(x) => R::Thunk(x),
-            ThunkRef(x) => R::Thunk(x),
-            AttrSet(x) => R::AttrSet(x),
-            List(x) => R::List(x),
-            Catchable(x) => R::Catchable(x),
-            PrimOp(x) => R::PrimOp(x),
-            PartialPrimOp(x) => R::PartialPrimOp(x),
-            Func(x) => R::Func(x),
-            Builtins => unreachable!(),
-        }
-    }
-
-    pub fn as_mut(&'v mut self) -> ValueAsMut<'v, 'vm> {
-        use Value::*;
-        use ValueAsMut as M;
-        match self {
-            Const(x) => M::Const(x),
-            Thunk(x) => M::Thunk(x),
-            ThunkRef(x) => M::Thunk(x),
-            AttrSet(x) => M::AttrSet(Rc::make_mut(x)),
-            List(x) => M::List(Rc::make_mut(x)),
-            Catchable(x) => M::Catchable(x),
-            PrimOp(x) => M::PrimOp(Rc::make_mut(x)),
-            PartialPrimOp(x) => M::PartialPrimOp(Rc::make_mut(x)),
-            Func(x) => M::Func(x),
-            Builtins => unreachable!(),
-        }
-    }
-}
-
-use Value::Const as VmConst;
-impl<'vm> Value<'vm> {
-    pub fn ok(self) -> Result<Self> {
-        Ok(self)
-    }
-
-    pub fn typename(&self) -> &'static str {
-        use Value::*;
-        match self {
-            Const(_) => unreachable!(),
-            Thunk(_) => "thunk",
-            ThunkRef(_) => "thunk",
-            AttrSet(_) => "set",
-            List(_) => "list",
-            Catchable(_) => unreachable!(),
-            PrimOp(_) => "lambda",
-            PartialPrimOp(_) => "lambda",
-            Func(_) => "lambda",
-            Builtins => "set",
-        }
-    }
-
-    pub fn callable(&self) -> bool {
-        match self {
-            Value::PrimOp(_) | Value::PartialPrimOp(_) | Value::Func(_) => true,
-            Value::AttrSet(_) => todo!(),
-            _ => false,
-        }
-    }
-
-    pub fn call(&self, vm: &'vm VM<'_>, args: Vec<Self>) -> Result<Self> {
-        use Value::*;
-        match self {
-            PrimOp(func) => func.call(vm, args),
-            PartialPrimOp(func) => func.call(vm, args),
-            func @ Value::Func(_) => {
-                let mut iter = args.into_iter();
-                let mut func = func.clone();
-                while let Some(arg) = iter.next() {
-                    func = match func {
-                        PrimOp(func) => {
-                            return func.call(vm, [arg].into_iter().chain(iter).collect());
-                        }
-                        PartialPrimOp(func) => {
-                            return func.call(vm, [arg].into_iter().chain(iter).collect());
-                        }
-                        Func(func) => func.call(vm, arg)?,
-                        _ => todo!(),
-                    }
-                }
-                func.ok()
-            }
-            x @ Catchable(_) => x.clone().ok(),
-            _ => todo!(),
-        }
-    }
-
-    pub fn not(self) -> Self {
-        use Const::*;
-        match self {
-            VmConst(Bool(bool)) => VmConst(Bool(!bool)),
-            x @ Value::Catchable(_) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn and(self, other: Self) -> Self {
-        use Const::*;
-        match (self, other) {
-            (VmConst(Bool(a)), VmConst(Bool(b))) => VmConst(Bool(a && b)),
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn or(self, other: Self) -> Self {
-        use Const::*;
-        match (self, other) {
-            (VmConst(Bool(a)), VmConst(Bool(b))) => VmConst(Bool(a || b)),
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn eq(self, other: Self, vm: &'vm VM<'_>) -> Self {
-        use Const::Bool;
-        match (self, other) {
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            (s, other) => VmConst(Bool(s.eq_impl(&other, vm))),
-        }
-    }
-
-    pub fn lt(self, other: Self) -> Self {
-        use Const::*;
-        VmConst(Bool(match (self, other) {
-            (VmConst(Int(a)), VmConst(Int(b))) => a < b,
-            (VmConst(Int(a)), VmConst(Float(b))) => (a as f64) < b,
-            (VmConst(Float(a)), VmConst(Int(b))) => a < b as f64,
-            (VmConst(Float(a)), VmConst(Float(b))) => a < b,
-            (VmConst(String(a)), VmConst(String(b))) => a < b,
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => return x,
-            _ => todo!(),
-        }))
-    }
-
-    pub fn neg(self) -> Self {
-        use Const::*;
-        match self {
-            VmConst(Int(int)) => VmConst(Int(-int)),
-            VmConst(Float(float)) => VmConst(Float(-float)),
-            x @ Value::Catchable(_) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn add(self, other: Self) -> Self {
-        use Const::*;
-        match (self, other) {
-            (VmConst(Int(a)), VmConst(Int(b))) => VmConst(Int(a + b)),
-            (VmConst(Int(a)), VmConst(Float(b))) => VmConst(Float(a as f64 + b)),
-            (VmConst(Float(a)), VmConst(Int(b))) => VmConst(Float(a + b as f64)),
-            (VmConst(Float(a)), VmConst(Float(b))) => VmConst(Float(a + b)),
-            (VmConst(String(a)), VmConst(String(b))) => {
-                let mut string = a.clone();
-                string.push_str(b.as_str());
-                VmConst(String(string))
-            }
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn mul(self, other: Self) -> Self {
-        use Const::*;
-        match (self, other) {
-            (VmConst(Int(a)), VmConst(Int(b))) => VmConst(Int(a * b)),
-            (VmConst(Int(a)), VmConst(Float(b))) => VmConst(Float(a as f64 * b)),
-            (VmConst(Float(a)), VmConst(Int(b))) => VmConst(Float(a * b as f64)),
-            (VmConst(Float(a)), VmConst(Float(b))) => VmConst(Float(a * b)),
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn div(self, other: Self) -> Result<Self> {
-        use Const::*;
-        Ok(match (self, other) {
-            (_, VmConst(Int(0))) => return Err(Error::EvalError("division by zero".to_string())),
-            (_, VmConst(Float(0.))) => {
-                return Err(Error::EvalError("division by zero".to_string()));
-            }
-            (VmConst(Int(a)), VmConst(Int(b))) => VmConst(Int(a / b)),
-            (VmConst(Int(a)), VmConst(Float(b))) => VmConst(Float(a as f64 / b)),
-            (VmConst(Float(a)), VmConst(Int(b))) => VmConst(Float(a / b as f64)),
-            (VmConst(Float(a)), VmConst(Float(b))) => VmConst(Float(a / b)),
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        })
-    }
-
-    pub fn concat_string(&mut self, mut other: Self) -> &mut Self {
-        match (self.coerce_to_string(), other.coerce_to_string()) {
-            (VmConst(Const::String(a)), VmConst(Const::String(b))) => a.push_str(b.as_str()),
-            (_, Value::Catchable(_)) => *self = other,
-            (Value::Catchable(_), _) => (),
-            _ => todo!(),
-        }
-        self
-    }
-
-    pub fn push(&mut self, elem: Self) -> &mut Self {
-        if let Value::List(list) = self {
-            Rc::make_mut(list).push(elem);
-        } else if let Value::Catchable(_) = self {
-        } else if let Value::Catchable(_) = elem {
-            *self = elem;
-        } else {
-            todo!()
-        }
-        self
-    }
-
-    pub fn concat(self, other: Self) -> Self {
-        match (self, other) {
-            (Value::List(mut a), Value::List(b)) => {
-                Rc::make_mut(&mut a).concat(b.as_ref());
-                Value::List(a)
-            }
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn push_attr(&mut self, sym: usize, val: Self) -> &mut Self {
-        if let Value::AttrSet(attrs) = self {
-            Rc::make_mut(attrs).push_attr(sym, val)
-        } else if let Value::Catchable(_) = self {
-        } else if let Value::Catchable(_) = val {
-            *self = val
-        } else {
-            todo!()
-        }
-        self
-    }
-
-    pub fn update(self, other: Self) -> Self {
-        match (self, other) {
-            (Value::AttrSet(mut a), Value::AttrSet(b)) => {
-                Rc::make_mut(&mut a).update(b.as_ref());
-                Value::AttrSet(a)
-            }
-            (x @ Value::Catchable(_), _) | (_, x @ Value::Catchable(_)) => x,
-            _ => todo!(),
-        }
-    }
-
-    pub fn select(&mut self, sym: usize, vm: &'vm VM<'_>) -> Result<&mut Self> {
-        let val = match self {
-            Value::AttrSet(attrs) => attrs
-                .select(sym)
-                .ok_or_else(|| Error::EvalError(format!("{} not found", vm.get_sym(sym)))),
-            Value::Catchable(_) => return Ok(self),
-            _ => Err(Error::EvalError(format!(
-                "cannot select from {:?}",
-                self.typename()
-            ))),
-        }?;
-        if let Value::Builtins = val {
-        } else {
-            *self = val;
-        }
-        Ok(self)
-    }
-
-    pub fn select_with_default(&mut self, sym: usize, default: Self) -> Result<&mut Self> {
-        let val = match self {
-            Value::AttrSet(attrs) => attrs.select(sym).unwrap_or(default),
-            Value::Catchable(_) => return Ok(self),
-            _ => {
-                return Err(Error::EvalError(format!(
-                    "cannot select from {:?}",
-                    self.typename()
-                )));
-            }
-        };
-        if let Value::Builtins = val {
-        } else {
-            *self = val;
-        }
-        Ok(self)
-    }
-
-    pub fn has_attr(&mut self, sym: usize) -> &mut Self {
-        if let Value::AttrSet(attrs) = self {
-            let val = VmConst(Const::Bool(attrs.has_attr(sym)));
-            *self = val;
-        } else if let Value::Catchable(_) = self {
-        } else {
-            *self = VmConst(Const::Bool(false));
-        }
-        self
-    }
-
-    pub fn coerce_to_string(&mut self) -> &mut Self {
-        if let VmConst(Const::String(_)) = self {
-        } else if let Value::Catchable(_) = self {
-        } else {
-            todo!()
-        }
-        self
-    }
-
-    pub fn force(&mut self, vm: &'vm VM<'_>) -> Result<&mut Self> {
-        if let Value::Thunk(thunk) = self {
-            let value = thunk.force(vm)?;
-            *self = value
-        } else if let Value::ThunkRef(thunk) = self {
-            let value = thunk.force(vm)?;
-            *self = value
-        }
-        Ok(self)
-    }
-
-    pub fn force_deep(&mut self, vm: &'vm VM<'_>) -> Result<&mut Self> {
-        match self {
-            Value::Thunk(thunk) => {
-                let mut value = thunk.force(vm)?;
-                let _ = value.force_deep(vm)?;
-                *self = value;
-            }
-            Value::ThunkRef(thunk) => {
-                let mut value = thunk.force(vm)?;
-                let _ = value.force_deep(vm)?;
-                *self = value;
-            }
-            Value::List(list) => Rc::make_mut(list).force_deep(vm)?,
-            Value::AttrSet(attrs) => Rc::make_mut(attrs).force_deep(vm)?,
-            _ => (),
-        }
-        Ok(self)
-    }
-
-    pub fn to_public(&self, vm: &'vm VM, seen: &mut HashSet<Value<'vm>>) -> p::Value {
-        use self::Value::*;
-        use p::Value;
-        if seen.contains(self) {
-            return Value::Repeated;
-        }
-        seen.insert(self.clone());
-        match self {
-            AttrSet(attrs) => attrs.to_public(vm, seen),
-            List(list) => list.to_public(vm, seen),
-            Catchable(catchable) => Value::Catchable(catchable.clone()),
-            Const(cnst) => Value::Const(cnst.clone().into()),
-            Thunk(_) => Value::Thunk,
-            ThunkRef(_) => Value::Thunk,
-            PrimOp(primop) => Value::PrimOp(primop.name),
-            PartialPrimOp(primop) => Value::PartialPrimOp(primop.name),
-            Func(_) => Value::Func,
-            Builtins => Value::Repeated,
-        }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct Thunk<'vm> {
-    pub thunk: RefCell<_Thunk<'vm>>,
-}
-
-#[derive(Debug, IsVariant, Unwrap, Clone)]
-pub enum _Thunk<'vm> {
-    Code(&'vm OpCodes, OnceCell<Env<'vm>>),
-    SuspendedFrom(*const Thunk<'vm>),
-    Value(Value<'vm>),
-}
-
-impl<'vm> Thunk<'vm> {
-    pub fn new(opcodes: &'vm OpCodes) -> Self {
-        Thunk {
-            thunk: RefCell::new(_Thunk::Code(opcodes, OnceCell::new())),
-        }
-    }
-
-    pub fn capture(&self, env: Env<'vm>) {
-        if let _Thunk::Code(_, envcell) = &*self.thunk.borrow() {
-            envcell.get_or_init(|| env);
-        }
-    }
-
-    pub fn force(&self, vm: &'vm VM<'_>) -> Result<Value<'vm>> {
-        match &*self.thunk.borrow() {
-            _Thunk::Value(value) => return Ok(value.clone()),
-            _Thunk::SuspendedFrom(from) => {
-                return Err(Error::EvalError(format!(
-                    "thunk {:p} already suspended from {from:p} (infinite recursion encountered)",
-                    self as *const Thunk
-                )));
-            }
-            _Thunk::Code(..) => (),
-        }
-        let (opcodes, env) = std::mem::replace(
-            &mut *self.thunk.borrow_mut(),
-            _Thunk::SuspendedFrom(self as *const Thunk),
-        )
-        .unwrap_code();
-        let value = vm.eval(opcodes.iter().copied(), env.get().unwrap().clone())?;
-        let _ = std::mem::replace(
-            &mut *self.thunk.borrow_mut(),
-            _Thunk::Value(value.clone().into()),
-        );
-        Ok(value)
-    }
-
-    pub fn value(&'vm self) -> Option<Value<'vm>> {
-        match &*self.thunk.borrow() {
-            _Thunk::Value(value) => Some(value.clone()),
-            _ => None,
-        }
-    }
-}
-
-impl PartialEq for Thunk<'_> {
-    fn eq(&self, _: &Self) -> bool {
-        false
-    }
-}

src/ty/internal/primop.rs

@@ -1,74 +0,0 @@
-use std::rc::Rc;
-
-use derive_more::Constructor;
-
-use crate::error::Result;
-use crate::vm::VM;
-
-use super::Value;
-
-#[derive(Debug, Clone, Constructor)]
-pub struct PrimOp<'vm> {
-    pub name: &'static str,
-    arity: usize,
-    func: fn(&'vm VM<'_>, Vec<Value<'vm>>) -> Result<Value<'vm>>,
-}
-
-impl PartialEq for PrimOp<'_> {
-    fn eq(&self, _: &Self) -> bool {
-        false
-    }
-}
-
-impl<'vm> PrimOp<'vm> {
-    pub fn call(&self, vm: &'vm VM<'_>, args: Vec<Value<'vm>>) -> Result<Value<'vm>> {
-        if (args.len()) < self.arity {
-            Value::PartialPrimOp(
-                PartialPrimOp {
-                    name: self.name,
-                    arity: self.arity - args.len(),
-                    args,
-                    func: self.func,
-                }
-                .into(),
-            )
-            .ok()
-        } else if args.len() == self.arity {
-            (self.func)(vm, args)
-        } else {
-            unimplemented!()
-        }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct PartialPrimOp<'vm> {
-    pub name: &'static str,
-    arity: usize,
-    args: Vec<Value<'vm>>,
-    func: fn(&'vm VM<'_>, Vec<Value<'vm>>) -> Result<Value<'vm>>,
-}
-
-impl PartialEq for PartialPrimOp<'_> {
-    fn eq(&self, _: &Self) -> bool {
-        false
-    }
-}
-
-impl<'vm> PartialPrimOp<'vm> {
-    pub fn call(self: &Rc<Self>, vm: &'vm VM<'_>, args: Vec<Value<'vm>>) -> Result<Value<'vm>> {
-        let len = args.len();
-        let mut self_clone = self.clone();
-        let self_mut = Rc::make_mut(&mut self_clone);
-        self_mut.args.extend(args);
-        self_mut.arity -= len;
-        if self_mut.arity > 0 {
-            Value::PartialPrimOp(self_clone).ok()
-        } else if self_mut.arity == 0 {
-            let args = std::mem::replace(&mut self_mut.args, Vec::new());
-            (self.func)(vm, args)
-        } else {
-            unimplemented!()
-        }
-    }
-}

src/ty/internal/string.rs

@@ -1,30 +0,0 @@
-// TODO: Contextful String
-
-use ecow::EcoString;
-use rpds::List;
-
-pub struct StringContext {
-    context: List<()>,
-}
-
-impl StringContext {
-    pub fn new() -> StringContext {
-        StringContext {
-            context: List::new(),
-        }
-    }
-}
-
-pub struct ContextfulString {
-    string: EcoString,
-    context: StringContext,
-}
-
-impl ContextfulString {
-    pub fn new(string: EcoString) -> ContextfulString {
-        ContextfulString {
-            string,
-            context: StringContext::new(),
-        }
-    }
-}

src/ty/mod.rs

@@ -1,3 +0,0 @@
-pub mod common;
-pub mod internal;
-pub mod public;

src/ty/public/cnst.rs

@@ -1,137 +0,0 @@
-use std::fmt::{Display, Formatter, Result as FmtResult};
-
-use derive_more::{IsVariant, Unwrap};
-use ecow::EcoString;
-
-use crate::error::Error;
-
-use super::super::internal as i;
-
-#[derive(Debug, Clone, IsVariant, Unwrap)]
-pub enum Const {
-    Bool(bool),
-    Int(i64),
-    Float(f64),
-    String(EcoString),
-    Null,
-}
-
-impl Display for Const {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        use Const::*;
-        match self {
-            Bool(b) => write!(f, "{b}"),
-            Int(i) => write!(f, "{i}"),
-            Float(float) => write!(f, "{float}"),
-            String(s) => write!(f, "{s}"),
-            Null => write!(f, "null"),
-        }
-    }
-}
-
-impl From<i::Const> for Const {
-    fn from(value: i::Const) -> Self {
-        use i::Const::*;
-        match value {
-            Bool(bool) => Const::Bool(bool),
-            Int(int) => Const::Int(int),
-            Float(float) => Const::Float(float),
-            String(string) => Const::String(string),
-            Null => Const::Null,
-        }
-    }
-}
-
-impl From<bool> for Const {
-    fn from(value: bool) -> Self {
-        Const::Bool(value)
-    }
-}
-
-impl From<i64> for Const {
-    fn from(value: i64) -> Self {
-        Const::Int(value)
-    }
-}
-
-impl From<f64> for Const {
-    fn from(value: f64) -> Self {
-        Const::Float(value)
-    }
-}
-
-impl From<EcoString> for Const {
-    fn from(value: EcoString) -> Self {
-        Const::String(value)
-    }
-}
-
-impl From<String> for Const {
-    fn from(value: String) -> Self {
-        Const::String(value.into())
-    }
-}
-
-impl From<&str> for Const {
-    fn from(value: &str) -> Self {
-        Const::String(value.into())
-    }
-}
-
-impl<'a> TryFrom<&'a Const> for &'a bool {
-    type Error = Error;
-
-    fn try_from(value: &'a Const) -> Result<Self, Self::Error> {
-        match value {
-            Const::Bool(b) => Ok(b),
-            _ => panic!(),
-        }
-    }
-}
-impl<'a> TryFrom<&'a Const> for &'a i64 {
-    type Error = Error;
-
-    fn try_from(value: &'a Const) -> Result<Self, Self::Error> {
-        match value {
-            Const::Int(int) => Ok(int),
-            _ => panic!(),
-        }
-    }
-}
-
-impl<'a> TryFrom<&'a Const> for &'a f64 {
-    type Error = Error;
-
-    fn try_from(value: &'a Const) -> Result<Self, Self::Error> {
-        match value {
-            Const::Float(float) => Ok(float),
-            _ => panic!(),
-        }
-    }
-}
-
-impl<'a> TryFrom<&'a Const> for &'a str {
-    type Error = Error;
-
-    fn try_from(value: &'a Const) -> Result<Self, Self::Error> {
-        match value {
-            Const::String(string) => Ok(string),
-            _ => panic!(),
-        }
-    }
-}
-
-impl PartialEq for Const {
-    fn eq(&self, other: &Self) -> bool {
-        use Const::*;
-        match (self, other) {
-            (Bool(a), Bool(b)) => a == b,
-            (Int(a), Int(b)) => a == b,
-            (Float(a), Float(b)) => a == b,
-            (String(a), String(b)) => a == b,
-            _ => false,
-        }
-    }
-}
-
-impl Eq for Const {}

src/ty/public/mod.rs

@@ -1,134 +0,0 @@
-use hashbrown::HashMap;
-use std::fmt::{Debug, Display, Formatter, Result as FmtResult};
-use std::ops::Deref;
-use std::sync::LazyLock;
-
-use derive_more::{Constructor, IsVariant, Unwrap};
-use ecow::EcoString;
-use regex::Regex;
-use rpds::VectorSync;
-
-use super::common::*;
-
-mod cnst;
-
-pub use cnst::Const;
-
-#[derive(Debug, Clone, Hash, PartialEq, Eq, PartialOrd, Ord, Constructor)]
-pub struct Symbol(EcoString);
-
-impl<T: Into<EcoString>> From<T> for Symbol {
-    fn from(value: T) -> Self {
-        Symbol(value.into())
-    }
-}
-
-impl Display for Symbol {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        if self.normal() {
-            write!(f, r#""{}""#, self.0)
-        } else {
-            write!(f, "{}", self.0)
-        }
-    }
-}
-
-static REGEX: LazyLock<Regex> =
-    LazyLock::new(|| Regex::new(r#"^[a-zA-Z\_][a-zA-Z0-9\_\'\-]*$"#).unwrap());
-impl Symbol {
-    fn normal(&self) -> bool {
-        !REGEX.is_match(self)
-    }
-}
-
-impl Deref for Symbol {
-    type Target = str;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl Symbol {
-    pub fn into_inner(self) -> EcoString {
-        self.0
-    }
-
-    pub fn as_inner(&self) -> &EcoString {
-        &self.0
-    }
-}
-
-#[derive(Constructor, Clone, PartialEq)]
-pub struct AttrSet {
-    data: HashMap<Symbol, Value>,
-}
-
-impl Debug for AttrSet {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        use Value::*;
-        write!(f, "{{ ")?;
-        for (k, v) in self.data.iter() {
-            match v {
-                List(_) => write!(f, "{k:?} = [ ... ]; ")?,
-                AttrSet(_) => write!(f, "{k:?} = {{ ... }}; ")?,
-                v => write!(f, "{k:?} = {v:?}; ")?,
-            }
-        }
-        write!(f, "}}")
-    }
-}
-
-impl Display for AttrSet {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        write!(f, "{{ ")?;
-        for (k, v) in self.data.iter() {
-            write!(f, "{k} = {v}; ")?;
-        }
-        write!(f, "}}")
-    }
-}
-
-#[derive(Constructor, Clone, Debug, PartialEq)]
-pub struct List {
-    data: VectorSync<Value>,
-}
-
-impl Display for List {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        write!(f, "[ ")?;
-        for v in self.data.iter() {
-            write!(f, "{v} ")?;
-        }
-        write!(f, "]")
-    }
-}
-
-#[derive(IsVariant, Unwrap, Clone, Debug, PartialEq)]
-pub enum Value {
-    Const(Const),
-    AttrSet(AttrSet),
-    List(List),
-    Catchable(Catchable),
-    Thunk,
-    Func,
-    PrimOp(&'static str),
-    PartialPrimOp(&'static str),
-    Repeated,
-}
-
-impl Display for Value {
-    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        use Value::*;
-        match self {
-            Const(x) => write!(f, "{x}"),
-            AttrSet(x) => write!(f, "{x}"),
-            List(x) => write!(f, "{x}"),
-            Catchable(x) => write!(f, "{x}"),
-            Thunk => write!(f, "<CODE>"),
-            Func => write!(f, "<LAMBDA>"),
-            PrimOp(x) => write!(f, "<PRIMOP {x}>"),
-            PartialPrimOp(x) => write!(f, "<PARTIAL PRIMOP {x}>"),
-            Repeated => write!(f, "<REPEATED>"),
-        }
-    }
-}

src/vm/env.rs

@@ -1,69 +0,0 @@
-use hashbrown::HashMap;
-use std::rc::Rc;
-
-use crate::ty::internal::{AttrSet, Value};
-
-#[derive(Debug, Default, Clone)]
-pub struct Env<'vm> {
-    last: Option<Rc<Env<'vm>>>,
-    map: Rc<HashMap<usize, Value<'vm>>>,
-}
-
-impl<'vm> Env<'vm> {
-    pub fn empty() -> Self {
-        Env::default()
-    }
-
-    pub fn lookup(&self, symbol: usize) -> Option<Value<'vm>> {
-        if let Some(val) = self.map.get(&symbol).cloned() {
-            return Some(val);
-        }
-        self.last.as_ref().map(|env| env.lookup(symbol)).flatten()
-    }
-
-    pub fn insert(&mut self, symbol: usize, value: Value<'vm>) {
-        Rc::make_mut(&mut self.map).insert(symbol, value);
-    }
-
-    pub fn enter(self, new: impl Iterator<Item = (usize, Value<'vm>)>) -> Self {
-        let map = Rc::new(new.collect());
-        let last = Some(
-            Env {
-                last: self.last,
-                map: self.map,
-            }
-            .into(),
-        );
-        Env { last, map }
-    }
-
-    pub fn enter_with(self, new: Rc<AttrSet<'vm>>) -> Self {
-        let map = Rc::new(
-            new.as_inner()
-                .iter()
-                .map(|(&k, v)| {
-                    (
-                        k,
-                        if let Value::Builtins = v {
-                            Value::AttrSet(new.clone())
-                        } else {
-                            v.clone()
-                        },
-                    )
-                })
-                .collect(),
-        );
-        let last = Some(
-            Env {
-                last: self.last.clone(),
-                map: self.map.clone(),
-            }
-            .into(),
-        );
-        Env { last, map }
-    }
-
-    pub fn leave(self) -> Self {
-        self.last.unwrap().as_ref().clone()
-    }
-}

src/vm/jit.rs

@@ -1,78 +0,0 @@
-use std::pin::Pin;
-
-use inkwell::builder::Builder;
-use inkwell::context::Context;
-use inkwell::execution_engine::ExecutionEngine;
-use inkwell::module::Module;
-use inkwell::types::{BasicType, BasicTypeEnum, FunctionType, StructType};
-use inkwell::values::{BasicValueEnum, FunctionValue, IntValue};
-use inkwell::{AddressSpace, OptimizationLevel};
-
-use crate::stack::Stack;
-
-use super::STACK_SIZE;
-
-#[repr(usize)]
-pub enum ValueTag {
-    Int,
-    String,
-    Bool,
-    AttrSet,
-    List,
-    Function,
-    Thunk,
-    Path,
-}
-
-#[repr(C)]
-pub struct JITValue {
-    tag: ValueTag,
-    data: u64,
-}
-
-pub struct JITContext<'ctx> {
-    context: &'ctx Context,
-    module: Module<'ctx>,
-    builder: Builder<'ctx>,
-    execution_engine: ExecutionEngine<'ctx>,
-    stack: Stack<BasicValueEnum<'ctx>, STACK_SIZE>,
-    cur_func: Option<FunctionValue<'ctx>>,
-
-    value_type: StructType<'ctx>,
-    func_type: FunctionType<'ctx>,
-}
-
-impl<'ctx> JITContext<'ctx> {
-    pub fn new(context: &'ctx Context) -> Pin<Box<Self>> {
-        let module = context.create_module("nixjit");
-        let stack = Stack::new();
-
-        let int_type = context.i64_type();
-        let pointer_type = context.ptr_type(AddressSpace::default());
-        let value_type = context.struct_type(&[int_type.into(), int_type.into()], false);
-        let func_type = value_type.fn_type(
-            &[pointer_type.into(), pointer_type.into(), value_type.into()],
-            false,
-        );
-
-        Pin::new(Box::new(JITContext {
-            execution_engine: module
-                .create_jit_execution_engine(OptimizationLevel::Default)
-                .unwrap(),
-            builder: context.create_builder(),
-            context,
-            module,
-            stack,
-            cur_func: None,
-
-            value_type,
-            func_type,
-        }))
-    }
-
-    fn new_int(&self, int: i64) -> IntValue {
-        self.context.i64_type().const_int(int as u64, false)
-    }
-
-    pub fn start_trace(&mut self) {}
-}

src/vm/mod.rs

@@ -1,267 +0,0 @@
-use hashbrown::{HashMap, HashSet};
-use std::cell::RefCell;
-use std::pin::Pin;
-
-use crate::builtins::env;
-use crate::bytecode::{BinOp, Func as F, OpCode, OpCodes, Program, UnOp};
-use crate::error::*;
-use crate::ty::internal::*;
-use crate::ty::public::{self as p, Symbol};
-
-use crate::stack::Stack;
-
-use derive_more::Constructor;
-use ecow::EcoString;
-pub use env::Env;
-pub use jit::JITContext;
-
-mod env;
-mod jit;
-
-#[cfg(test)]
-mod test;
-
-pub const STACK_SIZE: usize = 8 * 1024 / size_of::<Value>();
-
-pub fn run(prog: Program, jit: Pin<Box<JITContext<'_>>>) -> Result<p::Value> {
-    let vm = VM::new(
-        prog.thunks,
-        prog.funcs,
-        RefCell::new(prog.symbols),
-        RefCell::new(prog.symmap),
-        prog.consts,
-        jit,
-    );
-    let env = env(&vm);
-    let mut seen = HashSet::new();
-    let value = vm
-        .eval(prog.top_level.into_iter(), env)?
-        .to_public(&vm, &mut seen);
-    Ok(value)
-}
-
-#[derive(Constructor)]
-pub struct VM<'jit> {
-    thunks: Box<[OpCodes]>,
-    funcs: Box<[F]>,
-    symbols: RefCell<Vec<EcoString>>,
-    symmap: RefCell<HashMap<EcoString, usize>>,
-    consts: Box<[Const]>,
-    jit: Pin<Box<JITContext<'jit>>>,
-}
-
-impl<'vm, 'jit: 'vm> VM<'jit> {
-    pub fn get_thunk(&self, idx: usize) -> &OpCodes {
-        &self.thunks[idx]
-    }
-
-    pub fn get_func(&self, idx: usize) -> &F {
-        &self.funcs[idx]
-    }
-
-    pub fn get_sym(&self, idx: usize) -> Symbol {
-        self.symbols.borrow()[idx].clone().into()
-    }
-
-    pub fn new_sym(&self, sym: impl Into<EcoString>) -> usize {
-        let sym = sym.into();
-        if let Some(&idx) = self.symmap.borrow().get(&sym) {
-            idx
-        } else {
-            self.symmap
-                .borrow_mut()
-                .insert(sym.clone(), self.symbols.borrow().len());
-            self.symbols.borrow_mut().push(sym);
-            self.symbols.borrow().len() - 1
-        }
-    }
-
-    pub fn eval(
-        &'vm self,
-        opcodes: impl Iterator<Item = OpCode>,
-        mut env: Env<'vm>,
-    ) -> Result<Value<'vm>> {
-        let mut stack = Stack::<_, STACK_SIZE>::new();
-        let mut iter = opcodes.into_iter();
-        while let Some(opcode) = iter.next() {
-            let jmp = self.single_op(opcode, &mut stack, &mut env)?;
-            for _ in 0..jmp {
-                iter.next().unwrap();
-            }
-        }
-        assert_eq!(stack.len(), 1);
-        let mut ret = stack.pop();
-        ret.force(self)?;
-        Ok(ret)
-    }
-
-    #[inline(always)]
-    fn single_op<'s, const CAP: usize>(
-        &'vm self,
-        opcode: OpCode,
-        stack: &'s mut Stack<Value<'vm>, CAP>,
-        env: &mut Env<'vm>,
-    ) -> Result<usize> {
-        match opcode {
-            OpCode::Illegal => panic!("illegal opcode"),
-            OpCode::Const { idx } => stack.push(Value::Const(self.consts[idx].clone()))?,
-            OpCode::LoadThunk { idx } => {
-                stack.push(Value::Thunk(Thunk::new(self.get_thunk(idx)).into()))?
-            }
-            OpCode::CaptureEnv => match stack.tos()? {
-                Value::Thunk(thunk) => thunk.capture(env.clone()),
-                _ => (),
-            },
-            OpCode::ForceValue => {
-                stack.tos_mut()?.force(self)?;
-            }
-            OpCode::Jmp { step } => return Ok(step),
-            OpCode::JmpIfTrue { step } => {
-                if let Value::Const(Const::Bool(true)) = stack.pop() {
-                    return Ok(step);
-                }
-            }
-            OpCode::JmpIfFalse { step } => {
-                if let Value::Const(Const::Bool(false)) = stack.pop() {
-                    return Ok(step);
-                }
-            }
-            OpCode::Call { arity } => {
-                let mut args = Vec::with_capacity(arity);
-                for _ in 0..arity {
-                    args.insert(0, stack.pop());
-                }
-                let mut func = stack.pop();
-                func.force(self)?;
-                stack.push(func.call(self, args)?)?;
-            }
-            OpCode::Func { idx } => {
-                let func = self.get_func(idx);
-                stack.push(Value::Func(Func::new(func, env.clone(), None).into()))?;
-            }
-            OpCode::UnOp { op } => {
-                use UnOp::*;
-                let mut value = stack.pop();
-                value.force(self)?;
-                stack.push(match op {
-                    Neg => value.neg(),
-                    Not => value.not(),
-                })?;
-            }
-            OpCode::BinOp { op } => {
-                use BinOp::*;
-                let mut rhs = stack.pop();
-                let mut lhs = stack.pop();
-                lhs.force(self)?;
-                rhs.force(self)?;
-                stack.push(match op {
-                    Add => lhs.add(rhs),
-                    Sub => lhs.add(rhs.neg()),
-                    Mul => lhs.mul(rhs),
-                    Div => lhs.div(rhs)?,
-                    And => lhs.and(rhs),
-                    Or => lhs.or(rhs),
-                    Eq => lhs.eq(rhs, self),
-                    Lt => lhs.lt(rhs),
-                    Con => lhs.concat(rhs),
-                    Upd => lhs.update(rhs),
-                })?;
-            }
-            OpCode::ConcatString => {
-                let mut rhs = stack.pop();
-                rhs.force(self)?;
-                stack.tos_mut()?.concat_string(rhs);
-            }
-            OpCode::Path => {
-                todo!()
-            }
-            OpCode::List => {
-                stack.push(Value::List(List::empty().into()))?;
-            }
-            OpCode::PushElem => {
-                let elem = stack.pop();
-                stack.tos_mut()?.push(elem);
-            }
-            OpCode::AttrSet { cap } => {
-                stack.push(Value::AttrSet(AttrSet::with_capacity(cap).into()))?;
-            }
-            OpCode::FinalizeRec => {
-                let env = env.clone().enter(
-                    stack
-                        .tos()?
-                        .clone()
-                        .unwrap_attr_set()
-                        .as_inner()
-                        .iter()
-                        .map(|(k, v)| (k.clone(), v.clone())),
-                );
-                stack.tos_mut()?.as_mut().unwrap_attr_set().capture(&env);
-            }
-            OpCode::PushStaticAttr { name } => {
-                let val = stack.pop();
-                stack.tos_mut()?.push_attr(name, val);
-            }
-            OpCode::PushDynamicAttr => {
-                let val = stack.pop();
-                let mut sym = stack.pop();
-                sym.force(self)?.coerce_to_string();
-                let sym = self.new_sym(sym.unwrap_const().unwrap_string());
-                stack.tos_mut()?.push_attr(sym, val);
-            }
-            OpCode::Select { sym } => {
-                stack.tos_mut()?.force(self)?.select(sym, self)?;
-            }
-            OpCode::SelectOrDefault { sym } => {
-                let default = stack.pop();
-                stack
-                    .tos_mut()?
-                    .force(self)?
-                    .select_with_default(sym, default)?;
-            }
-            OpCode::SelectDynamic => {
-                let mut val = stack.pop();
-                val.force(self)?;
-                val.coerce_to_string();
-                let sym = self.new_sym(val.unwrap_const().unwrap_string());
-                stack.tos_mut()?.force(self)?.select(sym, self)?;
-            }
-            OpCode::SelectDynamicOrDefault => {
-                let default = stack.pop();
-                let mut val = stack.pop();
-                val.force(self)?;
-                val.coerce_to_string();
-                let sym = self.new_sym(val.unwrap_const().unwrap_string());
-                stack
-                    .tos_mut()?
-                    .force(self)?
-                    .select_with_default(sym, default)?;
-            }
-            OpCode::HasAttr { sym } => {
-                stack.tos_mut()?.force(self)?.has_attr(sym);
-            }
-            OpCode::HasDynamicAttr => {
-                let mut val = stack.pop();
-                val.coerce_to_string();
-                let sym = self.new_sym(val.unwrap_const().unwrap_string());
-                stack.tos_mut()?.force(self)?.has_attr(sym);
-            }
-            OpCode::LookUp { sym } => {
-                stack.push(env.lookup(sym).ok_or_else(|| {
-                    Error::EvalError(format!("{} not found", self.get_sym(sym)))
-                })?)?;
-            }
-            OpCode::EnterEnv => match stack.pop() {
-                Value::AttrSet(attrs) => *env = env.clone().enter_with(attrs),
-
-                _ => unreachable!(),
-            },
-            OpCode::LeaveEnv => *env = env.clone().leave(),
-            OpCode::Assert => {
-                if !stack.pop().unwrap_const().unwrap_bool() {
-                    todo!()
-                }
-            }
-        }
-        Ok(0)
-    }
-}