Added node types for left and right parentheses

postfixNode.go

@@ -1,6 +1,8 @@
 package main
 
-import "slices"
+import (
+	"slices"
+)
 
 type NodeType int
 
@@ -13,6 +15,8 @@ const (
 	QUESTION
 	PLUS
 	ASSERTION
+	LPAREN
+	RPAREN
 )
 
 var INFINITE_REPS int = -1 // Represents infinite reps eg. the end range in {5,}
@@ -20,8 +24,8 @@ var INFINITE_REPS int = -1 // Represents infinite reps eg. the end range in {5,}
 type postfixNode struct {
 	nodetype  NodeType
 	contents  []rune // Contents of the node - the length of this would only be >1 if the node represents a character class
-	startReps int    // How many times the node should be repeated - used with numeric specifiers
+	startReps int    // Minimum number of times the node should be repeated - used with numeric specifiers
-	endReps   int
+	endReps   int    // Maximum number of times the node should be repeated - used with numeric specifiers
 }
 
 // Creates a new escaped node - the given character is assumed to have been preceded by a backslash
@@ -89,6 +93,10 @@ func newPostfixNode(contents ...rune) postfixNode {
 			to_return.nodetype = CONCATENATE
 		case '^', '$':
 			to_return.nodetype = ASSERTION
+		case '(':
+			to_return.nodetype = LPAREN
+		case ')':
+			to_return.nodetype = RPAREN
 		default:
 			to_return.nodetype = CHARACTER
 		}