| /* |
| * Copyright 2008 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.gwt.dev.js.ast; |
| |
| /** |
| * A JavaScript unary operator. |
| */ |
| public enum JsUnaryOperator implements JsOperator { |
| /* |
| * Precedence indices from "JavaScript - The Definitive Guide" 4th Edition |
| * (page 57) |
| */ |
| |
| BIT_NOT("~", 14, PREFIX), DEC("--", 14, POSTFIX | PREFIX), DELETE("delete", |
| 14, PREFIX), INC("++", 14, POSTFIX | PREFIX), NEG("-", 14, PREFIX), POS( |
| "+", 14, PREFIX), NOT("!", 14, PREFIX), TYPEOF("typeof", 14, PREFIX), VOID( |
| "void", 14, PREFIX); |
| |
| private final int mask; |
| |
| private final int precedence; |
| |
| private final String symbol; |
| |
| private JsUnaryOperator(String symbol, int precedence, int mask) { |
| this.symbol = symbol; |
| this.precedence = precedence; |
| this.mask = mask; |
| } |
| |
| public int getPrecedence() { |
| return precedence; |
| } |
| |
| public String getSymbol() { |
| return symbol; |
| } |
| |
| public boolean isKeyword() { |
| return this == DELETE || this == TYPEOF || this == VOID; |
| } |
| |
| public boolean isLeftAssociative() { |
| return (mask & LEFT) != 0; |
| } |
| |
| public boolean isModifying() { |
| return this == DEC || this == INC || this == DELETE; |
| } |
| |
| public boolean isPrecedenceLessThan(JsOperator other) { |
| return precedence < other.getPrecedence(); |
| } |
| |
| public boolean isValidInfix() { |
| return (mask & INFIX) != 0; |
| } |
| |
| public boolean isValidPostfix() { |
| return (mask & POSTFIX) != 0; |
| } |
| |
| public boolean isValidPrefix() { |
| return (mask & PREFIX) != 0; |
| } |
| |
| @Override |
| public String toString() { |
| return symbol; |
| } |
| } |