-
Notifications
You must be signed in to change notification settings - Fork 34
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
make @@toStringTag and constructor prototype properties funky accessors #287
Changes from 1 commit
e298671
f481720
7d48c43
d741076
File filter
Filter by extension
Conversations
Jump to
Diff view
Diff view
There are no files selected for viewing
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -289,7 +289,35 @@ <h1>Iterator.prototype</h1> | |
|
||
<emu-clause id="sec-iteratorprototype.constructor"> | ||
<h1>Iterator.prototype.constructor</h1> | ||
<p>The initial value of %Iterator.prototype%.constructor is %Iterator%.</p> | ||
<p>`Iterator.prototype.constructor` is an accessor property with attributes { [[Enumerable]]: *false*, [[Configurable]]: *true* }. The [[Get]] and [[Set]] attributes are defined as follows:</p> | ||
|
||
<emu-clause id="sec-get-iteratorprototype-constructor"> | ||
<h1>get Iterator.prototype.constructor</h1> | ||
<p>The value of the [[Get]] attribute is a built-in function that requires no arguments. It performs the following steps when called:</p> | ||
<emu-alg> | ||
1. Return %Iterator%. | ||
</emu-alg> | ||
</emu-clause> | ||
|
||
<emu-clause id="sec-set-iteratorprototype-constructor"> | ||
<h1>set Iterator.prototype.constructor</h1> | ||
<p>The value of the [[Set]] attribute is a built-in function that takes an argument _v_. It performs the following steps when called:</p> | ||
<emu-alg> | ||
1. Let _O_ be ? RequireObjectCoercible(*this* value). | ||
1. If _O_ is %Iterator.prototype%, then | ||
1. Return *undefined*. | ||
1. Let _desc_ be ? _O_.[[GetOwnProperty]](*"constructor"*). | ||
1. If IsDataDescriptor(_desc_) is *true* and _desc_.[[Writable]] is *false*, then | ||
1. Return *undefined*. | ||
1. Let _newDesc_ be the PropertyDescriptor { [[Value]]: _v_, [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *true* }. | ||
1. Perform ? _O_.[[DefineOwnProperty]](*"constructor"*, _newDesc_). | ||
1. Return *undefined*. | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. if we're really going to do this it should be an AO that many things can share, since the only things that potentially change are Iterator.prototype and the property name There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. that can be an editorial thing we address in the PR to 262 |
||
</emu-alg> | ||
</emu-clause> | ||
|
||
<emu-note> | ||
<p>Unlike the *"constructor"* property on most built-in prototypes, for web-compatibility reasons this property must be an accessor.</p> | ||
</emu-note> | ||
</emu-clause> | ||
|
||
<emu-clause id="sec-iteratorprototype.map"> | ||
|
@@ -563,9 +591,34 @@ <h1>Iterator.prototype.find ( _predicate_ )</h1> | |
|
||
<emu-clause id="sec-iteratorprototype-@@tostringtag"> | ||
<h1>Iterator.prototype [ @@toStringTag ]</h1> | ||
<p>The initial value of the @@toStringTag property is the String value "Iterator".</p> | ||
<p>`Iterator.prototype[@@toStringTag]` is an accessor property with attributes { [[Enumerable]]: *false*, [[Configurable]]: *true* }. The [[Get]] and [[Set]] attributes are defined as follows:</p> | ||
|
||
<emu-clause id="sec-get-iteratorprototype-@@tostringtag"> | ||
<h1>get Iterator.prototype [ @@toStringTag ]</h1> | ||
<p>The value of the [[Get]] attribute is a built-in function that requires no arguments. It performs the following steps when called:</p> | ||
<emu-alg> | ||
1. Return *"Iterator"*. | ||
</emu-alg> | ||
</emu-clause> | ||
|
||
<emu-clause id="sec-set-iteratorprototype-@@tostringtag"> | ||
<h1>set Iterator.prototype [ @@toStringTag ]</h1> | ||
<p>The value of the [[Set]] attribute is a built-in function that takes an argument _v_. It performs the following steps when called:</p> | ||
<emu-alg> | ||
1. Let _O_ be ? RequireObjectCoercible(*this* value). | ||
1. If _O_ is %Iterator.prototype%, then | ||
1. Return *undefined*. | ||
1. Let _desc_ be ? _O_.[[GetOwnProperty]](@@toStringTag). | ||
1. If IsDataDescriptor(_desc_) is *true* and _desc_.[[Writable]] is *false*, then | ||
1. Return *undefined*. | ||
1. Let _newDesc_ be the PropertyDescriptor { [[Value]]: _v_, [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *true* }. | ||
1. Perform ? _O_.[[DefineOwnProperty]](@@toStringTag, _newDesc_). | ||
1. Return *undefined*. | ||
</emu-alg> | ||
</emu-clause> | ||
|
||
<emu-note> | ||
<p>Unlike the @@toStringTag on most built-in classes, for web-compatibility reasons this property must be writable.</p> | ||
<p>Unlike the @@toStringTag property on most built-in prototypes, for web-compatibility reasons this property must be an accessor.</p> | ||
</emu-note> | ||
</emu-clause> | ||
</emu-clause> | ||
|
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Per request of @erights this should be an error, to emulate strict rather than sloppy assignment.