6 Commits

Author	SHA1	Message	Date
Yukihiro "Matz" Matsumoto	101f8c69a1	mruby-regexp: implement fixed-length lookbehind assertions ... Add (?<=...) positive and (?<!...) negative lookbehind support. The sub-pattern must have a fixed byte length (no quantifiers or alternation), computed at compile time and stored in the instruction. At execution time, the engine backs up by that many bytes and runs the sub-pattern forward. Maximum lookbehind length is 255 bytes. Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:32 +09:00
Yukihiro "Matz" Matsumoto	78d761addf	mruby-regexp: implement extended mode (x flag) ... The x flag ignores unescaped whitespace and #comments in patterns, making complex regexps more readable. Whitespace inside character classes [...] remains literal. Implemented as a preprocessing step that strips whitespace/comments before compilation. Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:30 +09:00
Yukihiro "Matz" Matsumoto	3c68e49178	mruby-regexp: add lookahead assertions (?=...) and (?!...) ... implement positive and negative lookahead in the backtracking engine: - (?=pattern): succeeds if pattern matches at current position without consuming characters - (?!pattern): succeeds if pattern does NOT match at current position new bytecodes RE_LOOKAHEAD and RE_NEG_LOOKAHEAD implemented in the backtracking engine via nested bt_match calls. Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:29 +09:00
Yukihiro "Matz" Matsumoto	7283560215	mruby-regexp: add named captures (?<name>...) ... support named capture groups in patterns: - compiler parses (?<name>...) syntax and builds name table - MatchData#[:name] and MatchData#["name"] access by name - MatchData#named_captures returns {name => value} hash - Regexp#named_captures returns {name => group_number} hash - named captures stored in mrb_regexp_pattern for GC safety Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:28 +09:00
Yukihiro "Matz" Matsumoto	8d92379d7c	mruby-regexp: fix non-greedy quantifiers (*?, +?, ??) ... non-greedy patterns now correctly match the shortest possible string. patterns with non-greedy quantifiers are dispatched to the backtracking engine which naturally handles non-greedy semantics. the Pike VM continues to be used for purely greedy patterns (O(n*m) guarantee). Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:28 +09:00
Yukihiro "Matz" Matsumoto	1cfa153ff3	mruby-regexp: add built-in regexp engine with Pike VM ... implement a lightweight NFA-based regular expression engine for mruby: engine (src/re_compile.c, src/re_exec.c, src/re_utf8.c): - Pike VM (Thompson NFA simulation) with O(n*m) time guarantee - ReDoS-resistant by design (no backtracking for basic patterns) - supports: literals, ., *, +, ?, {n,m}, [], [^], |, () - character classes: \d, \w, \s and negations - anchors: ^, $, \A, \z, \Z, \b, \B - flags: i (ignorecase), m (multiline/dotall) - captures with MatchData Ruby API (src/regexp.c, mrblib/string_regexp.rb): - Regexp.new, #match, #match?, #=~, #===, #source, #inspect - Regexp.escape, Regexp::IGNORECASE/MULTILINE constants - MatchData#[], #captures, #to_a, #begin, #end, #pre_match, #post_match - String#match, #match?, #=~, #sub, #gsub, #scan, #split ~1700 lines of C + ~120 lines of Ruby. no external dependencies. Co-authored-by: Claude <noreply@anthropic.com>	2026-04-23 19:25:27 +09:00