`type Foo = enum [intT] { NAME [= expr], ... };`. Storage defaults
to i32; members auto-increment from 0 (or last+1) when `= expr` is
omitted, and value expressions can reference earlier siblings —
enough surface for io::mode-style flag enums (`RDWR = READ | WRITE`).
`Foo.MEMBER` folds to an N_INTLIT in the checker, typed as the
named enum. Binops on enum values yield the same enum (type_eq on
the named pointer), so `mode.R | mode.W` is a `mode`. Enum ↔ int
is a reinterpret-only `as` cast — same register, no tag wrap — so
`mode.RDWR as i32` and `1 as mode` both work without runtime ops.
`is`/`?`/`!` are still tagged-union-only. CSP runtime (chan/proc)
is unchanged; only the type-system slot is touched here.
`match (e) { ... }` can now sit in expression position, with each
arm using `yield expr;` to produce the match's value:
let v = match (r) {
case let n: i32 => yield n + 1;
case let s: str => yield s.len: i32 + 100;
};
TK_YIELD keyword + N_YIELD AST node, both appended at the tail of
their enums to keep prior numeric values byte-stable for the
wwdump-diff gates.
Checker: cexpr for N_MATCH walks each arm's body looking for the
first N_YIELD; the match's type is the unified yield type (or
ty_void if no yield, preserving the statement-form semantics).
Mismatched arm yields are flagged.
Cgen: a yield-target stack (separate from the loop break stack)
holds each enclosing match's end label. N_YIELD evaluates its
expression into AX (and BX for str) and JMPs to the topmost entry.
cgmatch pushes its end label on entry and pops on exit.
Selfhost mirror: lib/ww/lex/tok.ww kwtab+name, lib/ww/ast.ww
N_YIELD def+print, lib/ww/parse/stmt.ww yield-stmt; selfhost cgen
adds a yieldbuf to the cgen struct and a cgyield helper. Verified
end-to-end: a yield-using program compiled via the wwstage cgen
matches the C-cgen build's exit code.
`type invalid = i32` (payload: byte index of first bad rune; mirrors
Hare's strconv::invalid = !size) and `type overflow = void` (Hare's
overflow = !void). stoi64/stou64 now return these instead of the
str-error placeholder. atoi64 dropped — lib/CLAUDE.md says graduate
in one go, don't keep both shapes around.
To produce the void variant payload, `void` is now a real
expression literal (TK_VOID kw, N_VOIDLIT). It evaluates to ty_void;
codegen emits MOVQ $0, AX. Both kinds are appended at the tail of
their enums to keep prior numeric values byte-stable for the
wwdump-diff fixtures.
check_file reorder: USE declarations are now installed in pass 1
alongside the type-decl placeholders so dotted type references
(`strconv.invalid` from a typedecl body) resolve. DEF/FN/LET silently
overwrite a USE-occupied slot — matches the old behavior where USE
silently no-op'd when a same-name fn/def existed (the conflict
manifested in selfhost main.combined.ww at `use parse;` colliding
with `export fn parse(a)`).
selfhost mirror: lib/ww/lex/tok.ww kwtab+name; lib/ww/ast.ww
N_VOIDLIT def+print; lib/ww/parse/{expr,parse}.ww TK_VOID handling;
selfhost/cmd/wcc/cgenexpr.ww N_VOIDLIT codegen.
`e is T` returns bool (variant tag == T's index); `e as T` unwraps
to T or exit(1) on mismatch. Postfix, same precedence as `:` cast.
TK_IS / N_TYPETEST / N_TYPEASSERT appended at the tail of their
enums so every prior numeric value stays unchanged — the
990_selfhost wwdump-diff stays byte-clean.
Cgen mirrors the match-case slot-based load (tag at +0, value at
+8/+16), so an N_IDENT tagged-union local works just like a
match scrutinee. Selfhost cgen inlines the slot resolution
because the wwstage cgen drops sign bits on `*i32` output
parameters in this position.
Renames `errors.is` -> `errors.equal` (the only naming collision;
the existing comment already noted it shared shape with
strings.equal/bytes.equal).
Plan 9-style w-prefix on the per-arch tools, disambiguating from the
real Plan 9 6c/6a/6l in ref/plan9front/:
cmd/wwc/ → cmd/wcc/ libwwc.a → libwcc.a
cmd/6{c,a,l} → cmd/w6{c,a,l} binary names too
test/wwc/ → test/wcc/ 6 test files w/ w6 prefix
selfhost/cmd mirror in lockstep
bootstrap/amd64/{w6c,w6a,w6l} snapshot binaries (gitignored)
WW_6{C,A,L} → WW_W6{C,A,L} env-var overrides
Plan 9 source-tree refs ("Plan 9 6c shape", ref/plan9front/, etc.)
preserved. Hare-style driver, both C and ww sides:
ww test [path] discover *_test.ww in a directory module, run
each; single-file mode for `ww test foo.ww`
Module-by-name `ww build foo` resolves to foo.ww or foo/foo.ww
via search path (cwd : -I dirs : $WW_LIB)
Default-to-cwd `ww build` / `ww test` build the cwd module
Run pass-through `ww run path arg1 arg2` reaches the program
lib/os: getcwd (79) and getdents64 (217) syscalls power `.` resolution
and directory enumeration on the ww side.
Makefile: wwstage tool deps now include lib/os/os.ww (+ lib/strconv
for wwdump_ww) so lib/* edits force their rebuild instead of leaving
stale binaries — surfaced when test 995 first failed against a stale
w6c_ww built before the lib/os additions.
Test 993 byte-identical parity gate (C-side ww vs ww-side ww_ww on a
build corpus) stays green; all 19 tests pass.
