Changed generation of characters for non-whitespace, non-digit and non-word characters - it's basically an inverted character class now

postfixNode.go

@@ -1,9 +1,5 @@
 package main
 
-import (
-	"slices"
-)
-
 type NodeType int
 
 // This is a list of the possible node types
@@ -39,27 +35,21 @@ func newEscapedNode(c rune) postfixNode {
 	case 's': // Whitespace
 		toReturn.nodetype = CHARACTER
 		toReturn.contents = append(toReturn.contents, whitespaceChars...)
-	case 'S': // Non-whitespace - I am doing this in a fancy way, generating all dot characters, then removing whitespace characters from it
-		toReturn.nodetype = CHARACTER
-		toReturn.contents = append(toReturn.contents, slices.DeleteFunc(dotChars(), func(r rune) bool {
-			return slices.Contains(whitespaceChars, r)
-		})...)
+	case 'S': // Non-whitespace
+		toReturn = newPostfixDotNode()
+		toReturn.except = append([]rune{}, whitespaceChars...)
 	case 'd': // Digits
 		toReturn.nodetype = CHARACTER
 		toReturn.contents = append(toReturn.contents, digitChars...)
-	case 'D': // Non-digits - same fancy way as 'S'
-		toReturn.nodetype = CHARACTER
-		toReturn.contents = append(toReturn.contents, slices.DeleteFunc(dotChars(), func(r rune) bool {
-			return slices.Contains(digitChars, r)
-		})...)
+	case 'D': // Non-digits
+		toReturn = newPostfixDotNode()
+		toReturn.except = append([]rune{}, digitChars...)
 	case 'w': // word character
 		toReturn.nodetype = CHARACTER
 		toReturn.contents = append(toReturn.contents, wordChars...)
-	case 'W': // Non-word character - same fancy way as 'S' and 'D'
-		toReturn.nodetype = CHARACTER
-		toReturn.contents = append(toReturn.contents, slices.DeleteFunc(dotChars(), func(r rune) bool {
-			return slices.Contains(wordChars, r)
-		})...)
+	case 'W': // Non-word character
+		toReturn = newPostfixDotNode()
+		toReturn.except = append([]rune{}, wordChars...)
 	case 'b', 'B':
 		toReturn.nodetype = ASSERTION
 		toReturn.contents = append(toReturn.contents, c)