diff --git a/nix-js/runtime-ts/src/string-context.ts b/nix-js/runtime-ts/src/string-context.ts
index 265bd0b..ead728b 100644
--- a/nix-js/runtime-ts/src/string-context.ts
+++ b/nix-js/runtime-ts/src/string-context.ts
@@ -62,28 +62,6 @@ export const mergeContexts = (...contexts: NixStringContext[]): NixStringContext
   return result;
 };
 
-export const concatStringsWithContext = (
-  strings: (string | StringWithContext)[],
-): string | StringWithContext => {
-  const parts: string[] = [];
-  const contexts: NixStringContext[] = [];
-
-  for (const s of strings) {
-    parts.push(getStringValue(s));
-    const ctx = getStringContext(s);
-    if (ctx.size > 0) {
-      contexts.push(ctx);
-    }
-  }
-
-  const value = parts.join("");
-  if (contexts.length === 0) {
-    return value;
-  }
-
-  return mkStringWithContext(value, mergeContexts(...contexts));
-};
-
 export const encodeContextElem = (elem: StringContextElem): string => {
   switch (elem.type) {
     case "opaque":
diff --git a/nix-js/src/codegen.rs b/nix-js/src/codegen.rs
index ea5813d..96e20be 100644
--- a/nix-js/src/codegen.rs
+++ b/nix-js/src/codegen.rs
@@ -39,6 +39,8 @@ impl<Ctx: CodegenContext> Compile<Ctx> for Ir {
         match self {
             Ir::Int(int) => format!("{int}n"), // Generate BigInt literal
             Ir::Float(float) => float.to_string(),
+            Ir::Bool(bool) => bool.to_string(),
+            Ir::Null(_) => "null".to_string(),
             Ir::Str(s) => s.val.escape_quote(),
             Ir::Path(p) => {
                 // Path needs runtime resolution for interpolated paths
@@ -104,8 +106,8 @@ impl<Ctx: CodegenContext> Compile<Ctx> for BinOp {
             Impl => format!("(!Nix.force({}) || Nix.force({}))", lhs, rhs),
             Con => format!("Nix.op.concat({},{})", lhs, rhs),
             Upd => format!("Nix.op.update({},{})", lhs, rhs),
-            PipeL => format!("Nix.force({})({})", rhs, lhs),
-            PipeR => format!("Nix.force({})({})", lhs, rhs),
+            PipeL => format!("Nix.call({}, {})", rhs, lhs),
+            PipeR => format!("Nix.call({}, {})", lhs, rhs),
         }
     }
 }
diff --git a/nix-js/src/context.rs b/nix-js/src/context.rs
index da81875..ae49f1e 100644
--- a/nix-js/src/context.rs
+++ b/nix-js/src/context.rs
@@ -81,7 +81,7 @@ impl Context {
         let ctx = guard.as_ctx();
 
         let code = ctx.compile_code(expr)?;
-        self.runtime.eval(code, CtxPtr::new(&mut self.ctx))
+        self.runtime.eval(format!("Nix.force({code})"), CtxPtr::new(&mut self.ctx))
     }
 
     pub fn compile_code(&mut self, expr: &str) -> Result<String> {
@@ -116,9 +116,6 @@ impl Default for Ctx {
         global.insert(builtins_sym, builtins_expr);
 
         let free_globals = [
-            "true",
-            "false",
-            "null",
             "abort",
             "baseNameOf",
             "break",
@@ -139,6 +136,11 @@ impl Default for Ctx {
             "throw",
             "toString",
         ];
+        let consts = [
+            ("true", Ir::Bool(true)),
+            ("false", Ir::Bool(false)),
+            ("null", Ir::Null(())),
+        ];
 
         for name in free_globals {
             let name_sym = symbols.get_or_intern(name);
@@ -146,6 +148,12 @@ impl Default for Ctx {
             irs.push(Builtin(name_sym).to_ir());
             global.insert(name_sym, id);
         }
+        for (name, value) in consts {
+            let name_sym = symbols.get_or_intern(name);
+            let id = ExprId(irs.len());
+            irs.push(value);
+            global.insert(name_sym, id);
+        }
 
         Self {
             symbols,
@@ -195,7 +203,7 @@ impl Ctx {
         } else {
             ""
         };
-        let code = format!("({}Nix.force({}))", debug_prefix, code);
+        let code = format!("({}{})", debug_prefix, code);
         #[cfg(debug_assertions)]
         eprintln!("[DEBUG] generated code: {}", &code);
         Ok(code)
diff --git a/nix-js/src/fetcher.rs b/nix-js/src/fetcher.rs
index c746308..cc64dfc 100644
--- a/nix-js/src/fetcher.rs
+++ b/nix-js/src/fetcher.rs
@@ -122,7 +122,7 @@ pub fn op_fetch_tarball(
         .map_err(|e| NixError::from(e.to_string()))?;
 
     let temp_dir = tempfile::tempdir().map_err(|e| NixError::from(e.to_string()))?;
-    let extracted_path = archive::extract_archive(&data, &temp_dir.path().to_path_buf())
+    let extracted_path = archive::extract_archive(&data, temp_dir.path())
         .map_err(|e| NixError::from(e.to_string()))?;
 
     let nar_hash =
diff --git a/nix-js/src/fetcher/nar.rs b/nix-js/src/fetcher/nar.rs
index 19009ef..7b2bebb 100644
--- a/nix-js/src/fetcher/nar.rs
+++ b/nix-js/src/fetcher/nar.rs
@@ -98,6 +98,7 @@ fn write_contents<W: Write>(sink: &mut W, contents: &[u8]) -> io::Result<()> {
 }
 
 #[cfg(test)]
+#[allow(clippy::unwrap_used)]
 mod tests {
     use super::*;
     use tempfile::TempDir;
diff --git a/nix-js/src/ir.rs b/nix-js/src/ir.rs
index 9e023cf..1dc9ad4 100644
--- a/nix-js/src/ir.rs
+++ b/nix-js/src/ir.rs
@@ -52,6 +52,8 @@ ir! {
 
     Int(i64),
     Float(f64),
+    Bool(bool),
+    Null(()),
     Str,
     AttrSet,
     List,