The type system now keeps its nullability promise: a `?T` value cannot be
used, stored, or dereferenced as a plain `T` without narrowing. The canonical
evidence probe (return b.v where v: ?Int, fn -> Int) that compiled clean for
months now fails with WO-E211.
- WO-E211 (un-narrowed use): arithmetic and </<=/>/>= operands, and/or
operands (?Bool), interpolation segments, for-iterables, and returns whose
declared type is not nullable.
- WO-E212 (boundary): nil or ?T stored into a non-nullable slot — annotated
let, assignment to a confidently-typed local (cenv, never the placeholder
env — a placeholder target must stay silent) or a resolvable class field.
- WO-E213 (deref): field/index access through a possibly-nil base.
- Narrowing (locals only — a field place can be re-assigned between check
and use, so chains bind to a local first): `if x != nil { }` narrows the
branch; a DIVERGING then-branch (`if x == nil { return }`) narrows after
the if; `x != nil and x.n > 3` narrows and/or right operands
(short-circuit); `while x != nil` narrows the body. The narrow is
un-applied when an else-less then-env leaks out un-diverged (the existing
env-leak convention must not leak the narrow).
- No false positives by construction: env/cenv types are declared or
confidently inferred; the placeholder fallbacks are plain scalars, never
?T. The whole golden suite passed untouched (540/0).
- Samples updated to the bind-then-narrow idiom (log-watcher config decode +
supervisor lock/next_fire, gc-cycle ring print) — 22 genuine unnarrowed-nil
sites; employee needed zero changes. All acceptances green.
- Corpus: compile-fail/{nullable-unnarrowed-use,nullable-nil-into-plain,
nullable-deref-unchecked} + run/nullable-narrowing (all four forms) — 83/0.
- Catalog: E211/E212/E213 move from "Reserved, not yet emitted" to the main
table; nullable-types-implementation.md status flipped to ENFORCED
(historical record kept); plan 8 Task 6 ticked (boxed scalar cells
superseded by WO_NIL_SCALAR); board updated.
Verified: woc-test 540/0 + test_diag 14/0; oop-e2e 83/0; oop-accept ALL MET;
log-watcher 7/0; employee 8/0; gc-cycle ring prints + reclaims.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
docs/examples/log-watcher now COMPILES AND RUNS: `wovm lw.wob watch app.log 2 1`
tails a live file, classifies levels and fires its alert
("last entry is error, quiet for 2s"). corpus 71/0, woc 565/0, wovm gates green.
- program mode: the entry is `fn main` taking nothing or one `multi Text`;
runtime/src/main.c builds that list from the program's own arguments (not
the program name, not the image path) and the entry's return value is the
process exit code (low byte); the loader accepts a 0- or 1-arg free-fn entry
- `+` on Text is now WO-E201 pointing at `..`. This was a memory-safety hole,
not a style nit: the emitter lowered it to ADD on two heap pointers, and the
workload's own `out = out + char_of(c)` produced a wild pointer that
segfaulted the VM inside starts_with. Reported off confident types only
- `x == nil` / `x != nil` lower to EQ (a word compare), never EQS: nil is the
zero word and EQS dereferences its operands, so a nil guard would trap
instead of answering
- docs/examples/log-watcher: seven `+`-on-Text sites corrected to `..`
(logtail sanitize, mcp header/body/carry assembly, supervisor detections
line) — the sample was carrying the Haxe habit, and the language reserves
`+` for arithmetic by doctrine
- wovm CLI takes arguments after the image path (`wovm <file.wob> [args...]`)
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
