From b327143fa2660a7ac572d0d5a4972aaaa756c6c5 Mon Sep 17 00:00:00 2001
From: Aadhavan Srinivasan <aadhavan@twomorecents.org>
Date: Sun, 27 Oct 2024 11:19:06 -0400
Subject: [PATCH] Added function for concatenation and kleene star

---
 nfa.go | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/nfa.go b/nfa.go
index cc1a9c2..05c40c0 100644
--- a/nfa.go
+++ b/nfa.go
@@ -48,7 +48,29 @@ func verifyLastStatesHelper(state *State, visited map[*State]bool) {
 	}
 }
 
-// verifyLastStates penables the 'isLast' flag for the leaf nodes (last states)
+// verifyLastStates enables the 'isLast' flag for the leaf nodes (last states)
 func verifyLastStates(start []*State) {
 	verifyLastStatesHelper(start[0], make(map[*State]bool))
 }
+
+func concatenate(s1 *State, s2 *State) *State {
+	for i := range s1.output {
+		s1.output[i].transitions[s2.content] = append(s1.output[i].transitions[s2.content], s2)
+	}
+	s1.output = s2.output
+	return s1
+}
+
+func kleene(s1 State) *State {
+	toReturn := &State{}
+	toReturn.transitions = make(map[int][]*State)
+	toReturn.content = EPSILON
+	toReturn.isEmpty = true
+	toReturn.isKleene = true
+	toReturn.output = append(toReturn.output, toReturn)
+	for i := range s1.output {
+		s1.output[i].transitions[toReturn.content] = append(s1.output[i].transitions[toReturn.content], toReturn)
+	}
+	toReturn.transitions[s1.content] = append(toReturn.transitions[s1.content], &s1)
+	return toReturn
+}