ES4 draft: Error classes

Lars Hansen lhansen at adobe.com
Fri Mar 21 08:12:37 PDT 2008


> -----Original Message-----
> From: Brendan Eich [mailto:brendan at mozilla.org] 
> Sent: 20. mars 2008 15:31
> To: Lars Hansen
> Cc: Mike Shaver; es4-discuss Discuss; P T Withington
> Subject: Re: ES4 draft: Error classes
> 
> On Mar 20, 2008, at 12:02 PM, Lars Hansen wrote:
> 
> >> //@line 123 "awesomeLib.js"
> >> throw Error("ow");
> >>
> >> The error's line number is 123, file is "awesomeLib.js".  We have 
> >> some bits in there like a limit on the filename length
> >> (1024) and a cap on the line length (10x our "natural" line length,
I 
> >> think); eminently negotiable.
> >
> > OK.  We would need to accomodate other input sources than files at a

> > minimum, maybe an optional string at the end (the file name could be

> > optional too).
> 
> The filename is optional, defaults to "".
> 
> You could (absent security concerns) subsume filename under 
> URL or URI. "-" is an old Unix convention meaning stdin. What 
> other input sources did you have in mind?

Considering multiple execution environments, the list looks at least
like this:

* files
* inline scripts
* event handlers
* linked scripts (URLs I guess)
* javascript: URLs
* "eval" text
* "new Function" text
* stdin and similar streams

I don't know how much detail is useful nor how much can really be
revealed
without becoming insecure; clearly depends on the environment.

> >> I'm not sure we turned it on for content, because of spoofing 
> >> concerns, but I'm pretty sure we use it for our chrome.
> >
> > If you could dig up a discussion thread or actual person to
illuminate 
> > that concern, it would probably be helpful.
> 
> /me raises hand
> 
> See https://bugzilla.mozilla.org/show_bug.cgi?id=243359 for 
> the history, which includes the inevitable "sometimes I want 
> the revised source coords, sometimes you want the originals" perplex.

Yeah, that one was bound to come up.

Thanks for the reference, will read it and ponder the options.

--lars



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