toString of anonymous function

[James Graham-7]

The text in 15.3.4.2 Function.prototype.toString () says:

"An implementation-dependent representation of the function is returned.
This representation has the syntax of a FunctionDeclaration"

Is there a reason this is a FunctionDeclaration rather than a
FunctionExpression? In particular what is the expected behavior for
toString of an anonymous function?

var f = function() {}
f.toString()

In the engines I tried this gave a result like

"function () {}"

with only whitespace differences. This doesn't match the
FunctionDeclaration production due to the lack of an identifier. Whilst
the engine could invent an identifier, I don't see what the advantage
would be and I would be worried about breaking existing code by doing
so. Instead, I think it would be nice to align the spec with reality here.
_______________________________________________
es-discuss mailing list
es-discuss@...
https://mail.mozilla.org/listinfo/es-discuss

[Allen Wirfs-Brock-2]

There has been a lot of discussion of Function.prototype.toString on this and the es5-discuss lists. Basically we didn't reach any consensus on what it should do so there was no change for ES5.  The subject can be reopened for ES Harmony.

Allen

>-----Original Message-----
>From: es-discuss-bounces@... [mailto:es-discuss-
>bounces@...] On Behalf Of James Graham
>Sent: Friday, August 28, 2009 6:41 AM
>To: es-discuss@...
>Subject: toString of anonymous function
>
>The text in 15.3.4.2 Function.prototype.toString () says:
>
>"An implementation-dependent representation of the function is returned.
>This representation has the syntax of a FunctionDeclaration"
>
>Is there a reason this is a FunctionDeclaration rather than a
>FunctionExpression? In particular what is the expected behavior for
>toString of an anonymous function?
>
>var f = function() {}
>f.toString()
>
>In the engines I tried this gave a result like
>
>"function () {}"
>
>with only whitespace differences. This doesn't match the
>FunctionDeclaration production due to the lack of an identifier. Whilst
>the engine could invent an identifier, I don't see what the advantage
>would be and I would be worried about breaking existing code by doing
>so. Instead, I think it would be nice to align the spec with reality
>here.
>_______________________________________________
>es-discuss mailing list
>es-discuss@...
>https://mail.mozilla.org/listinfo/es-discuss

_______________________________________________
es-discuss mailing list
es-discuss@...
https://mail.mozilla.org/listinfo/es-discuss

[Mark S. Miller-2]

On Fri, Aug 28, 2009 at 8:35 AM, Allen
Wirfs-Brock<Allen.Wirfs-Brock@...> wrote:
> There has been a lot of discussion of Function.prototype.toString on this and the es5-discuss lists. Basically we didn't reach any consensus on what it should do so there was no change for ES5.  The subject can be reopened for ES Harmony.

Already is: http://wiki.ecmascript.org/doku.php?id=strawman:function_to_string


--
    Cheers,
    --MarkM
_______________________________________________
es-discuss mailing list
es-discuss@...
https://mail.mozilla.org/listinfo/es-discuss