Added unicode support to dot metacharacter - it now matches _any_ unicode character (almost)

nfa.go

@@ -23,6 +23,7 @@ type State struct {
 	isKleene       bool             // Identifies whether current node is a 0-state representing Kleene star
 	assert         assertType       // Type of assertion of current node - NONE means that the node doesn't assert anything
 	zeroMatchFound bool             // Whether or not the state has been used for a zero-length match - only relevant for zero states
+	isDot          bool             // Whether or not the state represents a 'dot' metacharacter. A 'dot' node doesn't store any contents directly, as it would take up too much space
 }
 
 // Clones the NFA starting from the given state.
@@ -94,6 +95,9 @@ func (s State) contentContains(str []rune, idx int) bool {
 	if s.assert != NONE {
 		return s.checkAssertion(str, idx)
 	}
+	if s.isDot {
+		return !slices.Contains(notDotChars, str[idx])
+	}
 	// Default - s.assert must be NONE
 	return slices.Contains(s.content, int(str[idx]))
 }
@@ -116,7 +120,12 @@ func (s State) matchesFor(str []rune, idx int) ([]*State, int) {
 	if s.assert == NONWBOUND && isWordBoundary(str, idx) {
 		return make([]*State, 0), -1
 	}
-	return s.transitions[int(str[idx])], len(s.transitions[int(str[idx])])
+	listTransitions := s.transitions[int(str[idx])]
+	for _, dest := range s.transitions[int(ANY_CHAR)] {
+		listTransitions = append(listTransitions, dest)
+	}
+	numTransitions := len(listTransitions)
+	return listTransitions, numTransitions
 }
 
 type NFA struct {