/*Array*/

A = function(){
    
    var ret = {
        isArray: function( obj ) {
            return Object.prototype.toString.call(obj) === "[object Array]";
        },
        indexOf: function( array, elt, from ){
            if (array.indexOf) {
                return isNaN(from) ? array.indexOf(elt) : array.indexOf(elt, from);
            } else {
                var len = array.length;
                from = isNaN(from) ? 0
                    : from < 0 ? Math.ceil(from) + len : Math.floor(from);
                
                for ( ; from < len; from++ ) { if ( array[from] === elt ) return from; }
                return -1;
            }
        },
        lastIndexOf: function( array, elt, from ){
            if (array.lastIndexOf) {
                return isNaN(from) ? array.lastIndexOf(elt) : array.lastIndexOf(elt, from);
            } else {
                var len = array.length;
                from = isNaN(from) || from >= len - 1 ? len - 1
                    : from < 0 ? Math.ceil(from) + len : Math.floor(from);
                
                for ( ; from > -1; from-- ) { if ( array[from] === elt ) return from; }
                return -1;
            }
        }
    };
    
    function each( object, callback ) {
        if ( undefined === object.length ){
            for ( var name in object ) {
                if (false === callback( object[name], name, object )) break;
            }
        } else {
            for ( var i = 0, len = object.length; i < len; i++ ) {
                if (i in object) { if (false === callback(object[i], i, object )) break; }
            }
        }
    };
    
    each({
            forEach:function(object,callback,thisp){
              //大家看一下为什么上面的each函数，没有用this指针，这里还要用each.call,牛人请指点？？？
                each.call(thisp, object, function(){ callback.apply(thisp, arguments); } );
            },
            map: function( object, callback, thisp ){
                var ret = [];
                each.call( thisp, object, function(){ ret.push(callback.apply(thisp, arguments)); });
                return ret;
            },
            filter: function( object, callback, thisp ){
                var ret = [];
                each.call( thisp, object, function(item){
                        callback.apply(thisp, arguments) && ret.push(item);
                    });
                return ret;
            },
            every: function( object, callback, thisp ){
                var ret = true;
                each.call( thisp, object, function(){
                        if ( !callback.apply(thisp, arguments) ){ ret = false; return false; };
                    });
                return ret;
            },
            some: function( object, callback, thisp ){
                var ret = false;
                each.call( thisp, object, function(){
                        if ( callback.apply(thisp, arguments) ){ ret = true; return false; };
                    });
                return ret;
            }
        }, function(method, name){
            ret[name] = function( object, callback, thisp ){
                if (object[name]) {
                    return object[name]( callback, thisp );
                } else {
                    return method( object, callback, thisp );
                }
            }
        });
    
    return ret;
}();