import _curry1 from './internal/_curry1.js';

import nAry from './nAry.js';

/**

* Wraps a function of any arity (including nullary) in a function that accepts

* exactly 2 parameters. Any extraneous parameters will not be passed to the

* supplied function.

*

* @func

* @memberOf R

* @since v0.2.0

* @category Function

* @sig (a -> b -> c -> ... -> z) -> ((a, b) -> z)

* @param {Function} fn The function to wrap.

* @return {Function} A new function wrapping `fn`. The new function is guaranteed to be of

* arity 2.

* @see R.nAry, R.unary

* @example

*

* const takesThreeArgs = function(a, b, c) {

* return [a, b, c];

* };

* takesThreeArgs.length; //=> 3

* takesThreeArgs(1, 2, 3); //=> [1, 2, 3]

*

* const takesTwoArgs = R.binary(takesThreeArgs);

* takesTwoArgs.length; //=> 2

* // Only 2 arguments are passed to the wrapped function

* takesTwoArgs(1, 2, 3); //=> [1, 2, undefined]

* @symb R.binary(f)(a, b, c) = f(a, b)

*/

var binary = _curry1(function binary(fn) {

return nAry(2, fn);

});

export default binary;