Three new files forming the bytecode compilation pipeline:
spec/bytecode.sx — opcode definitions (~65 ops):
- Stack/constant ops (CONST, NIL, TRUE, POP, DUP)
- Lexical variable access (LOCAL_GET/SET, UPVALUE_GET/SET, GLOBAL_GET/SET)
- Jump-based control flow (JUMP, JUMP_IF_FALSE/TRUE)
- Function ops (CALL, TAIL_CALL, RETURN, CLOSURE, CALL_PRIM)
- HO form ops (ITER_INIT/NEXT, MAP_OPEN/APPEND/CLOSE)
- Scope/continuation ops (SCOPE_PUSH/POP, RESET, SHIFT)
- Aser specialization (ASER_TAG, ASER_FRAG)
spec/compiler.sx — SX-to-bytecode compiler (SX code, portable):
- Scope analysis: resolve variables to local/upvalue/global at compile time
- Tail position detection for TCO
- Code generation for: if, when, and, or, let, begin, lambda,
define, set!, quote, function calls, primitive calls
- Constant pool with deduplication
- Jump patching for forward references
hosts/ocaml/lib/sx_vm.ml — bytecode interpreter (OCaml):
- Stack-based VM with array-backed operand stack
- Call frames with base pointer for locals
- Direct opcode dispatch via pattern match
- Zero allocation per step (unlike CEK machine's dict-per-step)
- Handles: constants, variables, jumps, calls, primitives,
collections, string concat, define
Architecture: compiler.sx is spec (SX, portable). VM is platform
(OCaml-native). Same bytecode runs on JS/WASM VMs.
Also includes: CekFrame record optimization in transpiler.sx
(29 frame types as records instead of Hashtbl).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
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