title: uncurry tags: function,intermediate

Uncurries a function up to depth n.

Return a variadic function. Use Array.prototype.reduce() on the provided arguments to call each subsequent curry level of the function. If the length of the provided arguments is less than n throw an error. Otherwise, call fn with the proper amount of arguments, using Array.prototype.slice(0, n). Omit the second argument, n, to uncurry up to depth 1.

const uncurry = (fn, n = 1) => (...args) => {
  const next = (acc) => (args) => args.reduce((x, y) => x(y), acc);
  if (n > args.length) throw new RangeError("Arguments too few!");
  return next(fn)(args.slice(0, n));
};

const add = (x) => (y) => (z) => x + y + z;
const uncurriedAdd = uncurry(add, 3);
uncurriedAdd(1, 2, 3); // 6