Re: condition-case

[Ted Zlatanov <tzz@lifelogs.com>]

On Fri, 10 Dec 2010 16:43:46 -0500 Stefan Monnier <monnier@iro.umontreal.ca> wrote: 

PJB> There's no condition-bind to wrap over.
PJB> I'm not sure it would be possible to implement handler-bind without
PJB> patching the virtual machine.
>> Stefan, WDYT?  Is `condition-bind' possible in today's GNU Emacs?  I
>> mean does the VM have any constraints that would block it?

SM> There used to be some allowance made in the C code for such a feature,
SM> but since it was never used it bit-rotted and has "recently" been more
SM> actively removed.  So adding a condition-bind or something like that
SM> would require a fair bit of work, I think.  There is still some support
SM> for part of it since errors can jump into the debugger, but currently
SM> the debugger cannot return to the source of the error, it can only jump
SM> back up the stack like condition-case does.

I also notice no one has complained in the last few years that
`condition-case' is insufficient.  So maybe `condition-bind' is simply
not necessary.

Ted