Defined postfixNodes for LPAREN and RPAREN

postfixNode.go

@@ -104,6 +104,14 @@ func newPostfixNode(contents ...rune) postfixNode {
 			to_return.nodetype = CHARACTER
 		}
 		to_return.contents = append(to_return.contents, contents...)
+
+		// Special cases for LPAREN and RPAREN - they have special characters defined for them
+		if to_return.nodetype == LPAREN {
+			to_return.contents = []rune{LPAREN_CHAR}
+		}
+		if to_return.nodetype == RPAREN {
+			to_return.contents = []rune{RPAREN_CHAR}
+		}
 	}
 	return to_return
 }