com.google.javascript.jscomp.gwt.super.com.google.javascript.rhino.TokenUtil Maven / Gradle / Ivy

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Closure Compiler is a JavaScript optimizing compiler. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what's left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls. It is used in many of Google's JavaScript apps, including Gmail, Google Web Search, Google Maps, and Google Docs. This binary checks for style issues such as incorrect or missing JSDoc usage, and missing goog.require() statements. It does not do more advanced checks such as typechecking.

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/*
 * Copyright 2015 The Closure Compiler Authors.
 *
 * 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.javascript.rhino;

import com.google.javascript.rhino.jstype.TernaryValue;
import jsinterop.annotations.JsPackage;
import jsinterop.annotations.JsType;

/**
 * Helper methods for parsing JavaScript.
 *
 * @author [email protected] (Michael Zhou)
 */
public class TokenUtil {
  @JsType(isNative = true, namespace = JsPackage.GLOBAL, name = "RegExp")
  private static class RegExp {
    RegExp(String string) {}
    native boolean test(String string);
    native boolean test(int charcode);
  }

  // TODO(moz): Support full range of valid characters.
  private static final RegExp JS_IDENTIFIER_REGEX = new RegExp("^[a-zA-Z_$][\\w$]*$");
  private static final RegExp WHITE_SPACE_REGEX = new RegExp("\\s");

  static boolean isJSIdentifier(String s) {
    return JS_IDENTIFIER_REGEX.test(s);
  }

  public static boolean isJSSpace(int c) {
    if (c <= 127) {
      return c == 0x20 || c == 0x9 || c == 0xC || c == 0xB;
    } else {
      return c == 0xA0; // TODO(moz): Correct this.
    }
  }

  public static boolean isJSFormatChar(int c) {
    return c > 127; // TODO(moz): Correct this.
  }

  public static boolean isWhitespace(int c) {
    return WHITE_SPACE_REGEX.test(c);
  };

  public static TernaryValue isStrWhiteSpaceChar(int c) {
    switch (c) {
      case '\u000B': // 
        return TernaryValue.UNKNOWN;  // Legacy IE says "no", ECMAScript says "yes"
      case ' ': // 
      case '\n': // 
      case '\r': // 
      case '\t': // 
      case '\u00A0': // 
      case '\u000C': // 
      case '\u2028': // 
      case '\u2029': // 
      case '\uFEFF': // 
        return TernaryValue.TRUE;
      default:
        return TernaryValue.FALSE; // TODO(moz): Correct this.
    }
  }
}