createWrapper.js
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define(['./baseSetData', './createBindWrapper', './createHybridWrapper', './createPartialWrapper', './getData', './mergeData', './setData'], function(baseSetData, createBindWrapper, createHybridWrapper, createPartialWrapper, getData, mergeData, setData) {
/** Used as a safe reference for `undefined` in pre-ES5 environments. */
var undefined;
/** Used to compose bitmasks for wrapper metadata. */
var BIND_FLAG = 1,
BIND_KEY_FLAG = 2,
PARTIAL_FLAG = 32,
PARTIAL_RIGHT_FLAG = 64;
/** 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;
/**
* 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 = undefined;
}
length -= (holders ? holders.length : 0);
if (bitmask & PARTIAL_RIGHT_FLAG) {
var partialsRight = partials,
holdersRight = holders;
partials = holders = undefined;
}
var data = isBindKey ? undefined : getData(func),
newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity];
if (data) {
mergeData(newData, data);
bitmask = newData[1];
arity = newData[9];
}
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);
}
var setter = data ? baseSetData : setData;
return setter(result, newData);
}
return createWrapper;
});