Source: anagram.js

/** @module anagram */
(function(exports) {
    'use strict';

    /* === Checker management === */

    /**
     * Proxy function to create an anagram checker.
     *
     * @param {boolean} stripDiacritics - <code>true</code> if diacritics should be removed,
     *         <code>false</code> otherwise (default = <code>true</code>).
     * @param {string} original - The original string.
     * @param {string} proposition - The anagram proposition.
     * @returns {Checker} A checker
     * @see {@link Checker}
     */
    exports.checker = function(stripDiacritics, original, proposition) {
        return new exports.Checker(stripDiacritics, original, proposition);
    };

    /**
     * Creates a new instance.
     * @class
     * @classdesc The checker is a utility to easily compare a source string and a proposed anagram.
     * <p/>
     * It comes with utilities to determine what characters have been used or not, and which were
     * not part of the original source.
     * <p/>
     * Non-letter characters are ignored, diacritics and ligatures can be removed to keep their
     * latin equivalent, or be considered as is.
     * <p/>
     * This checker is <strong>not</strong> case-sensitive.
     *
     * @param {boolean} stripDiacritics - <code>true</code> if diacritics should be removed,
     *         <code>false</code> otherwise (default = <code>true</code>).
     * @param {string} original - The original string.
     * @param {string} proposition - An anagram proposition.
     */
    exports.Checker = function(stripDiacritics, original, proposition) {
        this.stripDiacritics = typeof stripDiacritics === 'undefined' || stripDiacritics;
        this.updateOriginal(original);
        this.propose(proposition);
    };

    /**
     * Changes the diacritics behavior and updates the state accordingly.
     * <p/>
     * This means the available characters and diff are recomputed immediately.
     *
     * @param {boolean} stripDiacritics - <code>true</code> if diacritics should be removed,
     *         <code>false</code> otherwise (default = <code>true</code>).
     * @returns {Checker} The current instance
     */
    exports.Checker.prototype.updateStripDiacritics = function(stripDiacritics) {
        var strip = typeof stripDiacritics === 'undefined' || stripDiacritics;
        if (this.stripDiacritics !== strip) {
            this.stripDiacritics = strip;
            var recomputeDiff = false;
            if (this.original) {
                this.original = parse(this.original.str, strip);
                recomputeDiff = true;
            }
            if (this.proposition) {
                this.proposition = parse(this.proposition.str, strip);
                recomputeDiff = true;
            }
            if (recomputeDiff) {
                this.diff = diff(this.original, this.proposition);
            }
        }
        return this;
    };

    /**
     * Changes the original string and updates the state accordingly.
     * <p/>
     * This means the available characters and diff are recomputed immediately.
     *
     * @param {string} original - The original string.
     * @returns {Checker} The current instance
     */
    exports.Checker.prototype.updateOriginal = function(original) {
        if (!this.original || original !== this.original.str) {
            this.original = parse(original, this.stripDiacritics);
            this.diff = diff(this.original, this.proposition);
        }
        return this;
    };

    /**
     * Registers a string as a proposition for an anagram of the original string.
     * <p/>
     * The diff is immediately recomputed.
     *
     * @param {string} proposition - The anagram proposition.
     * @returns {Checker} The current instance
     */
    exports.Checker.prototype.propose = function(proposition) {
        if (!this.proposition || proposition !== this.proposition.str) {
            this.proposition = parse(proposition, this.stripDiacritics);
            this.diff = diff(this.original, this.proposition);
        }
        return this;
    };

    /**
     * Returns the current proposition for an anagram.
     *
     * @returns {string} The proposition
     */
    exports.Checker.prototype.getProposition = function() {
        return this.proposition.str;
    };

    /**
     * Returns the original string this checker checks anagrams for.
     *
     * @returns {string} The original string
     */
    exports.Checker.prototype.getOriginal = function() {
        return this.original.str;
    };

    /**
     * Returns an object containing the characters available for an anagram from the original
     * string.
     * <p/>
     * The result has a property for each character, and the corresponding value is the cardinality
     * of this character in the original string.
     * <p/>
     * If the diacritics stripping is active, this object will contain only latin letters.
     *
     * @returns {Object} An object containing the characters as properties and their cardinality as
     *         values
     */
    exports.Checker.prototype.getOriginalChars = function() {
        return this.original.map;
    };

    /**
     * Returns an object containing the characters available for an anagram from the original
     * string after having removed those used in the proposition.
     * <p/>
     * The result has a property for each character, and the corresponding value is the cardinality
     * of this character in the original string. If more instances of a character were used than
     * available in the original string, they will have a negative cardinality in the diff object.
     * <p/>
     * If the diacritics stripping is active, this object will contain only latin letters.
     *
     * @returns {Object} An object containing the characters as properties and their cardinality as
     *         values
     */
    exports.Checker.prototype.getDiff = function() {
        return this.diff;
    };

    /**
     * Checks whether the proposition is an anagram of the original string.
     * <p/>
     * If the diacritics stripping is inactive, the anagram must use the same diacritics as the
     * original string.
     *
     * @returns {boolean} <code>true</code> if the current proposition is an anagram of the original
     *         string, <code>false</code> otherwise
     */
    exports.Checker.prototype.isAnagram = function() {
        return isNoDiff(this.diff);
    };

    /* === Parsing/character listing functions === */

    function parse(str, strip) {
        var result = { str: str };

        if (str) {
            if (strip) {
                result.map = map(stripDiacritics(str));
            } else {
                result.map = map(str);
            }
        } else {
            result.map = {};
        }

        return result;
    }

    function map(str) {
        var source = str.toLowerCase().replace(new RegExp(disallowedCharacters, 'g'), ''),
            length = source.length,
            result = {};
        for (var i = 0; i < length; i++) {
            var letter = source.charAt(i);
            if (result.hasOwnProperty(letter)) {
                result[letter]++;
            } else {
                result[letter] = 1;
            }
        }
        return result;
    }

    /* === Diff functions === */

    function diff(src, prop) {
        var mapS = src ? src.map : {},
            mapP = prop ? prop.map : {},
            result = {};

        /* Clone the src map (should not contain any 0) */
        for (var propS in mapS) {
            if (mapS[propS] !== 0) {
                result[propS] = mapS[propS];
            }
        }

        /* Remove what was used in the proposition */
        for (var propP in mapP) {
            if (mapP[propP] !== 0) {
                if (result.hasOwnProperty(propP)) {
                    result[propP] -= mapP[propP];
                } else {
                    result[propP] = -mapP[propP];
                }
                // remove any property brought down to 0
                if (result[propP] === 0) {
                    delete result[propP];
                }
            }
        }

        /* That's it! */
        return result;
    }

    function isNoDiff(diff) {
        for (var property in diff) {
            if (diff[property] !== 0) {
                return false;
            }
        }

        return true;
    }

    /* === Diacritics removal === */
    /* source at http://stackoverflow.com/questions/990904 */
    var defaultDiacriticsRemovalap = [
        {'base':'A', 'letters':'\u0041\u24B6\uFF21\u00C0\u00C1\u00C2\u1EA6\u1EA4\u1EAA\u1EA8\u00C3\u0100\u0102\u1EB0\u1EAE\u1EB4\u1EB2\u0226\u01E0\u00C4\u01DE\u1EA2\u00C5\u01FA\u01CD\u0200\u0202\u1EA0\u1EAC\u1EB6\u1E00\u0104\u023A\u2C6F'},
        {'base':'AA','letters':'\uA732'},
        {'base':'AE','letters':'\u00C6\u01FC\u01E2'},
        {'base':'AO','letters':'\uA734'},
        {'base':'AU','letters':'\uA736'},
        {'base':'AV','letters':'\uA738\uA73A'},
        {'base':'AY','letters':'\uA73C'},
        {'base':'B', 'letters':'\u0042\u24B7\uFF22\u1E02\u1E04\u1E06\u0243\u0182\u0181'},
        {'base':'C', 'letters':'\u0043\u24B8\uFF23\u0106\u0108\u010A\u010C\u00C7\u1E08\u0187\u023B\uA73E'},
        {'base':'D', 'letters':'\u0044\u24B9\uFF24\u1E0A\u010E\u1E0C\u1E10\u1E12\u1E0E\u0110\u018B\u018A\u0189\uA779'},
        {'base':'DZ','letters':'\u01F1\u01C4'},
        {'base':'Dz','letters':'\u01F2\u01C5'},
        {'base':'E', 'letters':'\u0045\u24BA\uFF25\u00C8\u00C9\u00CA\u1EC0\u1EBE\u1EC4\u1EC2\u1EBC\u0112\u1E14\u1E16\u0114\u0116\u00CB\u1EBA\u011A\u0204\u0206\u1EB8\u1EC6\u0228\u1E1C\u0118\u1E18\u1E1A\u0190\u018E'},
        {'base':'F', 'letters':'\u0046\u24BB\uFF26\u1E1E\u0191\uA77B'},
        {'base':'G', 'letters':'\u0047\u24BC\uFF27\u01F4\u011C\u1E20\u011E\u0120\u01E6\u0122\u01E4\u0193\uA7A0\uA77D\uA77E'},
        {'base':'H', 'letters':'\u0048\u24BD\uFF28\u0124\u1E22\u1E26\u021E\u1E24\u1E28\u1E2A\u0126\u2C67\u2C75\uA78D'},
        {'base':'I', 'letters':'\u0049\u24BE\uFF29\u00CC\u00CD\u00CE\u0128\u012A\u012C\u0130\u00CF\u1E2E\u1EC8\u01CF\u0208\u020A\u1ECA\u012E\u1E2C\u0197'},
        {'base':'J', 'letters':'\u004A\u24BF\uFF2A\u0134\u0248'},
        {'base':'K', 'letters':'\u004B\u24C0\uFF2B\u1E30\u01E8\u1E32\u0136\u1E34\u0198\u2C69\uA740\uA742\uA744\uA7A2'},
        {'base':'L', 'letters':'\u004C\u24C1\uFF2C\u013F\u0139\u013D\u1E36\u1E38\u013B\u1E3C\u1E3A\u0141\u023D\u2C62\u2C60\uA748\uA746\uA780'},
        {'base':'LJ','letters':'\u01C7'},
        {'base':'Lj','letters':'\u01C8'},
        {'base':'M', 'letters':'\u004D\u24C2\uFF2D\u1E3E\u1E40\u1E42\u2C6E\u019C'},
        {'base':'N', 'letters':'\u004E\u24C3\uFF2E\u01F8\u0143\u00D1\u1E44\u0147\u1E46\u0145\u1E4A\u1E48\u0220\u019D\uA790\uA7A4'},
        {'base':'NJ','letters':'\u01CA'},
        {'base':'Nj','letters':'\u01CB'},
        {'base':'O', 'letters':'\u004F\u24C4\uFF2F\u00D2\u00D3\u00D4\u1ED2\u1ED0\u1ED6\u1ED4\u00D5\u1E4C\u022C\u1E4E\u014C\u1E50\u1E52\u014E\u022E\u0230\u00D6\u022A\u1ECE\u0150\u01D1\u020C\u020E\u01A0\u1EDC\u1EDA\u1EE0\u1EDE\u1EE2\u1ECC\u1ED8\u01EA\u01EC\u00D8\u01FE\u0186\u019F\uA74A\uA74C'},
        {'base':'OI','letters':'\u01A2'},
        {'base':'OO','letters':'\uA74E'},
        {'base':'OU','letters':'\u0222'},
        {'base':'OE','letters':'\u008C\u0152'},
        {'base':'oe','letters':'\u009C\u0153'},
        {'base':'P', 'letters':'\u0050\u24C5\uFF30\u1E54\u1E56\u01A4\u2C63\uA750\uA752\uA754'},
        {'base':'Q', 'letters':'\u0051\u24C6\uFF31\uA756\uA758\u024A'},
        {'base':'R', 'letters':'\u0052\u24C7\uFF32\u0154\u1E58\u0158\u0210\u0212\u1E5A\u1E5C\u0156\u1E5E\u024C\u2C64\uA75A\uA7A6\uA782'},
        {'base':'S', 'letters':'\u0053\u24C8\uFF33\u1E9E\u015A\u1E64\u015C\u1E60\u0160\u1E66\u1E62\u1E68\u0218\u015E\u2C7E\uA7A8\uA784'},
        {'base':'T', 'letters':'\u0054\u24C9\uFF34\u1E6A\u0164\u1E6C\u021A\u0162\u1E70\u1E6E\u0166\u01AC\u01AE\u023E\uA786'},
        {'base':'TZ','letters':'\uA728'},
        {'base':'U', 'letters':'\u0055\u24CA\uFF35\u00D9\u00DA\u00DB\u0168\u1E78\u016A\u1E7A\u016C\u00DC\u01DB\u01D7\u01D5\u01D9\u1EE6\u016E\u0170\u01D3\u0214\u0216\u01AF\u1EEA\u1EE8\u1EEE\u1EEC\u1EF0\u1EE4\u1E72\u0172\u1E76\u1E74\u0244'},
        {'base':'V', 'letters':'\u0056\u24CB\uFF36\u1E7C\u1E7E\u01B2\uA75E\u0245'},
        {'base':'VY','letters':'\uA760'},
        {'base':'W', 'letters':'\u0057\u24CC\uFF37\u1E80\u1E82\u0174\u1E86\u1E84\u1E88\u2C72'},
        {'base':'X', 'letters':'\u0058\u24CD\uFF38\u1E8A\u1E8C'},
        {'base':'Y', 'letters':'\u0059\u24CE\uFF39\u1EF2\u00DD\u0176\u1EF8\u0232\u1E8E\u0178\u1EF6\u1EF4\u01B3\u024E\u1EFE'},
        {'base':'Z', 'letters':'\u005A\u24CF\uFF3A\u0179\u1E90\u017B\u017D\u1E92\u1E94\u01B5\u0224\u2C7F\u2C6B\uA762'},
        {'base':'a', 'letters':'\u0061\u24D0\uFF41\u1E9A\u00E0\u00E1\u00E2\u1EA7\u1EA5\u1EAB\u1EA9\u00E3\u0101\u0103\u1EB1\u1EAF\u1EB5\u1EB3\u0227\u01E1\u00E4\u01DF\u1EA3\u00E5\u01FB\u01CE\u0201\u0203\u1EA1\u1EAD\u1EB7\u1E01\u0105\u2C65\u0250'},
        {'base':'aa','letters':'\uA733'},
        {'base':'ae','letters':'\u00E6\u01FD\u01E3'},
        {'base':'ao','letters':'\uA735'},
        {'base':'au','letters':'\uA737'},
        {'base':'av','letters':'\uA739\uA73B'},
        {'base':'ay','letters':'\uA73D'},
        {'base':'b', 'letters':'\u0062\u24D1\uFF42\u1E03\u1E05\u1E07\u0180\u0183\u0253'},
        {'base':'c', 'letters':'\u0063\u24D2\uFF43\u0107\u0109\u010B\u010D\u00E7\u1E09\u0188\u023C\uA73F\u2184'},
        {'base':'d', 'letters':'\u0064\u24D3\uFF44\u1E0B\u010F\u1E0D\u1E11\u1E13\u1E0F\u0111\u018C\u0256\u0257\uA77A'},
        {'base':'dz','letters':'\u01F3\u01C6'},
        {'base':'e', 'letters':'\u0065\u24D4\uFF45\u00E8\u00E9\u00EA\u1EC1\u1EBF\u1EC5\u1EC3\u1EBD\u0113\u1E15\u1E17\u0115\u0117\u00EB\u1EBB\u011B\u0205\u0207\u1EB9\u1EC7\u0229\u1E1D\u0119\u1E19\u1E1B\u0247\u025B\u01DD'},
        {'base':'f', 'letters':'\u0066\u24D5\uFF46\u1E1F\u0192\uA77C'},
        {'base':'g', 'letters':'\u0067\u24D6\uFF47\u01F5\u011D\u1E21\u011F\u0121\u01E7\u0123\u01E5\u0260\uA7A1\u1D79\uA77F'},
        {'base':'h', 'letters':'\u0068\u24D7\uFF48\u0125\u1E23\u1E27\u021F\u1E25\u1E29\u1E2B\u1E96\u0127\u2C68\u2C76\u0265'},
        {'base':'hv','letters':'\u0195'},
        {'base':'i', 'letters':'\u0069\u24D8\uFF49\u00EC\u00ED\u00EE\u0129\u012B\u012D\u00EF\u1E2F\u1EC9\u01D0\u0209\u020B\u1ECB\u012F\u1E2D\u0268\u0131'},
        {'base':'j', 'letters':'\u006A\u24D9\uFF4A\u0135\u01F0\u0249'},
        {'base':'k', 'letters':'\u006B\u24DA\uFF4B\u1E31\u01E9\u1E33\u0137\u1E35\u0199\u2C6A\uA741\uA743\uA745\uA7A3'},
        {'base':'l', 'letters':'\u006C\u24DB\uFF4C\u0140\u013A\u013E\u1E37\u1E39\u013C\u1E3D\u1E3B\u017F\u0142\u019A\u026B\u2C61\uA749\uA781\uA747'},
        {'base':'lj','letters':'\u01C9'},
        {'base':'m', 'letters':'\u006D\u24DC\uFF4D\u1E3F\u1E41\u1E43\u0271\u026F'},
        {'base':'n', 'letters':'\u006E\u24DD\uFF4E\u01F9\u0144\u00F1\u1E45\u0148\u1E47\u0146\u1E4B\u1E49\u019E\u0272\u0149\uA791\uA7A5'},
        {'base':'nj','letters':'\u01CC'},
        {'base':'o', 'letters':'\u006F\u24DE\uFF4F\u00F2\u00F3\u00F4\u1ED3\u1ED1\u1ED7\u1ED5\u00F5\u1E4D\u022D\u1E4F\u014D\u1E51\u1E53\u014F\u022F\u0231\u00F6\u022B\u1ECF\u0151\u01D2\u020D\u020F\u01A1\u1EDD\u1EDB\u1EE1\u1EDF\u1EE3\u1ECD\u1ED9\u01EB\u01ED\u00F8\u01FF\u0254\uA74B\uA74D\u0275'},
        {'base':'oi','letters':'\u01A3'},
        {'base':'ou','letters':'\u0223'},
        {'base':'oo','letters':'\uA74F'},
        {'base':'p', 'letters':'\u0070\u24DF\uFF50\u1E55\u1E57\u01A5\u1D7D\uA751\uA753\uA755'},
        {'base':'q', 'letters':'\u0071\u24E0\uFF51\u024B\uA757\uA759'},
        {'base':'r', 'letters':'\u0072\u24E1\uFF52\u0155\u1E59\u0159\u0211\u0213\u1E5B\u1E5D\u0157\u1E5F\u024D\u027D\uA75B\uA7A7\uA783'},
        {'base':'s', 'letters':'\u0073\u24E2\uFF53\u00DF\u015B\u1E65\u015D\u1E61\u0161\u1E67\u1E63\u1E69\u0219\u015F\u023F\uA7A9\uA785\u1E9B'},
        {'base':'t', 'letters':'\u0074\u24E3\uFF54\u1E6B\u1E97\u0165\u1E6D\u021B\u0163\u1E71\u1E6F\u0167\u01AD\u0288\u2C66\uA787'},
        {'base':'tz','letters':'\uA729'},
        {'base':'u', 'letters':'\u0075\u24E4\uFF55\u00F9\u00FA\u00FB\u0169\u1E79\u016B\u1E7B\u016D\u00FC\u01DC\u01D8\u01D6\u01DA\u1EE7\u016F\u0171\u01D4\u0215\u0217\u01B0\u1EEB\u1EE9\u1EEF\u1EED\u1EF1\u1EE5\u1E73\u0173\u1E77\u1E75\u0289'},
        {'base':'v', 'letters':'\u0076\u24E5\uFF56\u1E7D\u1E7F\u028B\uA75F\u028C'},
        {'base':'vy','letters':'\uA761'},
        {'base':'w', 'letters':'\u0077\u24E6\uFF57\u1E81\u1E83\u0175\u1E87\u1E85\u1E98\u1E89\u2C73'},
        {'base':'x', 'letters':'\u0078\u24E7\uFF58\u1E8B\u1E8D'},
        {'base':'y', 'letters':'\u0079\u24E8\uFF59\u1EF3\u00FD\u0177\u1EF9\u0233\u1E8F\u00FF\u1EF7\u1E99\u1EF5\u01B4\u024F\u1EFF'},
        {'base':'z', 'letters':'\u007A\u24E9\uFF5A\u017A\u1E91\u017C\u017E\u1E93\u1E95\u01B6\u0225\u0240\u2C6C\uA763'}
    ];

    var diacriticsMap = {};
    var disallowedCharacters = '[^a-zA-Z';
    for (var i = 0; i < defaultDiacriticsRemovalap.length; i++){
        var letters = defaultDiacriticsRemovalap[i].letters;
        disallowedCharacters += letters;
        for (var j = 0; j < letters.length; j++){
            diacriticsMap[letters.charAt(j)] = defaultDiacriticsRemovalap[i].base;
        }
    }
    disallowedCharacters += ']+';

    // "what?" version ... http://jsperf.com/diacritics/12
    function stripDiacritics(str) {
        return str ? str.replace(/[^\u0000-\u007E]/g, function(a){
           return diacriticsMap[a] || a;
        }) : str;
    }
})(window.anagram = window.anagram || {});