Function createWrap

lodash.js:5581–5634

* 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 wrap. * @param {number} bitmask The bitmask flags. * 1 - `_.bind`

(func, bitmask, thisArg, partials, holders, argPos, ary, arity)

     * @returns {Function} Returns the new wrapped function.
     */
    function createWrap(func, bitmask, thisArg, partials, holders, argPos, ary, arity) {
      var isBindKey = bitmask & WRAP_BIND_KEY_FLAG;
      if (!isBindKey && typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      var length = partials ? partials.length : 0;
      if (!length) {
        bitmask &= ~(WRAP_PARTIAL_FLAG | WRAP_PARTIAL_RIGHT_FLAG);
        partials = holders = undefined;
      }
      ary = ary === undefined ? ary : nativeMax(toInteger(ary), 0);
      arity = arity === undefined ? arity : toInteger(arity);
      length -= holders ? holders.length : 0;

      if (bitmask & WRAP_PARTIAL_RIGHT_FLAG) {
        var partialsRight = partials,
            holdersRight = holders;

        partials = holders = undefined;
      }
      var data = isBindKey ? undefined : getData(func);

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

      if (data) {
        mergeData(newData, data);
      }
      func = newData[0];
      bitmask = newData[1];
      thisArg = newData[2];
      partials = newData[3];
      holders = newData[4];
      arity = newData[9] = newData[9] === undefined
        ? (isBindKey ? 0 : func.length)
        : nativeMax(newData[9] - length, 0);

      if (!arity && bitmask & (WRAP_CURRY_FLAG | WRAP_CURRY_RIGHT_FLAG)) {
        bitmask &= ~(WRAP_CURRY_FLAG | WRAP_CURRY_RIGHT_FLAG);
      }
      if (!bitmask || bitmask == WRAP_BIND_FLAG) {
        var result = createBind(func, bitmask, thisArg);
      } else if (bitmask == WRAP_CURRY_FLAG || bitmask == WRAP_CURRY_RIGHT_FLAG) {
        result = createCurry(func, bitmask, arity);
      } else if ((bitmask == WRAP_PARTIAL_FLAG || bitmask == (WRAP_BIND_FLAG | WRAP_PARTIAL_FLAG)) && !holders.length) {
        result = createPartial(func, bitmask, thisArg, partials);
      } else {
        result = createHybrid.apply(undefined, newData);
      }
      var setter = data ? baseSetData : setData;
      return setWrapToString(setter(result, newData), func, bitmask);
    }

    /**
     * Used by `_.defaults` to customize its `_.assignIn` use to assign properties