6da415b41c0bae9c96fd40df253df2de7d965f4c.svn-base 1.83 KB
var arrayEvery = require('./_arrayEvery'),
    baseEvery = require('./_baseEvery'),
    baseIteratee = require('./_baseIteratee'),
    isArray = require('./isArray'),
    isIterateeCall = require('./_isIterateeCall');

/**
 * Checks if `predicate` returns truthy for **all** elements of `collection`.
 * Iteration is stopped once `predicate` returns falsey. The predicate is
 * invoked with three arguments: (value, index|key, collection).
 *
 * **Note:** This method returns `true` for
 * [empty collections](https://en.wikipedia.org/wiki/Empty_set) because
 * [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of
 * elements of empty collections.
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @category Collection
 * @param {Array|Object} collection The collection to iterate over.
 * @param {Function} [predicate=_.identity] The function invoked per iteration.
 * @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.
 * @returns {boolean} Returns `true` if all elements pass the predicate check,
 *  else `false`.
 * @example
 *
 * _.every([true, 1, null, 'yes'], Boolean);
 * // => false
 *
 * var users = [
 *   { 'user': 'barney', 'age': 36, 'active': false },
 *   { 'user': 'fred',   'age': 40, 'active': false }
 * ];
 *
 * // The `_.matches` iteratee shorthand.
 * _.every(users, { 'user': 'barney', 'active': false });
 * // => false
 *
 * // The `_.matchesProperty` iteratee shorthand.
 * _.every(users, ['active', false]);
 * // => true
 *
 * // The `_.property` iteratee shorthand.
 * _.every(users, 'active');
 * // => false
 */
function every(collection, predicate, guard) {
  var func = isArray(collection) ? arrayEvery : baseEvery;
  if (guard && isIterateeCall(collection, predicate, guard)) {
    predicate = undefined;
  }
  return func(collection, baseIteratee(predicate, 3));
}

module.exports = every;