array.js

// Add convienent array methods if non-existant
if (!Array.forEach) {
    Array.forEach = function(array, fun, thisp) {
        var len = array.length;
        for ( var i = 0; i < len; i++) {
            if (i in array) {
                fun.call(thisp, array[i], i, array);
            }
        }
    };
}
if (!Array.map) {
    Array.map = function(array, fun, thisp) {
        var len = array.length;
        var res = [];
        for ( var i = 0; i < len; i++) {
            if (i in array) {
                res[i] = fun.call(thisp, array[i], i, array);
            }
        }
        return res;
    };
}
if (!Array.filter) {
    Array.filter = function(array, fun, thisp) {
        var len = array.length;
        var res = [];
        for ( var i = 0; i < len; i++) {
            if (i in array) {
                var val = array[i];
                if (fun.call(thisp, val, i, array)) {
                    res.push(val);
                }
            }
        }
        return res;
    };
}

if (!Array.erase) {
    Array.erase = function(array, object) {
        var erased = false;
        var idx = -1;
        while( (idx = array.indexOf(object) ) != -1){
            array.splice(idx, 1);
            erased = true;
        }
        return erased;
    };
}

if (!Array.set) {
    Array.set = function(array, offset, value) {
        for (var i=0; i < value.length; i++)
            array[offset+i] = value[i];
    };
}

if (!Array.isArray) {
    Array.isArray = function(arg) {
        return Object.prototype.toString.call(arg) == '[object Array]';
    };
}