diff options
Diffstat (limited to 'src/pkg/regexp/regexp.go')
| -rw-r--r-- | src/pkg/regexp/regexp.go | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/src/pkg/regexp/regexp.go b/src/pkg/regexp/regexp.go index edf91531d..4dd430ea6 100644 --- a/src/pkg/regexp/regexp.go +++ b/src/pkg/regexp/regexp.go @@ -727,34 +727,35 @@ func (a *matchArena) noMatch() *matchVec { } type state struct { - inst instr // next instruction to execute - match *matchVec + inst instr // next instruction to execute + prefixed bool // this match began with a fixed prefix + match *matchVec } // Append new state to to-do list. Leftmost-longest wins so avoid // adding a state that's already active. The matchVec will be inc-ref'ed // if it is assigned to a state. -func (a *matchArena) addState(s []state, inst instr, match *matchVec, pos, end int) []state { +func (a *matchArena) addState(s []state, inst instr, prefixed bool, match *matchVec, pos, end int) []state { switch inst.kind() { case _BOT: if pos == 0 { - s = a.addState(s, inst.next(), match, pos, end) + s = a.addState(s, inst.next(), prefixed, match, pos, end) } return s case _EOT: if pos == end { - s = a.addState(s, inst.next(), match, pos, end) + s = a.addState(s, inst.next(), prefixed, match, pos, end) } return s case _BRA: n := inst.(*_Bra).n match.m[2*n] = pos - s = a.addState(s, inst.next(), match, pos, end) + s = a.addState(s, inst.next(), prefixed, match, pos, end) return s case _EBRA: n := inst.(*_Ebra).n match.m[2*n+1] = pos - s = a.addState(s, inst.next(), match, pos, end) + s = a.addState(s, inst.next(), prefixed, match, pos, end) return s } index := inst.index() @@ -773,12 +774,13 @@ func (a *matchArena) addState(s []state, inst instr, match *matchVec, pos, end i } s = s[0 : l+1] s[l].inst = inst + s[l].prefixed = prefixed s[l].match = match match.ref++ if inst.kind() == _ALT { - s = a.addState(s, inst.(*_Alt).left, a.copy(match), pos, end) + s = a.addState(s, inst.(*_Alt).left, prefixed, a.copy(match), pos, end) // give other branch a copy of this match vector - s = a.addState(s, inst.next(), a.copy(match), pos, end) + s = a.addState(s, inst.next(), prefixed, a.copy(match), pos, end) } return s } @@ -818,10 +820,10 @@ func (re *Regexp) doExecute(str string, bytestr []byte, pos int) []int { match := arena.noMatch() match.m[0] = pos if prefixed { - s[out] = arena.addState(s[out], re.prefixStart, match, pos, end) + s[out] = arena.addState(s[out], re.prefixStart, true, match, pos, end) prefixed = false // next iteration should start at beginning of machine. } else { - s[out] = arena.addState(s[out], re.start.next(), match, pos, end) + s[out] = arena.addState(s[out], re.start.next(), false, match, pos, end) } arena.free(match) // if addState saved it, ref was incremented } @@ -852,19 +854,19 @@ func (re *Regexp) doExecute(str string, bytestr []byte, pos int) []int { case _EOT: case _CHAR: if c == st.inst.(*_Char).char { - s[out] = arena.addState(s[out], st.inst.next(), st.match, pos, end) + s[out] = arena.addState(s[out], st.inst.next(), st.prefixed, st.match, pos, end) } case _CHARCLASS: if st.inst.(*_CharClass).matches(c) { - s[out] = arena.addState(s[out], st.inst.next(), st.match, pos, end) + s[out] = arena.addState(s[out], st.inst.next(), st.prefixed, st.match, pos, end) } case _ANY: if c != endOfFile { - s[out] = arena.addState(s[out], st.inst.next(), st.match, pos, end) + s[out] = arena.addState(s[out], st.inst.next(), st.prefixed, st.match, pos, end) } case _NOTNL: if c != endOfFile && c != '\n' { - s[out] = arena.addState(s[out], st.inst.next(), st.match, pos, end) + s[out] = arena.addState(s[out], st.inst.next(), st.prefixed, st.match, pos, end) } case _BRA: case _EBRA: @@ -892,7 +894,7 @@ func (re *Regexp) doExecute(str string, bytestr []byte, pos int) []int { return nil } // if match found, back up start of match by width of prefix. - if re.prefix != "" && len(final.match.m) > 0 { + if final.prefixed && len(final.match.m) > 0 { final.match.m[0] -= len(re.prefix) } return final.match.m |