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Commented out unused functions; use new nfaState parameters

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implementPCREMatchingRules
Aadhavan Srinivasan 1 month ago
parent cca8c7cda2
commit fbc9bea9fb
1 changed files with 68 additions and 77 deletions
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145
regex/matching.go
Unescape Escape View File

@ -74,58 +74,58 @@ func getZeroGroup(m Match) Group {
// given slice. It returns the resulting states. If any of the resulting states is a 0-state,
// the second ret val is true.
// If a state begins or ends a capturing group, its 'thread' is updated to contain the correct index.
func takeZeroState(states []*nfaState, numGroups int, idx int) (rtv []*nfaState, isZero bool) {
for _, state := range states {
if len(state.transitions[epsilon]) > 0 {
for _, s := range state.transitions[epsilon] {
if s.threadGroups == nil {
s.threadGroups = newMatch(numGroups + 1)
}
copy(s.threadGroups, state.threadGroups)
if s.groupBegin {
s.threadGroups[s.groupNum].StartIdx = idx
// openParenGroups = append(openParenGroups, s.groupNum)
}
if s.groupEnd {
s.threadGroups[s.groupNum].EndIdx = idx
// closeParenGroups = append(closeParenGroups, s.groupNum)
}
}
rtv = append(rtv, state.transitions[epsilon]...)
}
}
for _, state := range rtv {
if len(state.transitions[epsilon]) > 0 {
return rtv, true
}
}
return rtv, false
}
//func takeZeroState(states []*nfaState, numGroups int, idx int) (rtv []*nfaState, isZero bool) {
// for _, state := range states {
// if len(state.transitions[epsilon]) > 0 {
// for _, s := range state.transitions[epsilon] {
// if s.threadGroups == nil {
// s.threadGroups = newMatch(numGroups + 1)
// }
// copy(s.threadGroups, state.threadGroups)
// if s.groupBegin {
// s.threadGroups[s.groupNum].StartIdx = idx
// // openParenGroups = append(openParenGroups, s.groupNum)
// }
// if s.groupEnd {
// s.threadGroups[s.groupNum].EndIdx = idx
// // closeParenGroups = append(closeParenGroups, s.groupNum)
// }
// }
// rtv = append(rtv, state.transitions[epsilon]...)
// }
// }
// for _, state := range rtv {
// if len(state.transitions[epsilon]) > 0 {
// return rtv, true
// }
// }
// return rtv, false
//}
// zeroMatchPossible returns true if a zero-length match is possible
// from any of the given states, given the string and our position in it.
// It uses the same algorithm to find zero-states as the one inside the loop,
// so I should probably put it in a function.
func zeroMatchPossible(str []rune, idx int, numGroups int, states ...*nfaState) bool {
zeroStates, isZero := takeZeroState(states, numGroups, idx)
tempstates := make([]*nfaState, 0, len(zeroStates)+len(states))
tempstates = append(tempstates, states...)
tempstates = append(tempstates, zeroStates...)
num_appended := 0 // number of unique states addded to tempstates
for isZero == true {
zeroStates, isZero = takeZeroState(tempstates, numGroups, idx)
tempstates, num_appended = uniqueAppend(tempstates, zeroStates...)
if num_appended == 0 { // break if we haven't appended any more unique values
break
}
}
for _, state := range tempstates {
if state.isEmpty && (state.assert == noneAssert || state.checkAssertion(str, idx)) && state.isLast {
return true
}
}
return false
}
//func zeroMatchPossible(str []rune, idx int, numGroups int, states ...*nfaState) bool {
// zeroStates, isZero := takeZeroState(states, numGroups, idx)
// tempstates := make([]*nfaState, 0, len(zeroStates)+len(states))
// tempstates = append(tempstates, states...)
// tempstates = append(tempstates, zeroStates...)
// num_appended := 0 // number of unique states addded to tempstates
// for isZero == true {
// zeroStates, isZero = takeZeroState(tempstates, numGroups, idx)
// tempstates, num_appended = uniqueAppend(tempstates, zeroStates...)
// if num_appended == 0 { // break if we haven't appended any more unique values
// break
// }
// }
// for _, state := range tempstates {
// if state.isEmpty && (state.assert == noneAssert || state.checkAssertion(str, idx)) && state.isLast {
// return true
// }
// }
// return false
//}
// Prunes the slice by removing overlapping indices.
func pruneIndices(indices []Match) []Match {
@ -376,17 +376,26 @@ func findAllSubmatchHelper(start *nfaState, str []rune, offset int, numGroups in
// Alternation - enqueue left then right state, and continue
if currentState.isAlternation {
leftState := currentState.leftState
copyThread(leftState, currentState)
currentStates = append(currentStates, *currentState.leftState)
rightState := currentState.rightState
copyThread(rightState, currentState)
currentStates = append(currentStates, *currentState.rightState)
if currentState.isKleene { // Reverse order of adding things
rightState := currentState.splitState
copyThread(rightState, currentState)
currentStates = append(currentStates, *currentState.splitState)
leftState := currentState.next
copyThread(leftState, currentState)
currentStates = append(currentStates, *currentState.next)
} else {
leftState := currentState.next
copyThread(leftState, currentState)
currentStates = append(currentStates, *currentState.next)
rightState := currentState.splitState
copyThread(rightState, currentState)
currentStates = append(currentStates, *currentState.splitState)
}
continue
}
// Empty state - enqueue next state, do _not_ increment the SP
if currentState.isEmpty && currentState.assert == noneAssert { //&& currentState.groupBegin == false && currentState.groupEnd == false {
if !currentState.isAlternation && currentState.isEmpty && currentState.assert == noneAssert { //&& currentState.groupBegin == false && currentState.groupEnd == false {
isEmptyAndNoAssertion = true
}
@ -396,12 +405,7 @@ func findAllSubmatchHelper(start *nfaState, str []rune, offset int, numGroups in
if isEmptyAndNoAssertion || foundMatch {
allMatches := make([]nfaState, 0)
for _, v := range currentState.transitions {
dereferenced := funcMap(v, func(s *nfaState) nfaState {
return *s
})
allMatches = append(allMatches, dereferenced...)
}
allMatches = append(allMatches, *(currentState.next))
slices.Reverse(allMatches)
for i := range allMatches {
copyThread(&allMatches[i], currentState)
@ -419,24 +423,11 @@ func findAllSubmatchHelper(start *nfaState, str []rune, offset int, numGroups in
}
if currentState.isLast && len(nextStates) == 0 { // Last state reached
if foundMatch {
if currentState.assert != noneAssert {
currentState.threadGroups[0].EndIdx = idx
} else {
currentState.threadGroups[0].EndIdx = idx + 1
}
if idx == currentState.threadGroups[0].StartIdx {
idx += 1
}
return true, currentState.threadGroups, idx
} else if isEmptyAndNoAssertion {
currentState.threadGroups[0].EndIdx = idx
if idx == currentState.threadGroups[0].StartIdx {
idx++
}
return true, currentState.threadGroups, idx
currentState.threadGroups[0].EndIdx = idx
if idx == currentState.threadGroups[0].StartIdx {
idx += 1
}
return true, currentState.threadGroups, idx
}
}
currentStates = append([]nfaState{}, nextStates...)

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