1/** Error message constants. */
2var FUNC_ERROR_TEXT = 'Expected a function';
3
4/**
5 * Creates a function that negates the result of the predicate `func`. The
6 * `func` predicate is invoked with the `this` binding and arguments of the
7 * created function.
8 *
9 * @static
10 * @memberOf _
11 * @since 3.0.0
12 * @category Function
13 * @param {Function} predicate The predicate to negate.
14 * @returns {Function} Returns the new negated function.
15 * @example
16 *
17 * function isEven(n) {
18 *   return n % 2 == 0;
19 * }
20 *
21 * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
22 * // => [1, 3, 5]
23 */
24function negate(predicate) {
25  if (typeof predicate != 'function') {
26    throw new TypeError(FUNC_ERROR_TEXT);
27  }
28  return function() {
29    var args = arguments;
30    switch (args.length) {
31      case 0: return !predicate.call(this);
32      case 1: return !predicate.call(this, args[0]);
33      case 2: return !predicate.call(this, args[0], args[1]);
34      case 3: return !predicate.call(this, args[0], args[1], args[2]);
35    }
36    return !predicate.apply(this, args);
37  };
38}
39
40module.exports = negate;
41