mew.js

(function ()
{
    function partial(fun)
    {
        var _slice = [].slice,
            args = _slice.call(arguments);
        args.shift();
        return function ()
        {
            return fun.apply(this, args.concat(_slice.call(arguments)));
        };
    }
    
    var expr = function (n)
    {
        var utilities = {
            "+": function (a, b) { return a + b },
            "-": function (a, b) { return a - b },
            "*": function (a, b) { return a * b },
            "/": function (a, b) { return a / b }};
        
        var _n = n,
            _f = function () {};
        
        return function outer(op)
        {
            if (op === "=")  return _n;
            
            _f = partial(utilities[op], _n);
            return function (m)
            {
                _n = _f(m);
                return outer;
            }
        };
    };
    
    console.log( expr(4)("+")(3)("*")(2)("-")(1)("=") ); // 13
})();