refactor: flatten Ir::Const & Value::Const; add Ir::Builtin to represent

globally available builtins

nix-js/src/codegen.rs

@@ -2,11 +2,11 @@ use itertools::Itertools as _;
 
 use crate::ir::*;
 
-pub trait Compile<Ctx: CodegenContext> {
+pub(crate) trait Compile<Ctx: CodegenContext> {
     fn compile(&self, ctx: &Ctx) -> String;
 }
 
-pub trait CodegenContext {
+pub(crate) trait CodegenContext {
     fn get_ir(&self, id: ExprId) -> &Ir;
     fn get_sym(&self, id: SymId) -> &str;
 }
@@ -14,12 +14,8 @@ pub trait CodegenContext {
 impl<Ctx: CodegenContext> Compile<Ctx> for Ir {
     fn compile(&self, ctx: &Ctx) -> String {
         match self {
-            Ir::Const(Const { val }) => match val {
+            Ir::Int(int) => format!("{int}n"), // Generate BigInt literal
-                crate::value::Const::Null => "null".to_string(),
+            Ir::Float(float) => float.to_string(),
-                crate::value::Const::Int(val) => format!("{}n", val), // Generate BigInt literal
-                crate::value::Const::Float(val) => val.to_string(),
-                crate::value::Const::Bool(val) => val.to_string(),
-            },
             Ir::Str(s) => {
                 // Escape string for JavaScript
                 let escaped = s
@@ -63,6 +59,7 @@ impl<Ctx: CodegenContext> Compile<Ctx> for Ir {
                 format!("expr{}", expr_id.0)
             }
             Ir::Builtins(_) => "Nix.builtins".to_string(),
+            &Ir::Builtin(Builtin(name)) => format!("Nix.builtins[\"{}\"]", ctx.get_sym(name)),
             Ir::ConcatStrings(x) => x.compile(ctx),
             Ir::HasAttr(x) => x.compile(ctx),
             &Ir::Assert(Assert { assertion, expr }) => {

nix-js/src/context.rs

@@ -8,7 +8,7 @@ use string_interner::DefaultStringInterner;
 
 use crate::codegen::{CodegenContext, Compile};
 use crate::error::{Error, Result};
-use crate::ir::{DowngradeContext, ExprId, Ir, SymId};
+use crate::ir::{Builtin, DowngradeContext, ExprId, Ir, SymId};
 use crate::runtime::Runtime;
 use crate::value::Value;
 
@@ -118,7 +118,7 @@ impl Drop for PathDropGuard<'_> {
 
 impl Default for Ctx {
     fn default() -> Self {
-        use crate::ir::{Attr, Builtins, Select, ToIr};
+        use crate::ir::{Builtins, ToIr as _};
 
         let mut symbols = DefaultStringInterner::new();
         let mut irs = Vec::new();
@@ -157,14 +157,9 @@ impl Default for Ctx {
 
         for name in free_globals {
             let name_sym = symbols.get_or_intern(name);
-            let select_ir = Select {
+            let id = ExprId(irs.len());
-                expr: builtins_expr,
+            irs.push(Builtin(name_sym).to_ir());
-                attrpath: vec![Attr::Str(name_sym)],
+            global.insert(name_sym, id);
-                default: None,
-            };
-            let select_expr = ExprId(irs.len());
-            irs.push(select_ir.to_ir());
-            global.insert(name_sym, select_expr);
         }
 
         Self {
@@ -178,16 +173,16 @@ impl Default for Ctx {
 }
 
 impl Ctx {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         Self::default()
     }
 
-    pub fn downgrade_ctx<'a>(self: Pin<&'a mut Self>) -> DowngradeCtx<'a> {
+    pub(crate) fn downgrade_ctx<'a>(self: Pin<&'a mut Self>) -> DowngradeCtx<'a> {
         let global_ref = unsafe { self.global.as_ref() };
         DowngradeCtx::new(self, global_ref)
     }
 
-    pub fn get_current_dir(&self) -> PathBuf {
+    pub(crate) fn get_current_dir(&self) -> PathBuf {
         self.path_stack
             .last()
             .unwrap()
@@ -212,63 +207,55 @@ mod test {
     use std::collections::BTreeMap;
 
     use super::*;
-    use crate::value::{AttrSet, Const, List, Symbol};
+    use crate::value::{AttrSet, List, Symbol};
 
     #[test]
     fn basic_eval() {
-        assert_eq!(
+        assert_eq!(Context::new().eval_code("1 + 1").unwrap(), Value::Int(2));
-            Context::new().eval_code("1 + 1").unwrap(),
+        assert_eq!(Context::new().eval_code("(x: x) 1").unwrap(), Value::Int(1));
-            Value::Const(Const::Int(2))
-        );
-        assert_eq!(
-            Context::new().eval_code("(x: x) 1").unwrap(),
-            Value::Const(Const::Int(1))
-        );
         assert_eq!(
             Context::new().eval_code("(x: y: x - y) 2 1").unwrap(),
-            Value::Const(Const::Int(1))
+            Value::Int(1)
         );
         assert_eq!(
             Context::new().eval_code("rec { b = a; a = 1; }.b").unwrap(),
-            Value::Const(Const::Int(1))
+            Value::Int(1)
         );
         assert_eq!(
             Context::new().eval_code("let b = a; a = 1; in b").unwrap(),
-            Value::Const(Const::Int(1))
+            Value::Int(1)
         );
         assert_eq!(
             Context::new().eval_code("let fib = n: if n == 1 || n == 2 then 1 else (fib (n - 1)) + (fib (n - 2)); in fib 30").unwrap(),
-            Value::Const(Const::Int(832040))
+            Value::Int(832040)
         );
         assert_eq!(
             Context::new()
                 .eval_code("((f: let x = f x; in x)(self: { x = 1; y = self.x + 1; })).y")
                 .unwrap(),
-            Value::Const(Const::Int(2))
+            Value::Int(2)
         );
     }
 
     #[test]
     fn test_binop() {
         let tests = [
-            ("1 + 1", Value::Const(Const::Int(2))),
+            ("1 + 1", Value::Int(2)),
-            ("2 - 1", Value::Const(Const::Int(1))),
+            ("2 - 1", Value::Int(1)),
-            ("1. * 1", Value::Const(Const::Float(1.))),
+            ("1. * 1", Value::Float(1.)),
-            ("1 / 1.", Value::Const(Const::Float(1.))),
+            ("1 / 1.", Value::Float(1.)),
-            ("1 == 1", Value::Const(Const::Bool(true))),
+            ("1 == 1", Value::Bool(true)),
-            ("1 != 1", Value::Const(Const::Bool(false))),
+            ("1 != 1", Value::Bool(false)),
-            ("2 < 1", Value::Const(Const::Bool(false))),
+            ("2 < 1", Value::Bool(false)),
-            ("2 > 1", Value::Const(Const::Bool(true))),
+            ("2 > 1", Value::Bool(true)),
-            ("1 <= 1", Value::Const(Const::Bool(true))),
+            ("1 <= 1", Value::Bool(true)),
-            ("1 >= 1", Value::Const(Const::Bool(true))),
+            ("1 >= 1", Value::Bool(true)),
             // Short-circuit evaluation: true || <expr> should not evaluate <expr>
-            ("true || (1 / 0)", Value::Const(Const::Bool(true))),
+            ("true || (1 / 0)", Value::Bool(true)),
-            ("true && 1 == 0", Value::Const(Const::Bool(false))),
+            ("true && 1 == 0", Value::Bool(false)),
             (
                 "[ 1 2 3 ] ++ [ 4 5 6 ]",
-                Value::List(List::new(
+                Value::List(List::new((1..=6).map(Value::Int).collect())),
-                    (1..=6).map(Const::Int).map(Value::Const).collect(),
-                )),
             ),
             (
                 "{ a.b = 1; b = 2; } // { a.c = 2; }",
@@ -277,10 +264,10 @@ mod test {
                         Symbol::from("a"),
                         Value::AttrSet(AttrSet::new(BTreeMap::from([(
                             Symbol::from("c"),
-                            Value::Const(Const::Int(2)),
+                            Value::Int(2),
                         )]))),
                     ),
-                    (Symbol::from("b"), Value::Const(Const::Int(2))),
+                    (Symbol::from("b"), Value::Int(2)),
                 ]))),
             ),
         ];
@@ -296,7 +283,7 @@ mod test {
             Context::new()
                 .eval_code("({ a, b }: a + b) { a = 1; b = 2; }")
                 .unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
 
         // Test missing required parameter should fail
@@ -308,7 +295,7 @@ mod test {
             Context::new()
                 .eval_code("({ x, y, z }: x + y + z) { x = 1; y = 2; z = 3; }")
                 .unwrap(),
-            Value::Const(Const::Int(6))
+            Value::Int(6)
         );
     }
 
@@ -323,7 +310,7 @@ mod test {
             Context::new()
                 .eval_code("({ a, b, ... }: a + b) { a = 1; b = 2; c = 3; }")
                 .unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
     }
 
@@ -334,7 +321,7 @@ mod test {
             Context::new()
                 .eval_code("({ a, b ? 5 }: a + b) { a = 1; }")
                 .unwrap(),
-            Value::Const(Const::Int(6))
+            Value::Int(6)
         );
 
         // Test overriding default parameter
@@ -342,7 +329,7 @@ mod test {
             Context::new()
                 .eval_code("({ a, b ? 5 }: a + b) { a = 1; b = 10; }")
                 .unwrap(),
-            Value::Const(Const::Int(11))
+            Value::Int(11)
         );
     }
 
@@ -353,7 +340,7 @@ mod test {
             Context::new()
                 .eval_code("(args@{ a, b }: args.a + args.b) { a = 1; b = 2; }")
                 .unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
     }
 
@@ -364,13 +351,13 @@ mod test {
             Context::new()
                 .eval_code("(x: x.a + x.b) { a = 1; b = 2; }")
                 .unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
 
         // Simple parameter accepts any argument
         assert_eq!(
             Context::new().eval_code("(x: x) 42").unwrap(),
-            Value::Const(Const::Int(42))
+            Value::Int(42)
         );
     }
 
@@ -394,7 +381,7 @@ mod test {
         // Test calling builtin function: builtins.add 1 2
         assert_eq!(
             Context::new().eval_code("builtins.add 1 2").unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
     }
 
@@ -403,7 +390,7 @@ mod test {
         // Test builtin with list: builtins.length [1 2 3]
         assert_eq!(
             Context::new().eval_code("builtins.length [1 2 3]").unwrap(),
-            Value::Const(Const::Int(3))
+            Value::Int(3)
         );
     }
 
@@ -412,11 +399,9 @@ mod test {
         // Test higher-order builtin: map (x: x * 2) [1 2 3]
         assert_eq!(
             Context::new().eval_code("map (x: x * 2) [1 2 3]").unwrap(),
-            Value::List(List::new(vec![
+            Value::List(List::new(
-                Value::Const(Const::Int(2)),
+                vec![Value::Int(2), Value::Int(4), Value::Int(6),]
-                Value::Const(Const::Int(4)),
+            ))
-                Value::Const(Const::Int(6)),
-            ]))
         );
     }
 
@@ -427,10 +412,7 @@ mod test {
             Context::new()
                 .eval_code("builtins.filter (x: x > 1) [1 2 3]")
                 .unwrap(),
-            Value::List(List::new(vec![
+            Value::List(List::new(vec![Value::Int(2), Value::Int(3),]))
-                Value::Const(Const::Int(2)),
-                Value::Const(Const::Int(3)),
-            ]))
         );
     }
 
@@ -453,7 +435,7 @@ mod test {
         // Test builtins.head [1 2 3]
         assert_eq!(
             Context::new().eval_code("builtins.head [1 2 3]").unwrap(),
-            Value::Const(Const::Int(1))
+            Value::Int(1)
         );
     }
 
@@ -462,10 +444,7 @@ mod test {
         // Test builtins.tail [1 2 3]
         assert_eq!(
             Context::new().eval_code("builtins.tail [1 2 3]").unwrap(),
-            Value::List(List::new(vec![
+            Value::List(List::new(vec![Value::Int(2), Value::Int(3),]))
-                Value::Const(Const::Int(2)),
-                Value::Const(Const::Int(3)),
-            ]))
         );
     }
 
@@ -476,7 +455,7 @@ mod test {
             Context::new()
                 .eval_code("let b = builtins; in b.add 5 3")
                 .unwrap(),
-            Value::Const(Const::Int(8))
+            Value::Int(8)
         );
     }
 
@@ -487,7 +466,7 @@ mod test {
             Context::new()
                 .eval_code("with builtins; add 10 20")
                 .unwrap(),
-            Value::Const(Const::Int(30))
+            Value::Int(30)
         );
     }
 
@@ -498,7 +477,7 @@ mod test {
             Context::new()
                 .eval_code("builtins.add (builtins.mul 2 3) (builtins.sub 10 5)")
                 .unwrap(),
-            Value::Const(Const::Int(11)) // (2*3) + (10-5) = 6 + 5 = 11
+            Value::Int(11) // (2*3) + (10-5 = 6 + 5 = 11
         );
     }
 
@@ -507,27 +486,27 @@ mod test {
         // Test type checking functions
         assert_eq!(
             Context::new().eval_code("builtins.isList [1 2 3]").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             Context::new()
                 .eval_code("builtins.isAttrs { a = 1; }")
                 .unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             Context::new()
                 .eval_code("builtins.isFunction (x: x)")
                 .unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             Context::new().eval_code("builtins.isNull null").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             Context::new().eval_code("builtins.isBool true").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
     }
 
@@ -538,7 +517,7 @@ mod test {
             Context::new()
                 .eval_code("let builtins = { add = x: y: x - y; }; in builtins.add 5 3")
                 .unwrap(),
-            Value::Const(Const::Int(2)) // Uses shadowed version
+            Value::Int(2) // Uses shadowed version
         );
     }
 
@@ -549,32 +528,26 @@ mod test {
         let result = Context::new()
             .eval_code("builtins.builtins.builtins.add 1 1")
             .unwrap();
-        assert_eq!(result, Value::Const(Const::Int(2)));
+        assert_eq!(result, Value::Int(2));
     }
 
     // Free globals tests
     #[test]
     fn test_free_global_true() {
-        assert_eq!(
+        assert_eq!(Context::new().eval_code("true").unwrap(), Value::Bool(true));
-            Context::new().eval_code("true").unwrap(),
-            Value::Const(Const::Bool(true))
-        );
     }
 
     #[test]
     fn test_free_global_false() {
         assert_eq!(
             Context::new().eval_code("false").unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
     }
 
     #[test]
     fn test_free_global_null() {
-        assert_eq!(
+        assert_eq!(Context::new().eval_code("null").unwrap(), Value::Null);
-            Context::new().eval_code("null").unwrap(),
-            Value::Const(Const::Null)
-        );
     }
 
     #[test]
@@ -582,11 +555,9 @@ mod test {
         // Test free global function: map (x: x * 2) [1 2 3]
         assert_eq!(
             Context::new().eval_code("map (x: x * 2) [1 2 3]").unwrap(),
-            Value::List(List::new(vec![
+            Value::List(List::new(
-                Value::Const(Const::Int(2)),
+                vec![Value::Int(2), Value::Int(4), Value::Int(6),]
-                Value::Const(Const::Int(4)),
+            ))
-                Value::Const(Const::Int(6)),
-            ]))
         );
     }
 
@@ -595,11 +566,11 @@ mod test {
         // Test isNull function
         assert_eq!(
             Context::new().eval_code("isNull null").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             Context::new().eval_code("isNull 5").unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
     }
 
@@ -610,13 +581,13 @@ mod test {
             Context::new()
                 .eval_code("let true = false; in true")
                 .unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
         assert_eq!(
             Context::new()
                 .eval_code("let map = x: y: x; in map 1 2")
                 .unwrap(),
-            Value::Const(Const::Int(1))
+            Value::Int(1)
         );
     }
 
@@ -627,10 +598,7 @@ mod test {
             Context::new()
                 .eval_code("if true then map (x: x + 1) [1 2] else []")
                 .unwrap(),
-            Value::List(List::new(vec![
+            Value::List(List::new(vec![Value::Int(2), Value::Int(3),]))
-                Value::Const(Const::Int(2)),
-                Value::Const(Const::Int(3)),
-            ]))
         );
     }
 
@@ -641,7 +609,7 @@ mod test {
             Context::new()
                 .eval_code("let x = true; y = false; in x && y")
                 .unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
     }
 
@@ -653,21 +621,21 @@ mod test {
         // Test large i64 values
         assert_eq!(
             ctx.eval_code("9223372036854775807").unwrap(),
-            Value::Const(Const::Int(9223372036854775807))
+            Value::Int(9223372036854775807)
         );
 
         // Test negative large value
         // Can't use -9223372036854775808 since unary minus is actually desugared to (0 - <expr>)
         assert_eq!(
             ctx.eval_code("-9223372036854775807").unwrap(),
-            Value::Const(Const::Int(-9223372036854775807))
+            Value::Int(-9223372036854775807)
         );
 
         // Test large number arithmetic
         assert_eq!(
             ctx.eval_code("5000000000000000000 + 3000000000000000000")
                 .unwrap(),
-            Value::Const(Const::Int(8000000000000000000i64))
+            Value::Int(8000000000000000000i64)
         );
     }
 
@@ -678,25 +646,25 @@ mod test {
         // isInt tests
         assert_eq!(
             ctx.eval_code("builtins.isInt 42").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             ctx.eval_code("builtins.isInt 42.0").unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
 
         // isFloat tests
         assert_eq!(
             ctx.eval_code("builtins.isFloat 42").unwrap(),
-            Value::Const(Const::Bool(false))
+            Value::Bool(false)
         );
         assert_eq!(
             ctx.eval_code("builtins.isFloat 42.5").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
         assert_eq!(
             ctx.eval_code("builtins.isFloat 1.0").unwrap(),
-            Value::Const(Const::Bool(true))
+            Value::Bool(true)
         );
 
         // typeOf tests
@@ -714,8 +682,8 @@ mod test {
         );
 
         // literal tests
-        assert_eq!(ctx.eval_code("1").unwrap(), Value::Const(Const::Int(1)));
+        assert_eq!(ctx.eval_code("1").unwrap(), Value::Int(1));
-        assert_eq!(ctx.eval_code("1.").unwrap(), Value::Const(Const::Float(1.)))
+        assert_eq!(ctx.eval_code("1.").unwrap(), Value::Float(1.))
     }
 
     #[test]
@@ -751,30 +719,18 @@ mod test {
     fn test_integer_division() {
         let mut ctx = Context::new();
 
-        assert_eq!(ctx.eval_code("5 / 2").unwrap(), Value::Const(Const::Int(2)));
+        assert_eq!(ctx.eval_code("5 / 2").unwrap(), Value::Int(2));
 
-        assert_eq!(ctx.eval_code("7 / 3").unwrap(), Value::Const(Const::Int(2)));
+        assert_eq!(ctx.eval_code("7 / 3").unwrap(), Value::Int(2));
 
-        assert_eq!(
+        assert_eq!(ctx.eval_code("10 / 3").unwrap(), Value::Int(3));
-            ctx.eval_code("10 / 3").unwrap(),
-            Value::Const(Const::Int(3))
-        );
 
         // Float division returns float
-        assert_eq!(
+        assert_eq!(ctx.eval_code("5 / 2.0").unwrap(), Value::Float(2.5));
-            ctx.eval_code("5 / 2.0").unwrap(),
-            Value::Const(Const::Float(2.5))
-        );
 
-        assert_eq!(
+        assert_eq!(ctx.eval_code("7.0 / 2").unwrap(), Value::Float(3.5));
-            ctx.eval_code("7.0 / 2").unwrap(),
-            Value::Const(Const::Float(3.5))
-        );
 
-        assert_eq!(
+        assert_eq!(ctx.eval_code("(-7) / 3").unwrap(), Value::Int(-2));
-            ctx.eval_code("(-7) / 3").unwrap(),
-            Value::Const(Const::Int(-2))
-        );
     }
 
     #[test]
@@ -785,13 +741,13 @@ mod test {
         assert_eq!(
             ctx.eval_code("builtins.add 5000000000000000000 3000000000000000000")
                 .unwrap(),
-            Value::Const(Const::Int(8000000000000000000i64))
+            Value::Int(8000000000000000000i64)
         );
 
         // Test builtin mul with large numbers
         assert_eq!(
             ctx.eval_code("builtins.mul 1000000000 1000000000").unwrap(),
-            Value::Const(Const::Int(1000000000000000000i64))
+            Value::Int(1000000000000000000i64)
         );
     }
 
@@ -805,7 +761,7 @@ mod test {
         std::fs::write(&lib_path, "{ add = a: b: a + b; }").unwrap();
 
         let expr = format!(r#"(import "{}").add 3 5"#, lib_path.display());
-        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Const(Const::Int(8)));
+        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Int(8));
     }
 
     #[test]
@@ -825,7 +781,7 @@ mod test {
         std::fs::write(&main_path, main_content).unwrap();
 
         let expr = format!(r#"(import "{}").result"#, main_path.display());
-        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Const(Const::Int(30)));
+        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Int(30));
     }
 
     #[test]
@@ -855,10 +811,10 @@ mod test {
         std::fs::write(&main_path, main_content).unwrap();
 
         let expr = format!(r#"let x = import "{}"; in x.result1"#, main_path.display());
-        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Const(Const::Int(12)));
+        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Int(12));
 
         let expr = format!(r#"let x = import "{}"; in x.result2"#, main_path.display());
-        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Const(Const::Int(7)));
+        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Int(7));
     }
 
     #[test]
@@ -870,6 +826,6 @@ mod test {
         std::fs::write(&func_path, "x: x * 2").unwrap();
 
         let expr = format!(r#"(import "{}") 5"#, func_path.display());
-        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Const(Const::Int(10)));
+        assert_eq!(ctx.eval_code(&expr).unwrap(), Value::Int(10));
     }
 }

nix-js/src/ir.rs

@@ -4,7 +4,6 @@ use rnix::ast;
 use string_interner::symbol::SymbolU32;
 
 use crate::error::{Error, Result};
-use crate::value::Const as PubConst;
 use crate::value::format_symbol;
 use nix_js_macros::ir;
 
@@ -44,8 +43,12 @@ pub trait DowngradeContext {
 ir! {
     Ir,
 
+    Int(i64),
+    Float(f64),
+    Str,
     AttrSet,
     List,
+
     HasAttr,
     BinOp,
     UnOp,
@@ -54,8 +57,6 @@ ir! {
     Call,
     Assert,
     ConcatStrings,
-    Const,
-    Str,
     Path,
     Func,
     Let,
@@ -63,6 +64,7 @@ ir! {
     ExprRef(ExprId),
     Thunk(ExprId),
     Builtins,
+    Builtin,
 }
 
 impl AttrSet {
@@ -354,18 +356,6 @@ 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 {
@@ -386,4 +376,4 @@ pub struct Builtins;
 
 /// Represents an attribute in `builtins`.
 #[derive(Debug)]
-pub struct Builtin(pub String);
+pub struct Builtin(pub SymId);

nix-js/src/ir/downgrade.rs

@@ -139,8 +139,8 @@ impl<Ctx: DowngradeContext> Downgrade<Ctx> for ast::Str {
 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_ir(),
+            ast::LiteralKind::Integer(int) => Ir::Int(int.value().unwrap()),
-            ast::LiteralKind::Float(float) => Const::from(float.value().unwrap()).to_ir(),
+            ast::LiteralKind::Float(float) => Ir::Float(float.value().unwrap()),
             ast::LiteralKind::Uri(uri) => Str {
                 val: uri.to_string(),
             }

nix-js/src/lib.rs

@@ -1,8 +1,8 @@
-pub mod codegen;
+mod codegen;
 pub mod context;
 pub mod error;
 pub mod ir;
-pub mod runtime;
+mod runtime;
 pub mod value;
 
 #[global_allocator]

nix-js/src/runtime.rs

@@ -3,13 +3,12 @@ use std::pin::Pin;
 use std::sync::Once;
 
 use deno_core::{Extension, ExtensionFileSource, JsRuntime, OpDecl, OpState, RuntimeOptions, v8};
-use deno_error::js_error_wrapper;
 
 use crate::codegen::{CodegenContext, Compile};
 use crate::context::{CtxPtr, PathDropGuard};
 use crate::error::{Error, Result};
 use crate::ir::DowngradeContext;
-use crate::value::{AttrSet, Const, List, Symbol, Value};
+use crate::value::{AttrSet, List, Symbol, Value};
 
 type ScopeRef<'p, 's> = v8::PinnedRef<'p, v8::HandleScope<'s>>;
 type LocalValue<'a> = v8::Local<'a, v8::Value>;
@@ -38,33 +37,32 @@ fn runtime_extension(ctx: CtxPtr) -> Extension {
     }
 }
 
+mod private {
+    use deno_error::js_error_wrapper;
+    #[allow(dead_code)]
     #[derive(Debug)]
-pub struct SimpleErrorWrapper(String);
+    pub struct SimpleErrorWrapper(pub(crate) String);
-
     impl std::fmt::Display for SimpleErrorWrapper {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             std::fmt::Debug::fmt(self, f)
         }
     }
-
+    impl std::error::Error for SimpleErrorWrapper {}
-impl std::error::Error for SimpleErrorWrapper {
-    fn cause(&self) -> Option<&dyn std::error::Error> {
-        None
-    }
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-        None
-    }
-    fn description(&self) -> &str {
-        &self.0
-    }
-}
 
     js_error_wrapper!(SimpleErrorWrapper, NixError, "EvalError");
+
     impl From<String> for NixError {
         fn from(value: String) -> Self {
             NixError(SimpleErrorWrapper(value))
         }
     }
+    impl From<&str> for NixError {
+        fn from(value: &str) -> Self {
+            NixError(SimpleErrorWrapper(value.to_string()))
+        }
+    }
+}
+use private::NixError;
 
 #[deno_core::op2]
 #[string]
@@ -76,14 +74,13 @@ fn op_import(state: &mut OpState, #[string] path: String) -> std::result::Result
     let absolute_path = current_dir
         .join(&path)
         .canonicalize()
-        .map_err(|e| -> NixError { format!("Failed to resolve path {}: {}", path, e).into() })?;
+        .map_err(|e| format!("Failed to resolve path {}: {}", path, e))?;
 
     let mut guard = PathDropGuard::new(absolute_path.clone(), ctx);
     let ctx = guard.as_ctx();
 
-    let content = std::fs::read_to_string(&absolute_path).map_err(|e| -> NixError {
+    let content = std::fs::read_to_string(&absolute_path)
-        format!("Failed to read {}: {}", absolute_path.display(), e).into()
+        .map_err(|e| format!("Failed to read {}: {}", absolute_path.display(), e))?;
-    })?;
 
     let root = rnix::Root::parse(&content);
     if !root.errors().is_empty() {
@@ -95,15 +92,12 @@ fn op_import(state: &mut OpState, #[string] path: String) -> std::result::Result
         .into());
     }
 
-    let expr = root
+    let expr = root.tree().expr().ok_or("No expression in file")?;
-        .tree()
-        .expr()
-        .ok_or_else(|| -> NixError { "No expression in file".to_string().into() })?;
     let expr_id = ctx
         .as_mut()
         .downgrade_ctx()
         .downgrade(expr)
-        .map_err(|e| -> NixError { format!("Downgrade error: {}", e).into() })?;
+        .map_err(|e| format!("Downgrade error: {}", e))?;
 
     Ok(ctx.get_ir(expr_id).compile(Pin::get_ref(ctx.as_ref())))
 }
@@ -111,8 +105,7 @@ fn op_import(state: &mut OpState, #[string] path: String) -> std::result::Result
 #[deno_core::op2]
 #[string]
 fn op_read_file(#[string] path: String) -> std::result::Result<String, NixError> {
-    std::fs::read_to_string(&path)
+    Ok(std::fs::read_to_string(&path).map_err(|e| format!("Failed to read {}: {}", path, e))?)
-        .map_err(|e| -> NixError { format!("Failed to read {}: {}", path, e).into() })
 }
 
 #[deno_core::op2(fast)]
@@ -137,11 +130,11 @@ fn op_resolve_path(
     // Resolve relative path against current file directory (or CWD)
     let current_dir = ctx.get_current_dir();
 
-    current_dir
+    Ok(current_dir
         .join(&path)
         .canonicalize()
         .map(|p| p.to_string_lossy().to_string())
-        .map_err(|e| -> NixError { format!("Failed to resolve path {}: {}", path, e).into() })
+        .map_err(|e| format!("Failed to resolve path {}: {}", path, e))?)
 }
 
 pub(crate) struct Runtime {
@@ -234,16 +227,16 @@ fn to_value<'a>(
             if !lossless {
                 panic!("BigInt value out of i64 range: conversion lost precision");
             }
-            Value::Const(Const::Int(val))
+            Value::Int(val)
         }
         _ if val.is_number() => {
             let val = val.to_number(scope).unwrap().value();
             // number is always NixFloat
-            Value::Const(Const::Float(val))
+            Value::Float(val)
         }
-        _ if val.is_true() => Value::Const(Const::Bool(true)),
+        _ if val.is_true() => Value::Bool(true),
-        _ if val.is_false() => Value::Const(Const::Bool(false)),
+        _ if val.is_false() => Value::Bool(false),
-        _ if val.is_null() => Value::Const(Const::Null),
+        _ if val.is_null() => Value::Null,
         _ if val.is_string() => {
             let val = val.to_string(scope).unwrap();
             Value::String(val.to_rust_string_lossy(scope))
@@ -349,10 +342,10 @@ mod test {
             Value::AttrSet(AttrSet::new(std::collections::BTreeMap::from([(
                 Symbol::from("test"),
                 Value::List(List::new(vec![
-                    Value::Const(Const::Float(1.)),
+                    Value::Float(1.),
-                    Value::Const(Const::Int(9223372036854775807)),
+                    Value::Int(9223372036854775807),
-                    Value::Const(Const::Bool(true)),
+                    Value::Bool(true),
-                    Value::Const(Const::Bool(false)),
+                    Value::Bool(false),
                     Value::String("hello world!".to_string())
                 ]))
             )])))

nix-js/src/value.rs

@@ -9,49 +9,6 @@ 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);
@@ -172,8 +129,14 @@ impl Display for List {
 /// 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).
+    /// An integer value.
-    Const(Const),
+    Int(i64),
+    /// An floating-point value.
+    Float(f64),
+    /// An boolean value.
+    Bool(bool),
+    /// An null value.
+    Null,
     /// A string value.
     String(String),
     /// An attribute set.
@@ -197,7 +160,10 @@ impl Display for Value {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
         use Value::*;
         match self {
-            Const(x) => write!(f, "{x}"),
+            &Int(x) => write!(f, "{x}"),
+            &Float(x) => write!(f, "{x}"),
+            &Bool(x) => write!(f, "{x}"),
+            Null => write!(f, "null"),
             String(x) => write!(f, r#""{x}""#),
             AttrSet(x) => write!(f, "{x}"),
             List(x) => write!(f, "{x}"),