Added function for concatenation and kleene star

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
+}