nAry.js•2.1 kB
var _curry2 = require('./internal/_curry2');
/**
* Wraps a function of any arity (including nullary) in a function that accepts
* exactly `n` parameters. Any extraneous parameters will not be passed to the
* supplied function.
*
* @func
* @memberOf R
* @since v0.1.0
* @category Function
* @sig Number -> (* -> a) -> (* -> a)
* @param {Number} n The desired arity of the new function.
* @param {Function} fn The function to wrap.
* @return {Function} A new function wrapping `fn`. The new function is guaranteed to be of
* arity `n`.
* @example
*
* var takesTwoArgs = (a, b) => [a, b];
*
* takesTwoArgs.length; //=> 2
* takesTwoArgs(1, 2); //=> [1, 2]
*
* var takesOneArg = R.nAry(1, takesTwoArgs);
* takesOneArg.length; //=> 1
* // Only `n` arguments are passed to the wrapped function
* takesOneArg(1, 2); //=> [1, undefined]
*/
module.exports = _curry2(function nAry(n, fn) {
switch (n) {
case 0: return function() {return fn.call(this);};
case 1: return function(a0) {return fn.call(this, a0);};
case 2: return function(a0, a1) {return fn.call(this, a0, a1);};
case 3: return function(a0, a1, a2) {return fn.call(this, a0, a1, a2);};
case 4: return function(a0, a1, a2, a3) {return fn.call(this, a0, a1, a2, a3);};
case 5: return function(a0, a1, a2, a3, a4) {return fn.call(this, a0, a1, a2, a3, a4);};
case 6: return function(a0, a1, a2, a3, a4, a5) {return fn.call(this, a0, a1, a2, a3, a4, a5);};
case 7: return function(a0, a1, a2, a3, a4, a5, a6) {return fn.call(this, a0, a1, a2, a3, a4, a5, a6);};
case 8: return function(a0, a1, a2, a3, a4, a5, a6, a7) {return fn.call(this, a0, a1, a2, a3, a4, a5, a6, a7);};
case 9: return function(a0, a1, a2, a3, a4, a5, a6, a7, a8) {return fn.call(this, a0, a1, a2, a3, a4, a5, a6, a7, a8);};
case 10: return function(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) {return fn.call(this, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9);};
default: throw new Error('First argument to nAry must be a non-negative integer no greater than ten');
}
});