curryN.js•1.6 kB
var _arity = require('./internal/_arity');
var _curry1 = require('./internal/_curry1');
var _curry2 = require('./internal/_curry2');
var _curryN = require('./internal/_curryN');
/**
* Returns a curried equivalent of the provided function, with the specified
* arity. The curried function has two unusual capabilities. First, its
* arguments needn't be provided one at a time. If `g` is `R.curryN(3, f)`, the
* following are equivalent:
*
* - `g(1)(2)(3)`
* - `g(1)(2, 3)`
* - `g(1, 2)(3)`
* - `g(1, 2, 3)`
*
* Secondly, the special placeholder value `R.__` may be used to specify
* "gaps", allowing partial application of any combination of arguments,
* regardless of their positions. If `g` is as above and `_` is `R.__`, the
* following are equivalent:
*
* - `g(1, 2, 3)`
* - `g(_, 2, 3)(1)`
* - `g(_, _, 3)(1)(2)`
* - `g(_, _, 3)(1, 2)`
* - `g(_, 2)(1)(3)`
* - `g(_, 2)(1, 3)`
* - `g(_, 2)(_, 3)(1)`
*
* @func
* @memberOf R
* @since v0.5.0
* @category Function
* @sig Number -> (* -> a) -> (* -> a)
* @param {Number} length The arity for the returned function.
* @param {Function} fn The function to curry.
* @return {Function} A new, curried function.
* @see R.curry
* @example
*
* var sumArgs = (...args) => R.sum(args);
*
* var curriedAddFourNumbers = R.curryN(4, sumArgs);
* var f = curriedAddFourNumbers(1, 2);
* var g = f(3);
* g(4); //=> 10
*/
module.exports = _curry2(function curryN(length, fn) {
if (length === 1) {
return _curry1(fn);
}
return _arity(length, _curryN(length, [], fn));
});