Guid.js

var Guid = (function() {
    function Guid(guid) {
        var guid = guid || "";
        guid = [].filter.call(guid.toLowerCase(), function(ch) {
            return (ch >= "0") && (ch <= "f");
        }).join("");
        if (guid.length == 0) {
            this._isNull = true;
            guid = "000000000000000000000000000";
        }
        else {
            if (guid.length != 32) {
                throw ("invalid input [" + guid + "]");
            }
            this._isNull = false;
        }
        this._tuple = [[0,8],[8,16],[16,24],[24,32]].map(function(s) {
            return parseInt(guid.slice(s[0], s[1]), 16);
        });
    }

    Guid.prototype.isNull = function() {
        return this._isNull;
    };

    Guid.prototype.toString = function() {
        var toString16 = function(t) {
            var result = t.toString(16);
            while (result.length < 8) {
              result = "0" + result;
            }
            return result;
        };
        var tuple = this._tuple.map(toString16);
        return (tuple[0] + "-" +
            tuple[1].slice(0, 4) + "-" +
            tuple[1].slice(4, 8) + "-" +
            tuple[2].slice(0, 4) + "-" +
            tuple[2].slice(4, 8) + tuple[3]);
    };

    // ret<0: this<rhs, ret>0: this>rhs, ret=0: this=rhs
    Guid.prototype.compare = function(rhs) {
        var idx;
        for (idx = 0; idx < 4; idx++) {
          if (this._tuple[idx] < rhs._tuple[idx]) {
              return -1;
          }
          else if (this._tuple[idx] > rhs._tuple[idx]) {
              return 1;
          }
        }
        return 0; 
    };

    Guid.prototype.equals = function(rhs) {
        return (this.compare(rhs) == 0);
    }

    return Guid;
})();

if (typeof module === "object") { module.exports = Guid; }
if (typeof define === "function" && define.amd) { define(Guid); }

/*
 * var a = new Guid("{7fff-26bf-9527-4af9-8aa7-8b6c24d65bc9}");
 * var b = new Guid("{f34cc3ca-38b1-4b93-96a2-7307c5c6704f}");
 * var c = new Guid("{0db9b413-5130-4457-8735-be10d18b53e3}");
 * var d = new Guid("7fff-26bf-9527-4af9-8aa7-8b6c24d65bc9");
 * 
 * console.log("a : " + a);
 * console.log("b : " + b);
 * console.log("c : " + c);
 * console.log("d : " + d);
 * console.log("a <=> b : " + a.compare(b));
 * console.log("a <=> d : " + a.compare(d));
 * 
 * var i = new Guid("7fff-26bf-9527-4af9-8aa7-8b6c29");
 */