diff options
Diffstat (limited to 'match.c')
| -rw-r--r-- | match.c | 36 |
1 files changed, 12 insertions, 24 deletions
@@ -602,10 +602,8 @@ static match_t *match(match_ctx_t *ctx, const char *str, pat_t *pat) pat_t rec_op = { .type = BP_LEFTRECURSION, - .start = ref->start, - .end = ref->end, - .min_matchlen = 0, - .max_matchlen = -1, + .start = ref->start, .end = ref->end, + .min_matchlen = 0, .max_matchlen = -1, .args.leftrec = { .match = NULL, .visits = 0, @@ -627,31 +625,21 @@ static match_t *match(match_ctx_t *ctx, const char *str, pat_t *pat) }, }; - const char *prev = str; - match_t *m = match(&ctx2, str, ref); - if (m == NULL) { - cache_failure(ctx, str, pat); - return NULL; - } - - while (rec_op.args.leftrec.visits > 0) { - rec_op.args.leftrec.visits = 0; - if (rec_op.args.leftrec.match && rec_op.args.leftrec.match != m) - recycle_match(&rec_op.args.leftrec.match); + match_t *m = NULL; + // Keep matching as long as left recursion keeps happening and forward progress is made + for (const char *prev = str; m == NULL || (rec_op.args.leftrec.visits > 0 && m->end > prev); prev = m->end) { rec_op.args.leftrec.match = m; - prev = m->end; + rec_op.args.leftrec.visits = 0; match_t *m2 = match(&ctx2, str, ref); - if (m2 == NULL) break; - if (m2->end <= prev) { - recycle_match(&m2); - break; - } - recycle_match(&m); + if (!m2) break; + if (m) recycle_match(&m); m = m2; } - if (rec_op.args.leftrec.match && rec_op.args.leftrec.match != m) - recycle_match(&rec_op.args.leftrec.match); + if (!m) { + cache_failure(ctx, str, pat); + return NULL; + } // This match wrapper mainly exists for record-keeping purposes. // It also helps with visualization of match results. |