Port of ref/hare/fnmatch/fnmatch.ha. Public surface mirrors Hare:
`flag` enum (NONE/PATHNAME/NOESCAPE/PERIOD) and `fnmatch(pattern,
string, flags) bool`.
Algorithm is the three-phase sea-of-stars (also used in musl):
exact-match the prefix before the first `*`, exact-match the tail
after the last `*`, then greedily match each star-delimited middle
segment with backtrack on inner failure. No exponential corner —
each star anchors a "match found" at strictly increasing positions.
Bracket expressions: Hare-strict — `!` for negation, `^` rejected
as invalid; `]` as first member legal, trailing `-` literal, all
12 POSIX classes ([:alnum:] … [:xdigit:]) via direct streq + the
ascii.is* predicates.
Divergences from Hare (documented in fnmatch.ww docblock):
- byte-indexed cursors in place of strings::iterator (no UTF-8
rune iter yet); ASCII-only meaningful, multibyte matches
byte-identically. Graduates "in one go" per lib/CLAUDE.md
when the language stack grows rune iteration.
- invalid pattern collapses to `false` at the public boundary
(Hare's `b is bool && b: bool;`); a try-shaped diagnostic
entry can be added later without churning the surface.
- tail-match uses a forward cursor at `string.len - cnt`
instead of riter/prev — same byte sequence either way.
Test fixture follows the project's helper-per-row table-driven
shape (precedent: lib/encoding/base32/base32_test.ww). 8 @test
fns clustered by feature (basic / brackets / ctype / period /
noescape / musl_basic / pathname / combined), ~95 rows total
adapted from Hare's +test.ha plus musl-derived edge cases.
Wired as 972_fnmatch_run alongside 970_fmt_run / 971_log_run in
the stdlib-runtime band.
Unblocked by 7f60ebb (cstage+wwstage SK_USE→SK_X promotion
missing use_alias), which is what let the module name `fnmatch`
coexist with an exported leaf fn `fnmatch`.
Hojun-Cho
1d5ff201ee