Currying implementation

index.js

function currying(func) {
  // how many args that func needs
  var totalArgs = func.length;

  var partial = function(args) {
    return function() {
      var newArgs = Array.prototype.slice.call(arguments, 0);
      return fn.apply(null, args.concat(newArgs));
    }
  }

  var fn = function() {
    var args = Array.prototype.slice.call(arguments, 0);

    // if still need more args
    if (totalArgs > args.length) {
      // recursive to get more args
      return partial(args);
    } else {
      return func.apply(null, args);
    }
  }

  return fn;
}

module.exports = currying;