| /** Error message constants. */ |
| var FUNC_ERROR_TEXT = 'Expected a function'; |
| |
| /** |
| * Creates a function that negates the result of the predicate `func`. The |
| * `func` predicate is invoked with the `this` binding and arguments of the |
| * created function. |
| * |
| * @static |
| * @memberOf _ |
| * @since 3.0.0 |
| * @category Function |
| * @param {Function} predicate The predicate to negate. |
| * @returns {Function} Returns the new negated function. |
| * @example |
| * |
| * function isEven(n) { |
| * return n % 2 == 0; |
| * } |
| * |
| * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven)); |
| * // => [1, 3, 5] |
| */ |
| function negate(predicate) { |
| if (typeof predicate != 'function') { |
| throw new TypeError(FUNC_ERROR_TEXT); |
| } |
| return function() { |
| var args = arguments; |
| switch (args.length) { |
| case 0: return !predicate.call(this); |
| case 1: return !predicate.call(this, args[0]); |
| case 2: return !predicate.call(this, args[0], args[1]); |
| case 3: return !predicate.call(this, args[0], args[1], args[2]); |
| } |
| return !predicate.apply(this, args); |
| }; |
| } |
| |
| module.exports = negate; |