Created a function to return a state that will always have a zero-length state

nfa.go

@@ -333,3 +333,12 @@ func newState() State {
 	ret.output = append(ret.output, &ret)
 	return ret
 }
+
+// Creates and returns a state that _always_ has a zero-length match.
+func zeroLengthMatchState() State {
+	start := newState()
+	start.content = newContents(EPSILON)
+	start.isEmpty = true
+	start.assert = ALWAYS_TRUE
+	return start
+}