ES4 draft: Error classes

Mike Shaver mike.shaver at
Fri Mar 7 04:52:08 PST 2008

On Fri, Mar 7, 2008 at 7:31 AM, Lars Hansen <lhansen at> wrote:
>  The chances that the spec will *require* a useful backtrace
>  (quasi-fixed format and requirements about which frames may or
>  may not be in it, say) or source location information to be
>  created for E.p.throw are probably quite low.  Realistically
>  what we could hope for is a statement of intent and
>  well-defined hooks for implementations who want to support
>  something, like the case is for the ControlInspector proposal
>  (which is optional).  Adding file/line info to errors thrown
>  by the language implementation looks easier to do across
>  diverse runtimes, but I don't know for sure.

Indeed, I wasn't expecting anything normative other than that
E.p.throw threw |this|, but informative (SHOULD? MAY?) text describing
it as a place for implementors to hook state modifications to aid in

I'll see if I can figure out how to write a concrete proposal, maybe
next week; please feel free to beat me to this, lazylist!


More information about the Es4-discuss mailing list