Made zeroLengthMatchState() return a pointer; reduced the number of comparisons performd by nfaState.equals

regex/nfa.go

@@ -402,19 +402,20 @@ func newState() nfaState {
 }
 
 // Creates and returns a state that _always_ has a zero-length match.
-func zeroLengthMatchState() nfaState {
+func zeroLengthMatchState() *nfaState {
-	start := newState()
+	start := &nfaState{}
 	start.content = newContents(epsilon)
 	start.isEmpty = true
 	start.assert = alwaysTrueAssert
+	start.output = append([]*nfaState{}, start)
 	return start
 }
 
 func (s nfaState) equals(other nfaState) bool {
-	return slices.Equal(s.content, other.content) &&
+	return s.isEmpty == other.isEmpty &&
-		s.isEmpty == other.isEmpty &&
 		s.isLast == other.isLast &&
 		slices.Equal(s.output, other.output) &&
+		slices.Equal(s.content, other.content) &&
 		s.next == other.next &&
 		s.isKleene == other.isKleene &&
 		s.isQuestion == other.isQuestion &&