Strictness of BindingIdentifiers of functions with "use strict" directives

# Kevin Gibbons (9 years ago)

Consider the following code: function static(){'use strict'}.

As far as I can tell, this is a legal Script. It would not be if static is considered to be in strict mode code, since it would then be a reserved word. However, the directive only makes the associated function code strict (10.2.1), which does not include its BindingIdentifier:

Function code is defined to be "source text that is parsed to supply the value of the [[ECMAScriptCode]] and [[FormalParameters]] internal slots of an ECMAScript function object" (10.2). In particular, this does not appear to include the name of a function declaration or expression.

Despite its apparent legality, all of [v8, SpiderMonkey, JavaScriptCore, ChakraCore, Nashorn] do not allow it, nor does any parser I tried except Shift.

Is this intended to be legal?

Consider the following code: `function static(){'use strict'}`.

As far as I can tell, this is a legal Script. It would not be if `static`
is considered to be in strict mode code, since it would then be a reserved
word. However, the directive only makes the associated function code strict
(10.2.1), which does not include its BindingIdentifier:

Function code is defined to be "source text that is parsed to supply the
value of the [[ECMAScriptCode]] and [[FormalParameters]] internal slots of
an ECMAScript function object" (10.2). In particular, this does not appear
to include the name of a function declaration or expression.

Despite its apparent legality, all of [v8, SpiderMonkey, JavaScriptCore,
ChakraCore, Nashorn] do not allow it, nor does any parser I tried except
Shift.

Is this intended to be legal?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20160323/3d33eb3c/attachment.html>

# Mike (9 years ago)

There was a good discussion about this around this time last year on the ECMAScript BugZilla tracker:

ecmascript#4243

Allen showed how this is a little less straightforward than it might first appear, but he proposed a solution that could work.

There was a good discussion about this around this time last year on the 
ECMAScript BugZilla tracker:

https://bugs.ecmascript.org/show_bug.cgi?id=4243

Allen showed how this is a little less straightforward than it might 
first appear, but he proposed a solution that could work.