composeArgs.js 1.17 KB
define([], function() {

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

  /**
   * 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(leftLength + argsLength);

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

  return composeArgs;
});