lodash/lodash._createwrapper/index.js

/**
 * lodash 3.0.2 (Custom Build) <https://lodash.com/>
 * Build: `lodash modern modularize exports="npm" -o ./`
 * Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.2 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var arrayCopy = require('lodash._arraycopy'),
    baseCreate = require('lodash._basecreate'),
    replaceHolders = require('lodash._replaceholders');

/** Used to compose bitmasks for wrapper metadata. */
var BIND_FLAG = 1,
    BIND_KEY_FLAG = 2,
    CURRY_BOUND_FLAG = 4,
    CURRY_FLAG = 8,
    CURRY_RIGHT_FLAG = 16,
    PARTIAL_FLAG = 32,
    PARTIAL_RIGHT_FLAG = 64,
    ARY_FLAG = 256;

/** Used as the `TypeError` message for "Functions" methods. */
var FUNC_ERROR_TEXT = 'Expected a function';

/* Native method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max,
    nativeMin = Math.min;

/**
 * Used as the maximum length of an array-like value.
 * See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
 * for more details.
 */
var MAX_SAFE_INTEGER = Math.pow(2, 53) - 1;

/**
 * Creates an array that is the composition of partially applied arguments,
 * placeholders, and provided arguments into a single array of arguments.
 *
 * @private
 * @param {Array|Object} args The provided arguments.
 * @param {Array} partials The arguments to prepend to those provided.
 * @param {Array} holders The `partials` placeholder indexes.
 * @returns {Array} Returns the new array of composed arguments.
 */
function composeArgs(args, partials, holders) {
  var holdersLength = holders.length,
      argsIndex = -1,
      argsLength = nativeMax(args.length - holdersLength, 0),
      leftIndex = -1,
      leftLength = partials.length,
      result = Array(argsLength + leftLength);

  while (++leftIndex < leftLength) {
    result[leftIndex] = partials[leftIndex];
  }
  while (++argsIndex < holdersLength) {
    result[holders[argsIndex]] = args[argsIndex];
  }
  while (argsLength--) {
    result[leftIndex++] = args[argsIndex++];
  }
  return result;
}

/**
 * This function is like `composeArgs` except that the arguments composition
 * is tailored for `_.partialRight`.
 *
 * @private
 * @param {Array|Object} args The provided arguments.
 * @param {Array} partials The arguments to append to those provided.
 * @param {Array} holders The `partials` placeholder indexes.
 * @returns {Array} Returns the new array of composed arguments.
 */
function composeArgsRight(args, partials, holders) {
  var holdersIndex = -1,
      holdersLength = holders.length,
      argsIndex = -1,
      argsLength = nativeMax(args.length - holdersLength, 0),
      rightIndex = -1,
      rightLength = partials.length,
      result = Array(argsLength + rightLength);

  while (++argsIndex < argsLength) {
    result[argsIndex] = args[argsIndex];
  }
  var pad = argsIndex;
  while (++rightIndex < rightLength) {
    result[pad + rightIndex] = partials[rightIndex];
  }
  while (++holdersIndex < holdersLength) {
    result[pad + holders[holdersIndex]] = args[argsIndex++];
  }
  return result;
}

/**
 * Creates a function that wraps `func` and invokes it with the `this`
 * binding of `thisArg`.
 *
 * @private
 * @param {Function} func The function to bind.
 * @param {*} [thisArg] The `this` binding of `func`.
 * @returns {Function} Returns the new bound function.
 */
function createBindWrapper(func, thisArg) {
  var Ctor = createCtorWrapper(func);

  function wrapper() {
    var fn = (this && this !== global && this instanceof wrapper) ? Ctor : func;
    return fn.apply(thisArg, arguments);
  }
  return wrapper;
}

/**
 * Creates a function that produces an instance of `Ctor` regardless of
 * whether it was invoked as part of a `new` expression or by `call` or `apply`.
 *
 * @private
 * @param {Function} Ctor The constructor to wrap.
 * @returns {Function} Returns the new wrapped function.
 */
function createCtorWrapper(Ctor) {
  return function() {
    var thisBinding = baseCreate(Ctor.prototype),
        result = Ctor.apply(thisBinding, arguments);

    // Mimic the constructor's `return` behavior.
    // See https://es5.github.io/#x13.2.2 for more details.
    return isObject(result) ? result : thisBinding;
  };
}

/**
 * Creates a function that wraps `func` and invokes it with optional `this`
 * binding of, partial application, and currying.
 *
 * @private
 * @param {Function|string} func The function or method name to reference.
 * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details.
 * @param {*} [thisArg] The `this` binding of `func`.
 * @param {Array} [partials] The arguments to prepend to those provided to the new function.
 * @param {Array} [holders] The `partials` placeholder indexes.
 * @param {Array} [partialsRight] The arguments to append to those provided to the new function.
 * @param {Array} [holdersRight] The `partialsRight` placeholder indexes.
 * @param {Array} [argPos] The argument positions of the new function.
 * @param {number} [ary] The arity cap of `func`.
 * @param {number} [arity] The arity of `func`.
 * @returns {Function} Returns the new wrapped function.
 */
function createHybridWrapper(func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity) {
  var isAry = bitmask & ARY_FLAG,
      isBind = bitmask & BIND_FLAG,
      isBindKey = bitmask & BIND_KEY_FLAG,
      isCurry = bitmask & CURRY_FLAG,
      isCurryBound = bitmask & CURRY_BOUND_FLAG,
      isCurryRight = bitmask & CURRY_RIGHT_FLAG;

  var Ctor = !isBindKey && createCtorWrapper(func),
      key = func;

  function wrapper() {
    // Avoid `arguments` object use disqualifying optimizations by
    // converting it to an array before providing it to other functions.
    var length = arguments.length,
        index = length,
        args = Array(length);

    while (index--) {
      args[index] = arguments[index];
    }
    if (partials) {
      args = composeArgs(args, partials, holders);
    }
    if (partialsRight) {
      args = composeArgsRight(args, partialsRight, holdersRight);
    }
    if (isCurry || isCurryRight) {
      var placeholder = wrapper.placeholder,
          argsHolders = replaceHolders(args, placeholder);

      length -= argsHolders.length;
      if (length < arity) {
        var newArgPos = argPos ? arrayCopy(argPos) : null,
            newArity = nativeMax(arity - length, 0),
            newsHolders = isCurry ? argsHolders : null,
            newHoldersRight = isCurry ? null : argsHolders,
            newPartials = isCurry ? args : null,
            newPartialsRight = isCurry ? null : args;

        bitmask |= (isCurry ? PARTIAL_FLAG : PARTIAL_RIGHT_FLAG);
        bitmask &= ~(isCurry ? PARTIAL_RIGHT_FLAG : PARTIAL_FLAG);

        if (!isCurryBound) {
          bitmask &= ~(BIND_FLAG | BIND_KEY_FLAG);
        }
        var result = createHybridWrapper(func, bitmask, thisArg, newPartials, newsHolders, newPartialsRight, newHoldersRight, newArgPos, ary, newArity);
        result.placeholder = placeholder;
        return result;
      }
    }
    var thisBinding = isBind ? thisArg : this;
    if (isBindKey) {
      func = thisBinding[key];
    }
    if (argPos) {
      args = reorder(args, argPos);
    }
    if (isAry && ary < args.length) {
      args.length = ary;
    }
    var fn = (this && this !== global && this instanceof wrapper) ? (Ctor || createCtorWrapper(func)) : func;
    return fn.apply(thisBinding, args);
  }
  return wrapper;
}

/**
 * Creates a function that wraps `func` and invokes it with the optional `this`
 * binding of `thisArg` and the `partials` prepended to those provided to
 * the wrapper.
 *
 * @private
 * @param {Function} func The function to partially apply arguments to.
 * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details.
 * @param {*} thisArg The `this` binding of `func`.
 * @param {Array} partials The arguments to prepend to those provided to the new function.
 * @returns {Function} Returns the new bound function.
 */
function createPartialWrapper(func, bitmask, thisArg, partials) {
  var isBind = bitmask & BIND_FLAG,
      Ctor = createCtorWrapper(func);

  function wrapper() {
    // Avoid `arguments` object use disqualifying optimizations by
    // converting it to an array before providing it `func`.
    var argsIndex = -1,
        argsLength = arguments.length,
        leftIndex = -1,
        leftLength = partials.length,
        args = Array(argsLength + leftLength);

    while (++leftIndex < leftLength) {
      args[leftIndex] = partials[leftIndex];
    }
    while (argsLength--) {
      args[leftIndex++] = arguments[++argsIndex];
    }
    var fn = (this && this !== global && this instanceof wrapper) ? Ctor : func;
    return fn.apply(isBind ? thisArg : this, args);
  }
  return wrapper;
}

/**
 * Creates a function that either curries or invokes `func` with optional
 * `this` binding and partially applied arguments.
 *
 * @private
 * @param {Function|string} func The function or method name to reference.
 * @param {number} bitmask The bitmask of flags.
 *  The bitmask may be composed of the following flags:
 *     1 - `_.bind`
 *     2 - `_.bindKey`
 *     4 - `_.curry` or `_.curryRight` of a bound function
 *     8 - `_.curry`
 *    16 - `_.curryRight`
 *    32 - `_.partial`
 *    64 - `_.partialRight`
 *   128 - `_.rearg`
 *   256 - `_.ary`
 * @param {*} [thisArg] The `this` binding of `func`.
 * @param {Array} [partials] The arguments to be partially applied.
 * @param {Array} [holders] The `partials` placeholder indexes.
 * @param {Array} [argPos] The argument positions of the new function.
 * @param {number} [ary] The arity cap of `func`.
 * @param {number} [arity] The arity of `func`.
 * @returns {Function} Returns the new wrapped function.
 */
function createWrapper(func, bitmask, thisArg, partials, holders, argPos, ary, arity) {
  var isBindKey = bitmask & BIND_KEY_FLAG;
  if (!isBindKey && typeof func != 'function') {
    throw new TypeError(FUNC_ERROR_TEXT);
  }
  var length = partials ? partials.length : 0;
  if (!length) {
    bitmask &= ~(PARTIAL_FLAG | PARTIAL_RIGHT_FLAG);
    partials = holders = null;
  }
  length -= (holders ? holders.length : 0);
  if (bitmask & PARTIAL_RIGHT_FLAG) {
    var partialsRight = partials,
        holdersRight = holders;

    partials = holders = null;
  }
  var newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity];

  newData[9] = arity == null
    ? (isBindKey ? 0 : func.length)
    : (nativeMax(arity - length, 0) || 0);

  if (bitmask == BIND_FLAG) {
    var result = createBindWrapper(newData[0], newData[2]);
  } else if ((bitmask == PARTIAL_FLAG || bitmask == (BIND_FLAG | PARTIAL_FLAG)) && !newData[4].length) {
    result = createPartialWrapper.apply(undefined, newData);
  } else {
    result = createHybridWrapper.apply(undefined, newData);
  }
  return result;
}

/**
 * Checks if `value` is a valid array-like index.
 *
 * @private
 * @param {*} value The value to check.
 * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
 * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
 */
function isIndex(value, length) {
  value = +value;
  length = length == null ? MAX_SAFE_INTEGER : length;
  return value > -1 && value % 1 == 0 && value < length;
}

/**
 * Reorder `array` according to the specified indexes where the element at
 * the first index is assigned as the first element, the element at
 * the second index is assigned as the second element, and so on.
 *
 * @private
 * @param {Array} array The array to reorder.
 * @param {Array} indexes The arranged array indexes.
 * @returns {Array} Returns `array`.
 */
function reorder(array, indexes) {
  var arrLength = array.length,
      length = nativeMin(indexes.length, arrLength),
      oldArray = arrayCopy(array);

  while (length--) {
    var index = indexes[length];
    array[length] = isIndex(index, arrLength) ? oldArray[index] : undefined;
  }
  return array;
}

/**
 * Checks if `value` is the language type of `Object`.
 * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * **Note:** See the [ES5 spec](https://es5.github.io/#x8) for more details.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an object, else `false`.
 * @example
 *
 * _.isObject({});
 * // => true
 *
 * _.isObject([1, 2, 3]);
 * // => true
 *
 * _.isObject(1);
 * // => false
 */
function isObject(value) {
  // Avoid a V8 JIT bug in Chrome 19-20.
  // See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
  var type = typeof value;
  return type == 'function' || (value && type == 'object') || false;
}

module.exports = createWrapper;