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node_modules/core-js/modules/es6.reflect.construct.js
| 47 lines
| 1.9 KiB
| application/javascript
| JavascriptLexer
|
| r789 | // 26.1.2 Reflect.construct(target, argumentsList [, newTarget]) | |||
| var $export = require('./_export'); | ||||
| var create = require('./_object-create'); | ||||
| var aFunction = require('./_a-function'); | ||||
| var anObject = require('./_an-object'); | ||||
| var isObject = require('./_is-object'); | ||||
| var fails = require('./_fails'); | ||||
| var bind = require('./_bind'); | ||||
| var rConstruct = (require('./_global').Reflect || {}).construct; | ||||
| // MS Edge supports only 2 arguments and argumentsList argument is optional | ||||
| // FF Nightly sets third argument as `new.target`, but does not create `this` from it | ||||
| var NEW_TARGET_BUG = fails(function () { | ||||
| function F() { /* empty */ } | ||||
| return !(rConstruct(function () { /* empty */ }, [], F) instanceof F); | ||||
| }); | ||||
| var ARGS_BUG = !fails(function () { | ||||
| rConstruct(function () { /* empty */ }); | ||||
| }); | ||||
| $export($export.S + $export.F * (NEW_TARGET_BUG || ARGS_BUG), 'Reflect', { | ||||
| construct: function construct(Target, args /* , newTarget */) { | ||||
| aFunction(Target); | ||||
| anObject(args); | ||||
| var newTarget = arguments.length < 3 ? Target : aFunction(arguments[2]); | ||||
| if (ARGS_BUG && !NEW_TARGET_BUG) return rConstruct(Target, args, newTarget); | ||||
| if (Target == newTarget) { | ||||
| // w/o altered newTarget, optimization for 0-4 arguments | ||||
| switch (args.length) { | ||||
| case 0: return new Target(); | ||||
| case 1: return new Target(args[0]); | ||||
| case 2: return new Target(args[0], args[1]); | ||||
| case 3: return new Target(args[0], args[1], args[2]); | ||||
| case 4: return new Target(args[0], args[1], args[2], args[3]); | ||||
| } | ||||
| // w/o altered newTarget, lot of arguments case | ||||
| var $args = [null]; | ||||
| $args.push.apply($args, args); | ||||
| return new (bind.apply(Target, $args))(); | ||||
| } | ||||
| // with altered newTarget, not support built-in constructors | ||||
| var proto = newTarget.prototype; | ||||
| var instance = create(isObject(proto) ? proto : Object.prototype); | ||||
| var result = Function.apply.call(Target, instance, args); | ||||
| return isObject(result) ? result : instance; | ||||
| } | ||||
| }); | ||||