dropWhile.js

import _curry2 from './internal/_curry2.js';
import _dispatchable from './internal/_dispatchable.js';
import _xdropWhile from './internal/_xdropWhile.js';
import slice from './slice.js';


/**
 * Returns a new list excluding the leading elements of a given list which
 * satisfy the supplied predicate function. It passes each value to the supplied
 * predicate function, skipping elements while the predicate function returns
 * `true`. The predicate function is applied to one argument: *(value)*.
 *
 * Dispatches to the `dropWhile` method of the second argument, if present.
 *
 * Acts as a transducer if a transformer is given in list position.
 *
 * @func
 * @memberOf R
 * @since v0.9.0
 * @category List
 * @sig (a -> Boolean) -> [a] -> [a]
 * @sig (a -> Boolean) -> String -> String
 * @param {Function} fn The function called per iteration.
 * @param {Array} xs The collection to iterate over.
 * @return {Array} A new array.
 * @see R.takeWhile, R.transduce, R.addIndex
 * @example
 *
 *      const lteTwo = x => x <= 2;
 *
 *      R.dropWhile(lteTwo, [1, 2, 3, 4, 3, 2, 1]); //=> [3, 4, 3, 2, 1]
 *
 *      R.dropWhile(x => x !== 'd' , 'Ramda'); //=> 'da'
 */
var dropWhile = _curry2(_dispatchable(['dropWhile'], _xdropWhile, function dropWhile(pred, xs) {
  var idx = 0;
  var len = xs.length;
  while (idx < len && pred(xs[idx])) {
    idx += 1;
  }
  return slice(idx, Infinity, xs);
}));
export default dropWhile;