Fixed kleene star behavior, which used to behave like a '+'

nfa.go

@@ -4,10 +4,11 @@ const EPSILON int = 0
 
 type State struct {
 	content     int              // Contents of current state
-	isEmpty     bool             // If it is empty - Union operator states will be empty
+	isEmpty     bool             // If it is empty - Union operator and Kleene star states will be empty
 	isLast      bool             // If it is the last state (acept state)
 	output      []*State         // The outputs of the current state ie. the 'outward arrows'. A union operator state will have more than one of these.
 	transitions map[int][]*State // Transitions to different states (maps a character (int representation) to a _list of states. This is useful if one character can lead multiple states eg. ab|aa)
+	isKleene    bool             // Identifies whether current node is a 0-state representing Kleene star
 }
 
 type NFA struct {
@@ -25,6 +26,15 @@ func verifyLastStatesHelper(state *State, visited map[*State]bool) {
 		state.isLast = true
 		return
 	}
+
+	if len(state.transitions) == 1 && state.isKleene { // A State representing a Kleene Star has a transition going out, which loops back to it. If that is the only transition (and it contains only one state), then it must be a last-state
+		for _, v := range state.transitions { // Should only loop once
+			if len(v) == 1 {
+				state.isLast = true
+				return
+			}
+		}
+	}
 	if visited[state] == true {
 		return
 	}