takeLastWhile.js•1.01 kB
var _curry2 = require('./internal/_curry2');
var _slice = require('./internal/_slice');
/**
* Returns a new list containing the last `n` elements of a given list, passing
* each value to the supplied predicate function, and terminating when the
* predicate function returns `false`. Excludes the element that caused the
* predicate function to fail. The predicate function is passed one argument:
* *(value)*.
*
* @func
* @memberOf R
* @since v0.16.0
* @category List
* @sig (a -> Boolean) -> [a] -> [a]
* @param {Function} fn The function called per iteration.
* @param {Array} list The collection to iterate over.
* @return {Array} A new array.
* @see R.dropLastWhile, R.addIndex
* @example
*
* var isNotOne = x => x !== 1;
*
* R.takeLastWhile(isNotOne, [1, 2, 3, 4]); //=> [2, 3, 4]
*/
module.exports = _curry2(function takeLastWhile(fn, list) {
var idx = list.length - 1;
while (idx >= 0 && fn(list[idx])) {
idx -= 1;
}
return _slice(list, idx + 1, Infinity);
});