Change kleene() to an alternation-style construct

regex/nfa.go

@@ -116,7 +116,6 @@ func cloneStateHelper(stateToClone *nfaState, cloneMap map[*nfaState]*nfaState)
 		clone.rightState = clone
 	}
 	clone.rightState = cloneStateHelper(stateToClone.rightState, cloneMap)
-
 	return clone
 }
 
@@ -326,12 +325,16 @@ func kleene(s1 nfaState) (*nfaState, error) {
 		return nil, fmt.Errorf("previous token is not quantifiable")
 	}
 
-	toReturn := &nfaState{}
-	toReturn.transitions = make(map[int][]*nfaState)
-	toReturn.content = newContents(epsilon)
+	emptyState := zeroLengthMatchState()
+	emptyState.assert = noneAssert
+	toReturn := alternate(&s1, &emptyState)
+
+	//	toReturn := &nfaState{}
+	//	toReturn.transitions = make(map[int][]*nfaState)
+	//	toReturn.content = newContents(epsilon)
 	toReturn.isEmpty = true
 	toReturn.isKleene = true
-	toReturn.output = append(toReturn.output, toReturn)
+	toReturn.output = []*nfaState{&emptyState}
 	for i := range s1.output {
 		for _, c := range toReturn.content {
 			s1.output[i].transitions[c], _ = uniqueAppend(s1.output[i].transitions[c], toReturn)
@@ -340,6 +343,7 @@ func kleene(s1 nfaState) (*nfaState, error) {
 	for _, c := range s1.content {
 		toReturn.transitions[c], _ = uniqueAppend(toReturn.transitions[c], &s1)
 	}
+	//toReturn.kleeneState = &s1
 	return toReturn, nil
 }
 
@@ -374,7 +378,6 @@ func question(s1 *nfaState) *nfaState { // Use the fact that ab? == a(b|)
 	s2.content = newContents(epsilon)
 	s2.output = append(s2.output, s2)
 	s2.isEmpty = true
-	s2.isAlternation = true
 	s3 := alternate(s1, s2)
 	return s3
 }