jon
9/24/2014 - 8:46 AM

## Simple way to recursively curry javascript functions http://jsfiddle.net/amatiasq/osrsomq0/

Simple way to recursively curry javascript functions http://jsfiddle.net/amatiasq/osrsomq0/

``````var log = console.log.bind(console);

// empty calls are ignored
curry(log, 1) ()()()()(1); // Logs: 1

// extra args are passed
curry(log, 1) (1, 2, 3, 4); // Logs: 1 2 3 4

// recursive currification
curry(log, 5) (1)(2)(3)(4)(5); // 1 2 3 4 5

// works with all combination
curry(log, 4) (1, 2, 3, 4); // Logs: 1 2 3 4
curry(log, 4) (1, 2, 3)(4); // Logs: 1 2 3 4
curry(log, 4) (1, 2)(3, 4); // Logs: 1 2 3 4
curry(log, 4) (1)(2, 3, 4); // Logs: 1 2 3 4
curry(log, 4) (1, 2)(3)(4); // Logs: 1 2 3 4
curry(log, 4) (1)(2)(3, 4); // Logs: 1 2 3 4
curry(log, 4) (1)(2, 3)(4); // Logs: 1 2 3 4
curry(log, 4) (1)(2)(3)(4); // Logs: 1 2 3 4

// function is not invoked until argument lenght is reached
console.log(curry(log, 4) (1)(2)(3)); // returns function currified() { ... }

// when argument length is reached function is invoked and its result is returned
try {
curry(log, 4) (1)(2)(3)(4)(5); // logs 1 2 3 4 & throws undefined is not a function
} catch(err) {
console.log(err);
}

function sum(a, b) {
return a + b;
}

// argument length detected automatically
console.log(curry(sum)(1)(2));``````
``````/**
* @param {Function} fn Function to curry.
* @param {Number} lenght The arguments required to invoke the function. Optional. By default is fn.length
* @returns {Function} The currified function.
*/
function curry(fn, length) {
length = length || fn.length;
return function currified() {
var args = [].slice.call(arguments);

if (args.length === 0)
return currified;

if (args.length >= length)
return fn.apply(this, args);

var child = fn.bind.apply(fn, [this].concat(args));
return curry(child, length - args.length);
};
}``````