From JavaScript: The Good Parts

goodparts.js

if (typeof Object.inherit === 'undefined') {
    Object.inherit = function(o) {
        var F = function() {};
        F.prototype = o;
        return new F();
    }
} else {
    throw {'name' : 'Method Duplication', 'message' : 'Object.create already defined'};
}

if (typeof Array.dim === 'undefined') {
    Array.dim = function(dimension, initial) {
        var a = [], i;
        for (i = 0; i < dimension; i+= 1) {
            a[i] = initial;
        }
        return a;
    }
} else {
    throw {'name' : 'Method Duplication', 'message' : 'Object.create already defined'};
}

if (typeof Function.prototype.method === 'undefined') {
    Function.prototype.method = function(name, func, override) {
        if (override || typeof this.prototype[name] === 'undefined') {
            this.prototype[name] = func;
        }
        return this;
    };
} else {
    throw {'name' : 'Method Duplication', 'message' : 'Function.prototype.method already defined'};
}

Object.method('superior', function(name) {
    var that = this;
    var method = that[name];
    return function() {
        return method.apply(that, arguments);
    };
});

Number.method('integer', function() {
    return Math[this < 0 ? 'ceil' : 'floor'](this);
});

String.method('trim', function() {
    return this.replace(/^\s+|\s+$/g, '');
});

Function.method('curry', function() {
    var slice = Array.prototype.slice;
    var args = slice.apply(arguments);
    var that = this;
    return function() {
        return that.apply(null, args.concat(slice.apply(arguments)));
    };
});

Array.method('reduce', function (f, value) {
    var i;
    for (i = 0; i < this.length; i++) {
        value = f(this[i], value);
    }
    return value;
});

if (typeof is_array === 'undefined') {
    is_array = function(value) {
        return value &&
            typeof value === 'object' &&
            typeof value.length === 'number' &&
            typeof value.splice === 'function' &&
            !(value.propertyIsEnumerable('length'));
    }
}