Wrote function to check if the assertion of a state is true

nfa.go

@@ -25,8 +25,9 @@ type State struct {
 	zeroMatchFound bool             // Whether or not the state has been used for a zero-length match - only relevant for zero states
 }
 
-// Returns true if the contents of 's' contain the value at the given index of the given string
+// Checks if the given state's assertion is true. Returns true if the given
-func (s State) contentContains(str []rune, idx int) bool {
+// state doesn't have an assertion.
+func (s State) checkAssertion(str []rune, idx int) bool {
 	if s.assert == SOS {
 		return idx == 0
 	}
@@ -39,6 +40,14 @@ func (s State) contentContains(str []rune, idx int) bool {
 	if s.assert == NONWBOUND {
 		return !isWordBoundary(str, idx)
 	}
+	return true
+}
+
+// Returns true if the contents of 's' contain the value at the given index of the given string
+func (s State) contentContains(str []rune, idx int) bool {
+	if s.assert != NONE {
+		return s.checkAssertion(str, idx)
+	}
 	// Default - s.assert must be NONE
 	return slices.Contains(s.content, int(str[idx]))
 }