lodash.js 5.6 KB
define(['../internal/LazyWrapper', '../internal/LodashWrapper', '../internal/baseLodash', '../lang/isArray', '../internal/isObjectLike', '../internal/wrapperClone'], function(LazyWrapper, LodashWrapper, baseLodash, isArray, isObjectLike, wrapperClone) {

  /** Used for native method references. */
  var objectProto = Object.prototype;

  /** Used to check objects for own properties. */
  var hasOwnProperty = objectProto.hasOwnProperty;

  /**
   * Creates a `lodash` object which wraps `value` to enable implicit chaining.
   * Methods that operate on and return arrays, collections, and functions can
   * be chained together. Methods that retrieve a single value or may return a
   * primitive value will automatically end the chain returning the unwrapped
   * value. Explicit chaining may be enabled using `_.chain`. The execution of
   * chained methods is lazy, that is, execution is deferred until `_#value`
   * is implicitly or explicitly called.
   *
   * Lazy evaluation allows several methods to support shortcut fusion. Shortcut
   * fusion is an optimization strategy which merge iteratee calls; this can help
   * to avoid the creation of intermediate data structures and greatly reduce the
   * number of iteratee executions.
   *
   * Chaining is supported in custom builds as long as the `_#value` method is
   * directly or indirectly included in the build.
   *
   * In addition to lodash methods, wrappers have `Array` and `String` methods.
   *
   * The wrapper `Array` methods are:
   * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`,
   * `splice`, and `unshift`
   *
   * The wrapper `String` methods are:
   * `replace` and `split`
   *
   * The wrapper methods that support shortcut fusion are:
   * `compact`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`,
   * `first`, `initial`, `last`, `map`, `pluck`, `reject`, `rest`, `reverse`,
   * `slice`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `toArray`,
   * and `where`
   *
   * The chainable wrapper methods are:
   * `after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`,
   * `callback`, `chain`, `chunk`, `commit`, `compact`, `concat`, `constant`,
   * `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`,
   * `defer`, `delay`, `difference`, `drop`, `dropRight`, `dropRightWhile`,
   * `dropWhile`, `fill`, `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`,
   * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`,
   * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`,
   * `invoke`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`,
   * `matchesProperty`, `memoize`, `merge`, `method`, `methodOf`, `mixin`,
   * `modArgs`, `negate`, `omit`, `once`, `pairs`, `partial`, `partialRight`,
   * `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`,
   * `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `restParam`,
   * `reverse`, `set`, `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`,
   * `sortByOrder`, `splice`, `spread`, `take`, `takeRight`, `takeRightWhile`,
   * `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`,
   * `transform`, `union`, `uniq`, `unshift`, `unzip`, `unzipWith`, `values`,
   * `valuesIn`, `where`, `without`, `wrap`, `xor`, `zip`, `zipObject`, `zipWith`
   *
   * The wrapper methods that are **not** chainable by default are:
   * `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clone`, `cloneDeep`,
   * `deburr`, `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`,
   * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`,
   * `floor`, `get`, `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`,
   * `inRange`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`,
   * `isEmpty`, `isEqual`, `isError`, `isFinite` `isFunction`, `isMatch`,
   * `isNative`, `isNaN`, `isNull`, `isNumber`, `isObject`, `isPlainObject`,
   * `isRegExp`, `isString`, `isUndefined`, `isTypedArray`, `join`, `kebabCase`,
   * `last`, `lastIndexOf`, `lt`, `lte`, `max`, `min`, `noConflict`, `noop`,
   * `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, `random`, `reduce`,
   * `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `shift`, `size`,
   * `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, `startCase`,
   * `startsWith`, `sum`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`,
   * `unescape`, `uniqueId`, `value`, and `words`
   *
   * The wrapper method `sample` will return a wrapped value when `n` is provided,
   * otherwise an unwrapped value is returned.
   *
   * @name _
   * @constructor
   * @category Chain
   * @param {*} value The value to wrap in a `lodash` instance.
   * @returns {Object} Returns the new `lodash` wrapper instance.
   * @example
   *
   * var wrapped = _([1, 2, 3]);
   *
   * // returns an unwrapped value
   * wrapped.reduce(function(total, n) {
   *   return total + n;
   * });
   * // => 6
   *
   * // returns a wrapped value
   * var squares = wrapped.map(function(n) {
   *   return n * n;
   * });
   *
   * _.isArray(squares);
   * // => false
   *
   * _.isArray(squares.value());
   * // => true
   */
  function lodash(value) {
    if (isObjectLike(value) && !isArray(value) && !(value instanceof LazyWrapper)) {
      if (value instanceof LodashWrapper) {
        return value;
      }
      if (hasOwnProperty.call(value, '__chain__') && hasOwnProperty.call(value, '__wrapped__')) {
        return wrapperClone(value);
      }
    }
    return new LodashWrapper(value);
  }

  // Ensure wrappers are instances of `baseLodash`.
  lodash.prototype = baseLodash.prototype;

  return lodash;
});