text: // Copyright 2006 The Closure Library Authors. All Rights Reserved.
  //
  // 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.
  
  /**
   * @fileoverview Detect Grapheme Cluster Break in a pair of codepoints. Follows
   * Unicode 5.1 UAX#29.
   *
   */
  
  goog.provide('goog.i18n.GraphemeBreak');
  goog.require('goog.structs.InversionMap');
  
  
  /**
   * Enum for all Grapheme Cluster Break properties.
   * These enums directly corresponds to Grapheme_Cluster_Break property values
   * mentioned in http://unicode.org/reports/tr29 table 2.
   *
   * CR and LF are moved to the bottom of the list because they occur only once
   * and so good candidates to take 2 decimal digit values.
   * @enum {number}
   * @protected
   */
  goog.i18n.GraphemeBreak.property = {
    ANY: 0,
    CONTROL: 1,
    EXTEND: 2,
    PREPEND: 3,
    SPACING_MARK: 4,
    L: 5,
    V: 6,
    T: 7,
    LV: 8,
    LVT: 9,
    CR: 10,
    LF: 11
  };
  
  
  /**
   * Grapheme Cluster Break property values for all codepoints as inversion map.
   * Constructed lazily.
   *
   * @type {goog.structs.InversionMap}
   * @private
   */
  goog.i18n.GraphemeBreak.inversions_ = null;
  
  
  /**
   * There are two kinds of grapheme clusters: 1) Legacy 2)Extended. This method
   * is to check for legacy rules.
   *
   * @param {number} prop_a The property enum value of the first character.
   * @param {number} prop_b The property enum value of the second character.
   * @return {boolean} True if a & b do not form a cluster; False otherwise.
   * @private
   */
  goog.i18n.GraphemeBreak.applyLegacyBreakRules_ = function(prop_a, prop_b) {
  
    var prop = goog.i18n.GraphemeBreak.property;
  
    if (prop_a == prop.CR && prop_b == prop.LF) {
      return false;
    }
    if (prop_a == prop.CONTROL || prop_a == prop.CR || prop_a == prop.LF) {
      return true;
    }
    if (prop_b == prop.CONTROL || prop_b == prop.CR || prop_b == prop.LF) {
      return true;
    }
    if ((prop_a == prop.L) &&
      (prop_b == prop.L || prop_b == prop.V ||
       prop_b == prop.LV || prop_b == prop.LVT)) {
      return false;
    }
    if ((prop_a == prop.LV || prop_a == prop.V) &&
      (prop_b == prop.V || prop_b == prop.T)) {
      return false;
    }
    if ((prop_a == prop.LVT || prop_a == prop.T) && (prop_b == prop.T)) {
      return false;
    }
    if (prop_b == prop.EXTEND) {
      return false;
    }
    return true;
  };
  
  
  /**
   * Method to return property enum value of the codepoint. If it is Hangul LV or
   * LVT, then it is computed; for the rest it is picked from the inversion map.
   * @param {number} acode The code point value of the character.
   * @return {number} Property enum value of codepoint.
   * @private
   */
  goog.i18n.GraphemeBreak.getBreakProp_ = function(acode) {
    if (0xAC00 <= acode && acode <= 0xD7A3) {
      var prop = goog.i18n.GraphemeBreak.property;
      if (acode % 0x1C == 0x10) {
        return prop.LV;
      }
      return prop.LVT;
    } else {
      if (!goog.i18n.GraphemeBreak.inversions_) {
        goog.i18n.GraphemeBreak.inversions_ = new goog.structs.InversionMap(
            [0, 10, 1, 2, 1, 18, 95, 33, 13, 1, 594, 112, 275, 7, 263, 45, 1, 1,
             1, 2, 1, 2, 1, 1, 56, 4, 12, 11, 48, 20, 17, 1, 101, 7, 1, 7, 2, 2,
             1, 4, 33, 1, 1, 1, 30, 27, 91, 11, 58, 9, 269, 2, 1, 56, 1, 1, 3, 8,
             4, 1, 3, 4, 13, 2, 29, 1, 2, 56, 1, 1, 1, 2, 6, 6, 1, 9, 1, 10, 2,
             29, 2, 1, 56, 2, 3, 17, 30, 2, 3, 14, 1, 56, 1, 1, 3, 8, 4, 1, 20,
             2, 29, 1, 2, 56, 1, 1, 2, 1, 6, 6, 11, 10, 2, 30, 1, 59, 1, 1, 1,
             12, 1, 9, 1, 41, 3, 58, 3, 5, 17, 11, 2, 30, 2, 56, 1, 1, 1, 1, 2,
             1, 3, 1, 5, 11, 11, 2, 30, 2, 58, 1, 2, 5, 7, 11, 10, 2, 30, 2, 70,
             6, 2, 6, 7, 19, 2, 60, 11, 5, 5, 1, 1, 8, 97, 13, 3, 5, 3, 6, 74, 2,
             27, 1, 1, 1, 1, 1, 4, 2, 49, 14, 1, 5, 1, 2, 8, 45, 9, 1, 100, 2, 4,
             1, 6, 1, 2, 2, 2, 23, 2, 2, 4, 3, 1, 3, 2, 7, 3, 4, 13, 1, 2, 2, 6,
             1, 1, 1, 112, 96, 72, 82, 357, 1, 946, 3, 29, 3, 29, 2, 30, 2, 64,
             2, 1, 7, 8, 1, 2, 11, 9, 1, 45, 3, 155, 1, 118, 3, 4, 2, 9, 1, 6, 3,
             116, 17, 7, 2, 77, 2, 3, 228, 4, 1, 47, 1, 1, 5, 1, 1, 5, 1, 2, 38,
             9, 12, 2, 1, 30, 1, 4, 2, 2, 1, 121, 8, 8, 2, 2, 392, 64, 523, 1, 2,
             2, 24, 7, 49, 16, 96, 33, 3311, 32, 554, 6, 105, 2, 30164, 4, 9, 2,
             388, 1, 3, 1, 4, 1, 23, 2, 2, 1, 88, 2, 50, 16, 1, 97, 8, 25, 11, 2,
             213, 6, 2, 2, 2, 2, 12, 1, 8, 1, 1, 434, 11172, 1116, 1024, 6942, 1,
             737, 16, 16, 7, 216, 1, 158, 2, 89, 3, 513, 1, 2051, 15, 40, 8,
             50981, 1, 1, 3, 3, 1, 5, 8, 8, 2, 7, 30, 4, 148, 3, 798140, 255],
            [1, 11, 1, 10, 1, 0, 1, 0, 1, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0,
             2, 0, 1, 0, 2, 0, 2, 0, 2, 0, 2, 1, 2, 0, 2, 0, 2, 0, 1, 0, 2, 0, 2,
             0, 2, 0, 2, 0, 2, 4, 0, 2, 0, 4, 2, 4, 2, 0, 2, 0, 2, 0, 2, 4, 0, 2,
             0, 2, 4, 2, 4, 2, 0, 2, 0, 2, 0, 2, 4, 0, 2, 4, 2, 0, 2, 0, 2, 4, 0,
             2, 0, 4, 2, 4, 2, 0, 2, 0, 2, 4, 0, 2, 0, 2, 4, 2, 4, 2, 0, 2, 0, 2,
             0, 2, 4, 2, 4, 2, 0, 2, 0, 4, 0, 2, 4, 2, 0, 2, 0, 4, 0, 2, 0, 4, 2,
             4, 2, 4, 2, 4, 2, 0, 2, 0, 4, 0, 2, 4, 2, 4, 2, 0, 2, 0, 4, 0, 2, 4,
             2, 4, 2, 4, 0, 2, 0, 3, 2, 0, 2, 0, 2, 0, 3, 0, 2, 0, 2, 0, 2, 0, 2,
             0, 2, 0, 4, 0, 2, 4, 2, 0, 2, 0, 2, 0, 2, 0, 4, 2, 4, 2, 4, 2, 4, 2,
             0, 4, 2, 0, 2, 0, 4, 0, 4, 0, 2, 0, 2, 4, 2, 4, 2, 0, 4, 0, 5, 6, 7,
             0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 1, 4, 2, 4, 2, 4, 2, 0, 2, 0, 2, 0,
             2, 0, 2, 4, 2, 4, 2, 4, 2, 0, 4, 0, 4, 0, 2, 4, 0, 2, 4, 0, 2, 4, 2,
             4, 2, 4, 2, 4, 0, 2, 0, 2, 4, 0, 4, 2, 4, 2, 4, 0, 4, 2, 4, 2, 0, 2,
             0, 1, 2, 1, 0, 1, 0, 1, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0,
             2, 0, 2, 0, 4, 2, 4, 0, 4, 0, 4, 2, 0, 2, 0, 2, 4, 0, 2, 4, 2, 4, 2,
             0, 2, 0, 2, 4, 0, 9, 0, 2, 0, 2, 0, 2, 0, 2, 0, 1, 0, 2, 0, 1, 0, 2,
             0, 2, 0, 2, 0, 2, 4, 2, 0, 4, 2, 1, 2, 0, 2, 0, 2, 0, 2, 0, 1, 2],
            true);
      }
      return (/** @type {number} */
          goog.i18n.GraphemeBreak.inversions_.at(acode));
    }
  };
  
  
  /**
   * There are two kinds of grapheme clusters: 1) Legacy 2)Extended. This method
   * is to check for both using a boolean flag to switch between them.
   * @param {number} a The code point value of the first character.
   * @param {number} b The code point value of the second character.
   * @param {boolean=} opt_extended If true, indicates extended grapheme cluster;
   *     If false, indicates legacy cluster.
   * @return {boolean} True if a & b do not form a cluster; False otherwise.
   */
  goog.i18n.GraphemeBreak.hasGraphemeBreak = function(a, b, opt_extended) {
  
    var prop_a = goog.i18n.GraphemeBreak.getBreakProp_(a);
    var prop_b = goog.i18n.GraphemeBreak.getBreakProp_(b);
    var prop = goog.i18n.GraphemeBreak.property;
  
    return goog.i18n.GraphemeBreak.applyLegacyBreakRules_(prop_a, prop_b) &&
      !(opt_extended && (prop_a == prop.PREPEND || prop_b == prop.SPACING_MARK));
  };
  