ary.js
1.04 KB
var createWrapper = require('../internal/createWrapper'),
isIterateeCall = require('../internal/isIterateeCall');
/** Used to compose bitmasks for wrapper metadata. */
var ARY_FLAG = 128;
/* Native method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max;
/**
* Creates a function that accepts up to `n` arguments ignoring any
* additional arguments.
*
* @static
* @memberOf _
* @category Function
* @param {Function} func The function to cap arguments for.
* @param {number} [n=func.length] The arity cap.
* @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
* @returns {Function} Returns the new function.
* @example
*
* _.map(['6', '8', '10'], _.ary(parseInt, 1));
* // => [6, 8, 10]
*/
function ary(func, n, guard) {
if (guard && isIterateeCall(func, n, guard)) {
n = undefined;
}
n = (func && n == null) ? func.length : nativeMax(+n || 0, 0);
return createWrapper(func, ARY_FLAG, undefined, undefined, undefined, undefined, n);
}
module.exports = ary;