- ast.ml: Added Nullable variant to field_ty; param.ty/method_sig.ret/method_decl.ret now use field_ty
- parser.ml: Parse ? prefix for field types, return types, parameters
- dump.ml: Render ?T in --dump-ast output
- types.ml: New typechecker (Task 6) with nullable field-kind derivation (WO_K_NULLABLE=6)
- dune: Added types module
- Added golden test fixtures for nullable types and statement/expression parser
- Added implementation plan doc
prototypes/wo-rt-c — single-file C reference of the writeonce runtime
layer, zero deps beyond libc + kernel uapi: thread-per-core io_uring
event loops (raw syscalls, no liburing), SO_REUSEPORT listeners, one
mlock'd mmap arena sharded by address, WAL dual-write with group commit
(HTTP ack only after the fsync CQE), boot-time snapshot + WAL replay
recovery, and a bench harness with a Go net/http comparison server.
Measured on 20 cores: 908k reads/s p99 154us and 643k fsync-acked
commits/s p99 177us on 8 shards, vs Go net/http 495k/355k (no
durability) on 20 cores. Crash-under-load testing found and fixed an
ack-before-fsync race and an fd-reuse ABA hazard in commit-ack parking.
docs/plan/exploration/c-runtime — the phased plan (00, exit evidence
per phase), the one-address architecture trace (01), and the
single-binary end-goal contract (02). justfile carries the demo and
bench recipes; .gitignore covers binaries and data dirs.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
