44 lines
1.3 KiB
JavaScript
44 lines
1.3 KiB
JavaScript
var apply = require('./_apply'),
|
|
createCtor = require('./_createCtor'),
|
|
root = require('./_root');
|
|
|
|
/** Used to compose bitmasks for function metadata. */
|
|
var WRAP_BIND_FLAG = 1;
|
|
|
|
/**
|
|
* Creates a function that wraps `func` to invoke it with the `this` binding
|
|
* of `thisArg` and `partials` prepended to the arguments it receives.
|
|
*
|
|
* @private
|
|
* @param {Function} func The function to wrap.
|
|
* @param {number} bitmask The bitmask flags. See `createWrap` 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 wrapped function.
|
|
*/
|
|
function createPartial(func, bitmask, thisArg, partials) {
|
|
var isBind = bitmask & WRAP_BIND_FLAG,
|
|
Ctor = createCtor(func);
|
|
|
|
function wrapper() {
|
|
var argsIndex = -1,
|
|
argsLength = arguments.length,
|
|
leftIndex = -1,
|
|
leftLength = partials.length,
|
|
args = Array(leftLength + argsLength),
|
|
fn = (this && this !== root && this instanceof wrapper) ? Ctor : func;
|
|
|
|
while (++leftIndex < leftLength) {
|
|
args[leftIndex] = partials[leftIndex];
|
|
}
|
|
while (argsLength--) {
|
|
args[leftIndex++] = arguments[++argsIndex];
|
|
}
|
|
return apply(fn, isBind ? thisArg : this, args);
|
|
}
|
|
return wrapper;
|
|
}
|
|
|
|
module.exports = createPartial;
|