Re: [TCLCORE] Tcl-Core Digest, Vol 30, Issue 10

[Joe E. <jen...@fl...>]

Neil Madden wrote:
> Donal K. Fellows wrote:
> > Neil Madden wrote:
> >> I'd leave out entirely the glob-matching on errorCode, and let
> >> people do
> >> this with [switch] if they want it:
> > No. That's advocating a lack of vision. If we make it *easy* to trap
> > specific errors by errcode, people will do so. People don't now
> > because
> > it is too hard.
>
> I just don't see any evidence for this statement (the use-cases will
> follow if we just implement this!).

There has been a longstanding desire that people [*] make
better use of -errorcode, but there's a vicious cycle:
nobody bothers to use meaningful -errorcodes because nobody
bothers to check -errorcode because there's no convenient
way to do so.

try/onerror would at least break that part of the cycle.

(FWIW, I don't think try/onerror will be immediately useful either,
and am not sure that it will _ever_ be useful -- perhaps meaningful
-errorcodes wouldn't be that helpful even if we did have them --
but it's worth a try.)


--Joe English


[*] and by "people" I mean "including core maintainers",
and by "including core maintainers" I mean "especially".