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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.

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/*
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1999.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Roger Lawrence
 *   Mike McCabe
 *   Igor Bukanov
 *   Ethan Hugg
 *   Bob Jervis
 *   Terry Lucas
 *   Milen Nankov
 *   Pascal-Louis Perez
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
 * case the provisions of the GPL are applicable instead of those above. If
 * you wish to allow use of your version of this file only under the terms of
 * the GPL and not to allow others to use your version of this file under the
 * MPL, indicate your decision by deleting the provisions above and replacing
 * them with the notice and other provisions required by the GPL. If you do
 * not delete the provisions above, a recipient may use your version of this
 * file under either the MPL or the GPL.
 *
 * ***** END LICENSE BLOCK ***** */

package com.google.javascript.rhino;

import com.google.common.annotations.GwtIncompatible;
import com.google.javascript.rhino.jstype.TernaryValue;

/**
 * Helper methods for parsing JavaScript.
 * These methods use unsupported features in GWT's emulation of java.lang.Character.
 *
 * TODO(moz): Add a GWT-compatible version in the super-source directory.
 */
@GwtIncompatible("Unsupported java.lang.Character fields")
public class TokenUtil {
  /* As defined in ECMA.  jsscan.c uses C isspace() (which allows
   * \v, I think.)  note that code in getChar() implicitly accepts
   * '\r' == \u000D as well.
   */
  public static boolean isJSSpace(int c) {
    if (c <= 127) {
      return c == 0x20 || c == 0x9 || c == 0xC || c == 0xB;
    } else {
      return c == 0xA0
          || Character.getType((char) c) == Character.SPACE_SEPARATOR;
    }
  }

  public static boolean isJSFormatChar(int c) {
    return c > 127 && Character.getType(c) == Character.FORMAT;
  }

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

  /**
   * Copied from Rhino's ScriptRuntime
   */
  public static TernaryValue isStrWhiteSpaceChar(int c) {
    switch (c) {
      case '\u000B': // 
        return TernaryValue.UNKNOWN;  // 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 (Character.getType(c) == Character.SPACE_SEPARATOR)
            ? TernaryValue.TRUE : TernaryValue.FALSE;
    }
  }
}