bug#68075: 30.0.50; New special form `handler-bind`

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

>> >> +@var{handler} is called in the dynamic context where the error
>> >> +happened, without first unwinding the stack, meaning that all the
>> >> +dynamic bindings are still in effect,
>> >
>> > Should we tell something about the effects of lexical-binding on those
>> > "dynamic bindings"?
>> 
>> It's not related to `handler-bind` in any case, so if
>> we want to say something about it, we should do it elsewhere (and
>> I think we already do when we discuss lexical binding).
>
> Maybe I'm confused by your use of "dynamic context" and "dynamic
> bindings" in that passage, which somehow hinted on dynamic vs lexical
> binding.

Of course: "dynamic context" refers to things that include dynamically
bound variable (as well as the set of active catch tags, error handlers,
and unwind-protect forms), and does not include statically bound
variables.  `handler-bind` is different from `condition-case` in the way
it interacts with that dynamic context.  But for statically bound
variables, well, they obey the rules of static scoping so there's
nothing to influence here.

> If this is irrelevant, maybe try to reword the text so that
> this potentially confusing terminology is not used?

Could you give an example piece of code where this "confusing
terminology" makes you unsure how things would work?


        Stefan