Hojun-Cho
48904e5ef3
findall (regex.ha:923-960) over the memio seeker: one fixed stream for the whole string, per-call suffix substring, absolute io.seek(SET) past the scanner readahead after each match. The append-then-mutate m[0] fix-up is verbatim Hare (the appended header shares m's backing); the zero-length-match rune advancement guard (ha:946-952) carries the infinite-loop protection. search's |success|=2 unwrap is the D13 explicit 3-arm match (ww-core #14); nomem propagates. result_freeall (ha:1119-1124) verbatim, frees no-op (#27). Tests port Hare's own findall table (+test.ha:719-731, the three fold-2a-reachable rows) through run_findall_case's checks, plus field rows pinning adjacency, the one-result overlap pick, multibyte zero-length advancement (utf8sz step != 1), idx != bytesize, the tail-match break, and the empty no-match slice. 989's run gets the conventional timeout-180 wrap: a regression of the zero-length guard would otherwise hang the gate (no-op frees, so no quick OOM exit).
734 lines
25 KiB
Plaintext
734 lines
25 KiB
Plaintext
// regex — POSIX extended regular expressions. Port of
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// ref/hare/regex/regex.ha. Fold 1 = the data model; fold 2a = the
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// compile() literal core (lit/any/match + the leading skip); fold 2b
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// tranche A = the thread-machine scaffolding (thread/newmatch types,
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// result_free, strerror); fold 2b tranche B = the engine
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// (delete_thread/is_consuming_inst/add_thread/run_thread); fold 2b
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// tranche C = search, the first end-to-end match; fold 2b tranche D
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// = the exec surface (test/find — the D13 explicit-match spelling of
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// Hare's multi-success `?`, ww-core #14); fold 2c =
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// findall/result_freeall over the memio seeker. Every other
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// metacharacter arm (and replace) is DEFERRED behind compiler fixes —
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// probed pre-port, pA*/pB*/PB*/PC*/PD* probes. They land with those
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// fixes.
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//
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// One fold-1 construct is held back behind a filed compiler/fidelity
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// gap (see the charclass_map site below):
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// - charclass_map (regex.ha:74-87) — a module-level const slice of
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// (str, *fn(rune) bool) tuples. Blocked on the array-literal→slice
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// element-coercion checker gap (#25; type.c:402-404 #258 borrow
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// uses exact type_eq, no element decay).
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package regex;
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import bufio;
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import io;
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import memio;
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import strings;
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import types;
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import encoding.utf8;
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// ref/hare/regex/regex.ha:14 — an error string describing a compilation
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// error.
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export type error = !str;
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// ref/hare/regex/regex.ha:16-30.
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export type inst_lit = rune;
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export type inst_charset = struct { idx: size, is_positive: bool };
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export type inst_any = void;
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export type inst_split = size;
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export type inst_jump = size;
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export type inst_skip = void;
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export type inst_match = bool;
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export type inst_groupstart = size;
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export type inst_groupend = void;
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export type inst_repeat = struct {
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id: size,
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origin: size,
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min: (void | size),
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max: (void | size),
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};
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// ref/hare/regex/regex.ha:32-35.
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export type inst = (inst_lit | inst_any | inst_split | inst_jump |
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inst_skip | inst_match | inst_charset |
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inst_groupstart | inst_groupend |
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inst_repeat);
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// The resulting match of a [[regex]] applied to a string.
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//
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// The first [[capture]] corresponds to the implicit zeroth capture
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// group, i.e. the whole expression.
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//
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// The rest of the [[capture]]s correspond to the rest of the capture
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// groups, i.e. the sub-expressions.
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// ref/hare/regex/regex.ha:44.
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export type result = []capture;
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// A (sub)match corresponding to a regular expression's capture group.
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// ref/hare/regex/regex.ha:47-53.
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export type capture = struct {
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content: str,
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start: size,
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start_bytesize: size,
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end: size,
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end_bytesize: size,
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};
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// ref/hare/regex/regex.ha:55-64.
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type thread = struct {
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pc: size,
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start_idx: size,
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start_bytesize: size,
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root_capture: capture,
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captures: []capture,
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rep_counters: []size,
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matched: bool,
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failed: bool,
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};
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// Discriminates a fresh match from plain void at run_thread's return
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// boundary. ref/hare/regex/regex.ha:66.
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type newmatch = void;
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// ref/hare/regex/regex.ha:68-72.
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export type charset = [](charset_lit_item | charset_range_item |
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charset_class_item);
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export type charset_lit_item = rune;
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export type charset_range_item = (u32, u32);
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export type charset_class_item = (str, *fn(c: rune) bool);
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// ref/hare/regex/regex.ha:74-87 — charclass_map: the const
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// [](str, *fn(rune) bool) table mapping POSIX class tokens to the
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// matching ascii predicate. DEFERRED: the array-literal→slice
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// assignability check (type.c:402-404, the #258 borrow) compares
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// element types with exact type_eq and applies NO element coercion, so
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// the literal `[(":alnum:]", &ascii.isalnum), ...]` (typed
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// `[N](untyped_str, *fn(rune) bool)`) is rejected against the declared
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// `[](str, *fn(rune) bool)`. Minimal repro: `let xs: [](size, size) =
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// [(1, 2)];`. Reshaping to a fixed `[12](...)` array would compile but
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// is an unfaithful workaround (CLAUDE.md rule-7), so the table — and
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// the `import ascii;` it needs — land with the consuming fold (compile)
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// once the checker gap is fixed.
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// ref/hare/regex/regex.ha:89-93.
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export type regex = struct {
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insts: []inst,
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charsets: []charset,
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n_reps: size,
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};
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// Frees resources associated with a [[regex]].
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//
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// ref/hare/regex/regex.ha:96-102, verbatim. The free() builtin is a
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// documented no-op (#27 landed): ww is a no-free runtime (rt/alloc.s:30
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// — the bump allocator can't reclaim, process-exit does), so each free
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// below evaluates its operand and reclaims nothing. Kept verbatim for
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// API + source parity with the Hare surface.
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export fn finish(re: *regex) void = {
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free(re.insts);
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for (let charset .. re.charsets) {
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free(charset);
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};
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free(re.charsets);
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};
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// Compiles a regular expression string into a [[regex]].
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//
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// ref/hare/regex/regex.ha:227-263. Fold 2a ports the literal core:
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// inst_lit / inst_any / inst_match plus the leading inst_skip
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// (regex.ha:261-263 — unanchored exec depends on it). Every other
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// metacharacter arm is one loud not-yet-ported error — the explicit
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// fold boundary; falling to literal would be a silent semantic lie.
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// State serving only the deferred arms is dropped with them:
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// jump_idxs (ha:241-248), the bracket quad (ha:249-252),
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// was_prev_rune_pipe / group_level / capture_idx (ha:253-256).
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//
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// Hare's `defer if (!ok) free(...)` cleanup (ha:231-237) is omitted:
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// ww has no `defer if` (cf lib/strings/strings.ww:85), and the free()
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// builtin is a no-op anyway (#27 — ww is a no-free runtime), so the
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// cleanup would reclaim nothing.
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export fn compile(expr: str) (regex | error | nomem) = {
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// Hare `let insts: []inst = [];` — a bare ww slice declaration
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// zeroes the header (cgen.c:9836 no-rhs multi-word composite
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// zero-fill, symmetric in cgenstmt.ww).
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let insts: []inst;
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let charsets: []charset; // stays empty until the '[' fold
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let iter: strings.iterator = strings.iter(expr);
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let r_idx: size = 0;
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let n_reps: size = 0;
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for (true) {
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let next: (rune | utf8.done) = strings.next(&iter);
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if (r_idx == 0 && next is rune && (next as rune) != '^') {
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// Bare append: ww append returns void; Hare's
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// `append(...)?` nomem propagation is filed #36.
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// Hare appends the bare type name (`inst_skip`) as
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// the void-variant value; in ww that resolves as a
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// symbol ref (cf the alloc(T) rule), so void
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// variants go through a typed let.
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let sk: inst_skip;
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let v: inst = sk;
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append(insts, v);
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};
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// regex.ha:277-284 minus the group_level check (it rides
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// the deferred '(' arm's state).
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let r: rune = match (next) {
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case utf8.done => break;
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case let x: rune => yield x;
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};
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switch (r) {
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case '.': { // regex.ha:460-461
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let av: inst_any;
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let v: inst = av;
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append(insts, v);
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};
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case ']': // regex.ha:315-316 — literal outside a bracket
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append(insts, (r: inst_lit));
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case '\\', '^', '$', '[', '(', ')', '|', '{', '?', '*', '+':
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// fold-2a boundary: regex.ha:286-459 arms deferred.
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return "regex: metacharacter not yet ported": error;
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case: // regex.ha:462-463
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append(insts, (r: inst_lit));
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};
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r_idx += 1;
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};
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// regex.ha:475-477. `$` appends true: inst_match — deferred, so
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// the guard can only see no-match today; kept verbatim.
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if (insts.len == 0 || !(insts[insts.len - 1] is inst_match)) {
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append(insts, (false: inst_match));
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};
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// regex.ha:479-484. The alternation fixup (ha:470-473) drops with
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// jump_idxs.
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return regex {
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insts = insts,
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charsets = charsets,
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n_reps = n_reps,
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};
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};
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// ref/hare/regex/regex.ha:547-551, verbatim — both free()s are the
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// documented no-op (#27; see finish()), kept for source parity. ww
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// has no pointer auto-deref, so Hare's `threads[i]` spells
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// `(*threads)[i]` (the test-804-pinned delete shape).
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fn delete_thread(i: size, threads: *[]thread) void = {
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free((*threads)[i].captures);
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free((*threads)[i].rep_counters);
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delete((*threads)[i]);
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};
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// ref/hare/regex/regex.ha:553-555. Hare's multi-type membership test
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// `a is (inst_lit | inst_any | inst_charset)` is loud-rejected by
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// design (filed as a Hare-parity task, ww-core #13); the ruled
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// spelling is the chained ||.
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fn is_consuming_inst(a: inst) bool = {
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return a is inst_lit || a is inst_any || a is inst_charset;
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};
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// ref/hare/regex/regex.ha:557-587. The dedup scan (ha:560-566) is an
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// index loop: ww has no by-ref `&..` range and a by-value range over
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// `*threads` miscompiles (F1, ww-core #11). Hare's `append(...)?`
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// nomem propagation and the ok/defer-if unwind (ha:568/573/586) drop
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// together: ww append returns void (#36 filed) and free() reclaims
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// nothing (#27), so there is nothing to propagate or unwind.
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fn add_thread(threads: *[]thread, parent_idx: size, new_pc: size) (void | nomem) = {
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// Do not add this thread if there is already another thread with
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// the same PC
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for (let k: size = 0; k < (len(*threads): size); k += 1) {
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if ((*threads)[k].pc == new_pc
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&& !(*threads)[k].matched
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&& (*threads)[k].start_idx
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< (*threads)[parent_idx].start_idx) {
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return;
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};
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};
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// Hare dups the parent's captures/rep_counters here
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// (`alloc(threads[parent_idx].captures...)?`, ha:569/572). Every
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// ww route into that dup is blocked today (re-probed post-C3,
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// PB7): the deref-spine spread SOURCE is loud-rejected (#35),
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// the per-element append is loud-rejected (#34 struct element
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// source), and the whole-element let-copy drops bytes (#7/F5).
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// The abort is sound, not a semantic hole: fold-2a's compile()
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// cannot emit inst_groupstart/inst_repeat, so both slices are
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// provably empty in every program this fold can run; the empty
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// case appends honest zeroed headers below. The verbatim dup
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// lands with the group/repeat fold (ww-core #3).
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if ((*threads)[parent_idx].captures.len != 0
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|| (*threads)[parent_idx].rep_counters.len != 0) {
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abort("regex: capture dup not yet portable (#35/#34/#7)");
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};
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let captures: []capture;
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let rep_counters: []size;
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append(*threads, thread {
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pc = new_pc,
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start_idx = (*threads)[parent_idx].start_idx,
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start_bytesize = (*threads)[parent_idx].start_bytesize,
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matched = (*threads)[parent_idx].matched,
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failed = (*threads)[parent_idx].failed,
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captures = captures,
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rep_counters = rep_counters,
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...
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});
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return;
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};
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// ref/hare/regex/regex.ha:589-742. Only the arms fold-2a's compile()
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// can emit execute (skip + match non-consuming; lit + any consuming);
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// every other inst arm is one loud not-yet-ported abort — the fold
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// boundary, the compile() metachar discipline. The "unreachable"
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// aborts on lit/any inside the non-consuming loop (ha:604-605) and
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// the trailing default (ha:738) are Hare's own unreachable arms;
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// Hare spells them bare `abort()`, ww carries a message — the
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// zero-arg builtin form is shadowed in any combined unit that
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// declares its own abort fn (os.ww:16 is private yet shadows
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// cross-module; filed, ww-core #45). Hare's loop match omits inst_charset
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// (consuming — the loop condition excludes it); ww has no
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// match-exhaustiveness analysis, so the omission becomes the loud
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// default arm.
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fn run_thread(
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i: size,
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re: *regex,
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string: str,
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threads: *[]thread,
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r_or_end: (rune | io.eof),
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str_idx: size,
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str_bytesize: size,
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) (void | newmatch | nomem) = {
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let str_bytes: []u8 = strings.toutf8(string);
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if ((*threads)[i].matched) {
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return;
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};
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for (!is_consuming_inst(re.insts[(*threads)[i].pc])) {
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match (re.insts[(*threads)[i].pc]) {
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case inst_lit => abort("regex: unreachable");
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case inst_any => abort("regex: unreachable");
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case inst_split =>
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abort("regex: inst_split not yet ported");
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case inst_jump =>
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abort("regex: inst_jump not yet ported");
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case inst_skip => {
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let new_pc: size = (*threads)[i].pc + 1;
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(*threads)[i].start_idx = str_idx;
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(*threads)[i].start_bytesize = str_bytesize;
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add_thread(threads, i, new_pc)?;
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break;
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};
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case let anchored: inst_match => {
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// Do not match if we need an end-anchored match, but we
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// have not exhausted our string
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//
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// Hare spells `anchored` bare (ha:621) — alias
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// transparency; ww named aliases are nominal in bool /
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// comparison position, so this cast and the consuming
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// arm's (lit: rune) are checker-required.
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if ((anchored: bool) && !(r_or_end is io.eof)) {
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(*threads)[i].failed = true;
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return;
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};
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let content: str = strings.frombytes(str_bytes[
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(*threads)[i].start_bytesize:str_bytesize]);
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(*threads)[i].root_capture = capture {
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start = (*threads)[i].start_idx,
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start_bytesize = (*threads)[i].start_bytesize,
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end = str_idx,
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end_bytesize = str_bytesize,
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content = content,
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};
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(*threads)[i].matched = true;
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let nm: newmatch;
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return nm;
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};
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case inst_groupstart =>
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abort("regex: inst_groupstart not yet ported");
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case inst_groupend =>
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abort("regex: inst_groupend not yet ported");
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case inst_repeat =>
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abort("regex: inst_repeat not yet ported");
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case => abort("regex: unreachable");
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};
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};
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// From now on, we're only matching consuming instructions, and these
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// can't do anything without another rune.
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if (r_or_end is io.eof) {
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(*threads)[i].failed = true;
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return;
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};
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let r: rune = r_or_end as rune;
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match (re.insts[(*threads)[i].pc]) {
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case inst_skip => return;
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case let lit: inst_lit => {
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if (r != (lit: rune)) {
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(*threads)[i].failed = true;
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};
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};
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case inst_any => void;
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case inst_charset =>
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abort("regex: inst_charset not yet ported");
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case => abort("regex: unreachable"); // unreachable (ha:738)
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};
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(*threads)[i].pc += 1;
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return;
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};
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|
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// Attempts to match a regular expression against a string and returns
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// either the longest leftmost match or all matches.
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//
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// ref/hare/regex/regex.ha:746-898. Hare's io::handle param is ww's
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// io.stream (callers pass &strm.vt over a memio.fixed). The
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// (void | []capture | nomem) signature keeps nomem for Hare API
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// parity even though nothing in this fold can produce it: ww append
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// returns void (#36 filed) and scanrune has no nomem member.
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fn search(
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re: *regex,
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string: str,
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h: io.stream,
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need_captures: bool,
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) (void | []capture | nomem) = {
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// Hare builds the initial thread list with `alloc([thread {
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// captures = [], ... }])?` (ha:752-754); ww has per-value alloc
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// only, so the list is a bare decl plus one appended
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|
// fully-defaulted thread (the `...` fill zeroes captures too).
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let threads: []thread;
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append(threads, thread { ... });
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// Hare's defer-block cleanup (ha:755-761) is omitted: ww defer
|
|
// takes a single expression (cf compile()'s omitted `defer if`)
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|
// and every free in the block is the documented no-op (#27).
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|
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// ha:763-765 prefills threads[0].rep_counters via
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// `alloc([0...], re.n_reps)?`. No program this fold can compile
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// has n_reps > 0 (the inst_repeat arm is loud), and the sized
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// fill form has no ww spelling yet — loud, like the inst_repeat
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// arm; the real prefill lands with the repeat fold.
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if (re.n_reps > 0) {
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abort("regex: repetitions not yet ported");
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};
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|
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let str_idx: size = 0;
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// Hare writes `= void` (ha:768); a ww bare tagged decl zeroes
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// the tag, which IS the void member here (PC4-pinned).
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let first_match_idx: (void | size);
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let str_bytesize: size = 0;
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let last_bytesize: size = 0;
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|
|
// ww has no default arguments: Hare's newscanner(handle) maxread
|
|
// default spells types.I32_MAX explicitly (lib/bufio/bufio.ww).
|
|
let scan: bufio.scanner = bufio.newscanner(h, types.I32_MAX);
|
|
defer bufio.finish(&scan);
|
|
for (true) {
|
|
str_bytesize += last_bytesize;
|
|
|
|
if (len(threads) == 0) {
|
|
return;
|
|
};
|
|
|
|
let all_matched: bool = true;
|
|
for (let i: size = 0; i < (len(threads): size); i += 1) {
|
|
if (!threads[i].matched) {
|
|
all_matched = false;
|
|
break;
|
|
};
|
|
};
|
|
|
|
if (all_matched) {
|
|
let best_len: size = 0;
|
|
let best_n_captures: size = 0;
|
|
let best_idx: size = 0;
|
|
for (let i: size = 0; i < (len(threads): size); i += 1) {
|
|
let match_len: size =
|
|
threads[i].root_capture.end
|
|
- threads[i].root_capture.start;
|
|
let is_better: bool = match_len > best_len
|
|
|| match_len == best_len
|
|
&& (len(threads[i].captures): size)
|
|
> best_n_captures;
|
|
if (is_better) {
|
|
best_len = match_len;
|
|
best_idx = i;
|
|
best_n_captures =
|
|
(len(threads[i].captures): size);
|
|
};
|
|
};
|
|
|
|
// length = number of captures (index of final group +
|
|
// 1) + root capture
|
|
let length: size = 1;
|
|
for (let i: size = (len(re.insts): size); i > 0; i -= 1) {
|
|
// match-on-indexed scrutinee binds through a
|
|
// typed let (the run_thread spelling).
|
|
let cur: inst = re.insts[i - 1];
|
|
match (cur) {
|
|
case let z: inst_groupstart => {
|
|
length = (z: size) + 2;
|
|
break;
|
|
};
|
|
case => void;
|
|
};
|
|
};
|
|
// Hare types this `result` with a capacity hint
|
|
// (ha:818). A named-alias local trips the #20/#38
|
|
// alias-value family, so the internal spelling is the
|
|
// structural twin []capture (reverts with ww-core
|
|
// #47); the capacity hint drops with per-value alloc.
|
|
let res: []capture;
|
|
append(res, threads[best_idx].root_capture);
|
|
// ha:820 spreads threads[best_idx].captures into res.
|
|
// The indexed spread source is #35-blocked, but
|
|
// captures only populate via the loud-aborted
|
|
// groupstart arm or add_thread's loud-bounded dup —
|
|
// provably empty in every program this fold can run.
|
|
// Loud-bound like add_thread's dup; the verbatim
|
|
// spread lands with the group fold.
|
|
if (threads[best_idx].captures.len != 0) {
|
|
abort("regex: capture copy not yet ported (#35)");
|
|
};
|
|
// ha:821-824's sized fill-append `[capture { ... }...]`
|
|
// has no ww spelling; the count loop is shape-correct
|
|
// and self-activates with the group fold (length stays
|
|
// 1 until then).
|
|
for (length != (len(res): size)) {
|
|
append(res, capture { ... });
|
|
};
|
|
return res;
|
|
};
|
|
|
|
// ww scanrune has no nomem member, so Hare's `case nomem =>
|
|
// return nomem;` (ha:831-832) drops; the multi-type arms
|
|
// (ha:829/833) split per member (the #13 membership-test
|
|
// gap); the aborts carry messages (the #45 builtin-shadow
|
|
// dodge, cf run_thread). Statement match assigning into the
|
|
// declared local, not Hare's expression match: the cstage
|
|
// checker types a match-expr by its first arm's yield and
|
|
// rejects the io.eof arm against rune — wwstage accepts the
|
|
// expression form, a cs≠ww divergence (filed, ww-core #51;
|
|
// repro scratch/r51.ww).
|
|
let r_or_end: (rune | io.eof);
|
|
match (bufio.scanrune(&scan)) {
|
|
case let r: rune => { r_or_end = r; };
|
|
case io.eof => {
|
|
let e: io.eof;
|
|
r_or_end = e;
|
|
};
|
|
case let e: io.error => abort("regex: scanrune io error");
|
|
case utf8.invalid => abort("regex: scanrune invalid utf8");
|
|
};
|
|
if (r_or_end is rune) {
|
|
last_bytesize = (utf8.runesz(r_or_end as rune): size);
|
|
};
|
|
|
|
for (let i: size = 0; i < (len(threads): size); i += 1) {
|
|
// Hare itself binds run_thread without `?` (ha:841) —
|
|
// its nomem drops on the floor here too.
|
|
let res: (void | newmatch | nomem) = run_thread(i, re,
|
|
string, &threads, r_or_end, str_idx,
|
|
str_bytesize);
|
|
let matchlen: size = threads[i].root_capture.end
|
|
- threads[i].root_capture.start;
|
|
if (res is newmatch && matchlen > 0 && !need_captures) {
|
|
// `return [];` (ha:845) — the empty-slice
|
|
// literal in return position has no ww spelling
|
|
// (#25/#31 ruling); a zero header is a valid
|
|
// empty result.
|
|
let none: []capture;
|
|
return none;
|
|
};
|
|
let is_better: bool = res is newmatch && matchlen > 0
|
|
&& (first_match_idx is void
|
|
|| threads[i].start_idx
|
|
< first_match_idx as size);
|
|
if (is_better) {
|
|
first_match_idx = threads[i].start_idx;
|
|
};
|
|
};
|
|
str_idx += 1;
|
|
|
|
// When we only want the leftmost match, delete all threads
|
|
// that start after the earliest non-zero-length matched
|
|
// thread. (ww has no by-ref `&..` range — index loop, the
|
|
// add_thread divergence.)
|
|
if (first_match_idx is size) {
|
|
for (let k: size = 0; k < (len(threads): size); k += 1) {
|
|
if (threads[k].start_idx
|
|
> first_match_idx as size) {
|
|
threads[k].failed = true;
|
|
};
|
|
};
|
|
};
|
|
|
|
// Delete threads that have a PC that has already been
|
|
// encountered in previous threads. Prioritise threads that
|
|
// have an earlier start_idx, and threads that were added
|
|
// earlier. Hare names these counters i/j (ha:872); they are
|
|
// di/dj here because the wwstage checker resolves the inner
|
|
// init's `i + 1` against a dead same-name `let i: size`
|
|
// sibling scope and rejects size → i64 (cs≠ww, filed
|
|
// ww-core #52).
|
|
for (let di: i64 = 0; di < (len(threads): i64) - 1; di += 1) {
|
|
for (let dj: i64 = di + 1; dj < (len(threads): i64); dj += 1) {
|
|
let same_pc: bool =
|
|
threads[di].pc == threads[dj].pc;
|
|
let none_matched: bool = !threads[dj].matched
|
|
&& !threads[di].matched;
|
|
if (same_pc && none_matched) {
|
|
if (threads[di].start_idx
|
|
<= threads[dj].start_idx) {
|
|
delete_thread((dj: size), &threads);
|
|
dj -= 1;
|
|
} else {
|
|
delete_thread((di: size), &threads);
|
|
di -= 1;
|
|
break;
|
|
};
|
|
};
|
|
};
|
|
};
|
|
|
|
for (let i: size = 0; i < (len(threads): size); i += 1) {
|
|
if (threads[i].failed) {
|
|
delete_thread(i, &threads);
|
|
i -= 1;
|
|
};
|
|
};
|
|
};
|
|
};
|
|
|
|
// Returns whether or not a [[regex]] matches any part of a given
|
|
// string.
|
|
//
|
|
// ref/hare/regex/regex.ha:900-904. Hare's io::handle arg `&strm` is
|
|
// the landed memio→io cast `&strm.vt`. Hare unwraps with
|
|
// `search(...)? is []capture` — a |success|=2 union; ww's `?` is
|
|
// gated to single-success unions (the C6 interim, ww-core #14), so
|
|
// the propagation is spelled as the explicit match harec lowers `?`
|
|
// into (ref/harec/src/check.c:2780) — the ratified D13 spelling,
|
|
// reverts with #14.
|
|
export fn test(re: *regex, string: str) (bool | nomem) = {
|
|
let strm: memio.stream = memio.fixed(strings.toutf8(string));
|
|
let r: (void | []capture | nomem) =
|
|
search(re, string, &strm.vt, false);
|
|
match (r) {
|
|
case let m: []capture => return true;
|
|
case void => return false;
|
|
case let n: nomem => return n;
|
|
};
|
|
};
|
|
|
|
// Attempts to match a [[regex]] against a string and returns the
|
|
// longest leftmost match as a [[result]]. The caller must free the
|
|
// return value with [[result_free]].
|
|
//
|
|
// ref/hare/regex/regex.ha:907-918. Same explicit `?` lowering as
|
|
// test() (D13, ww-core #14); the no-match `return [];` (ha:916)
|
|
// binds a zero header first (#25/#31 ruling) — a valid empty result
|
|
// the caller still result_frees.
|
|
export fn find(re: *regex, string: str) (result | nomem) = {
|
|
let strm: memio.stream = memio.fixed(strings.toutf8(string));
|
|
let r: (void | []capture | nomem) =
|
|
search(re, string, &strm.vt, true);
|
|
match (r) {
|
|
case let m: []capture => return m;
|
|
case void => {
|
|
let empty: []capture;
|
|
return empty;
|
|
};
|
|
case let n: nomem => return n;
|
|
};
|
|
};
|
|
|
|
// Attempts to match a [[regex]] against a string and returns all
|
|
// non-overlapping matches as a slice of [[result]]s. The caller must
|
|
// free the return value with [[result_freeall]].
|
|
//
|
|
// ref/hare/regex/regex.ha:920-960. Hare's ok-flag + `defer if (!ok)
|
|
// result_freeall(res)` (ha:924-926) is omitted: the flag's only use
|
|
// is the defer-if, ww defer takes a single expression, and the frees
|
|
// are the documented no-op (#27) — compile()'s omitted `defer if`
|
|
// precedent. The `search(...)?` unwrap (ha:933) is the same explicit
|
|
// D13 lowering as test()/find() (ww-core #14); the nomem arm
|
|
// propagates verbatim.
|
|
export fn findall(re: *regex, string: str) ([]result | nomem) = {
|
|
let res: []result;
|
|
let str_idx: size = 0;
|
|
let str_bytesize: size = 0;
|
|
let strm: memio.stream = memio.fixed(strings.toutf8(string));
|
|
let str_bytes: []u8 = strings.toutf8(string);
|
|
for (true) {
|
|
let substring: str =
|
|
strings.frombytes(str_bytes[str_bytesize:]);
|
|
let r: (void | []capture | nomem) =
|
|
search(re, substring, &strm.vt, true);
|
|
match (r) {
|
|
case let m: []capture => {
|
|
// Hare appends m and THEN fixes m[0] up from
|
|
// substring- to whole-string-relative (ha:935-939):
|
|
// the appended header shares m's backing, so the
|
|
// mutations below are visible through res. Kept
|
|
// verbatim — the aliasing is the subtle bit.
|
|
append(res, m);
|
|
m[0].start += str_idx;
|
|
m[0].end += str_idx;
|
|
m[0].start_bytesize += str_bytesize;
|
|
m[0].end_bytesize += str_bytesize;
|
|
str_idx = m[0].end;
|
|
str_bytesize = m[0].end_bytesize;
|
|
if (m[0].start_bytesize == (len(str_bytes): size)) {
|
|
// end-of-string reached
|
|
break;
|
|
};
|
|
if (m[0].start_bytesize == m[0].end_bytesize) {
|
|
// zero-length match: forward rune and byte
|
|
// indices (ha:946-952 — the guard against
|
|
// the classic findall infinite loop)
|
|
str_idx += 1;
|
|
str_bytesize += (utf8.utf8sz(
|
|
str_bytes[str_bytesize])!: size);
|
|
};
|
|
// ha:953-954: each search call's scanner buffers
|
|
// past what scanrune consumed; the absolute SET
|
|
// repositions the underlying stream before the
|
|
// next call builds a fresh scanner.
|
|
io.seek(&strm.vt, (str_bytesize: io.off),
|
|
io.whence.SET)!;
|
|
};
|
|
case void => break;
|
|
case let n: nomem => return n;
|
|
};
|
|
};
|
|
return res;
|
|
};
|
|
|
|
// Frees a [[result]].
|
|
//
|
|
// ref/hare/regex/regex.ha:1113-1116, verbatim — the free() builtin is
|
|
// the documented no-op (#27; see finish()).
|
|
export fn result_free(s: result) void = {
|
|
free(s);
|
|
};
|
|
|
|
// Frees a slice of [[result]]s.
|
|
//
|
|
// ref/hare/regex/regex.ha:1119-1124, verbatim — both frees are the
|
|
// documented no-op (#27).
|
|
export fn result_freeall(s: []result) void = {
|
|
for (let r .. s) {
|
|
result_free(r);
|
|
};
|
|
free(s);
|
|
};
|
|
|
|
// Converts an [[error]] into a user-friendly string.
|
|
//
|
|
// ref/hare/regex/regex.ha:1126-1127 (expression-bodied in Hare; ww
|
|
// fns take block bodies).
|
|
export fn strerror(err: error) str = {
|
|
return err;
|
|
};
|