More progress on implementing PCRE matching

regex/matching.go

@@ -152,7 +152,6 @@ func pruneIndices(indices []Match) []Match {
 }
 
 func copyThread(to *nfaState, from nfaState) {
-	to.threadSP = from.threadSP
 	to.threadGroups = append([]Group{}, from.threadGroups...)
 }
 
@@ -253,6 +252,35 @@ func (regex Reg) FindAllSubmatch(str string) []Match {
 	return indices
 }
 
+func addStateToList(idx int, list []nfaState, state nfaState) []nfaState {
+	if stateExists(list, state) {
+		return list
+	}
+	if state.isAlternation {
+		copyThread(state.next, state)
+		list = append(list, addStateToList(idx, list, *state.next)...)
+		copyThread(state.splitState, state)
+		list = append(list, addStateToList(idx, list, *state.splitState)...)
+		return list
+	}
+	if state.isKleene {
+		copyThread(state.splitState, state)
+		list = append(list, addStateToList(idx, list, *state.splitState)...)
+		copyThread(state.next, state)
+		list = append(list, addStateToList(idx, list, *state.next)...)
+		return list
+	}
+	if state.groupBegin {
+		state.threadGroups[state.groupNum].StartIdx = idx
+	}
+	if state.groupEnd {
+		state.threadGroups[state.groupNum].StartIdx = idx
+	}
+	copyThread(state.next, state)
+	return append(list, *state.next)
+
+}
+
 // Helper for FindAllMatches. Returns whether it found a match, the
 // first Match it finds, and how far it got into the string ie. where
 // the next search should start from.
@@ -307,7 +335,6 @@ func findAllSubmatchHelper(start *nfaState, str []rune, offset int, numGroups in
 	//		tempIndices[start.groupNum].startIdx = i
 	//}
 
-	start.threadSP = i
 	currentStates = append(currentStates, *start)
 	var foundMatch bool
 	var isEmptyAndNoAssertion bool
@@ -404,23 +431,28 @@ func findAllSubmatchHelper(start *nfaState, str []rune, offset int, numGroups in
 			}
 
 			if isEmptyAndNoAssertion || foundMatch {
-				allMatches := make([]nfaState, 0)
-				allMatches = append(allMatches, *(currentState.next))
-				slices.Reverse(allMatches)
-				for i := range allMatches {
-					copyThread(&allMatches[i], currentState)
-					if foundMatch && currentState.assert == noneAssert {
-						allMatches[i].threadSP += 1
-					}
-				}
+				nextMatch := *(currentState.next)
+				copyThread(&nextMatch, currentState)
 				if currentState.groupBegin {
-					currentStates = slices.Insert(currentStates, currentStateIdx+1, allMatches...)
+					//	if !stateExists(currentStates, nextMatch) {
+					currentStates = slices.Insert(currentStates, currentStateIdx+1, nextMatch)
+					//}
 				} else if currentState.groupEnd {
-					currentStates = append(currentStates, allMatches...)
+					if !stateExists(currentStates, nextMatch) {
+						currentStates = slices.Insert(currentStates, currentStateIdx+1, nextMatch) // append(currentStates, nextMatch)
+					}
 				} else if currentState.assert != noneAssert {
-					currentStates = append(currentStates, allMatches...)
+					if !stateExists(currentStates, nextMatch) {
+						currentStates = append(currentStates, nextMatch)
+					}
+				} else if currentState.isEmpty && !currentState.groupBegin && !currentState.groupEnd {
+					if !stateExists(currentStates, nextMatch) {
+						currentStates = append(currentStates, nextMatch)
+					}
 				} else {
-					nextStates = append(nextStates, allMatches...)
+					if !stateExists(nextStates, nextMatch) {
+						nextStates = append(nextStates, nextMatch)
+					}
 				}
 			}