Module bridge 

Builtin bridge: tree-walker builtins callable from the VM. Builtin bridge: allows the bytecode VM to call tree-walker builtins.

The VM has native implementations for ~103 builtins, but nixpkgs needs ~119+. Instead of reimplementing every builtin in the VM’s value system, this module provides a callback mechanism that delegates to the tree-walker’s builtins for any builtin the VM doesn’t handle natively.

Architecture

Follows the same pattern as set_flake_resolver in vm.rs: a thread-local callback with an RAII guard for cleanup.

sui-eval (BytecodeEvaluator)
  │
  ├─ set_builtin_bridge(callback)  ← installs bridge before VM eval
  │
  └─ VM execution
      │
      └─ CallBuiltin for "getEnv" etc.
          │
          └─ BuiltinRegistry stub → call_builtin_bridge("getEnv", args)
              │
              └─ callback converts VMValue↔Value, calls tree-walker builtin

Structs

BuiltinBridgeGuard

RAII guard that restores the previous builtin bridge on drop.

Functions

call_builtin_bridge

Call the builtin bridge for a named builtin.

set_builtin_bridge

Install a builtin bridge callback for the current thread.

Type Aliases

BuiltinBridgeFn

Callback type for bridging tree-walker builtins into the VM.