Re: Writing syntax-propertize-function for strings in code in strings, etc

[Dmitry Gutov <dgutov@yandex.ru>]

On 28.10.2012 19:46, Stefan Monnier wrote:
>>>>> Yes, one "push <inner-syntax-table>" and one "pop".
>>>> So, I don't see the usefulness of the <inner-syntax-table> value in the
>>>> simple case of embedding code in the same language.
>>> It's for the other cases: strings with strings and comments within strings.
>> Okay. I guess I just don't know [well enough] any languages with different
>> embedded syntaxes.
>
> I mentioned Postscript as a language that allows strings within strings
> (Postscript strings are delimited by parentheses).

I see.

>>> Without knowing the inner syntax table, it's pretty difficult to know
>>> what can be skipped (unless we assume that the "push" can only be marked
>>> with a `syntax-table' text-property).
>> Indeed. But I think it's a reasonable assumption.
>
> It's not for Postscript strings, I think.
>
>> In all cases I can think about the "region opener" is at least two
>> characters long, and it often depends on the context (like only inside
>> a string).
>
> OTOH, if we really need to find the inner syntax-table, we could ask
> syntax-ppss to give the state right before the "pop", which will also
> immediately tell us where is the matching push.
> So maybe it's an acceptable workaround (provide a config variable to
> either use syntax-ppss or assume that a push can only be within
> a syntax-table text-property).

Sounds good to me.

>> Let's move point inside an embedded code region, maybe several levels
>> deep.  Now we want to call `forward-sexp'.  How will it know the
>> effective syntax-table value at that position?
>
> That's not a new problem, actually, since if you start a `forward-sexp'
> from within a string or within a comment you already get
> similar problems.

True, although with those it's mostly a non-problem, AFAICT: jumping 
forward or back from comments works just fine, and jumping solely 
between strings makes a certain amount of sense.

> PS: My secret longer-term agenda for world domination might include
>      using push/pop for all strings and comments as well.

Could you point to the use case?
I think this might be good for e.g. comments in regexps, but that's 
already going to be one of the uses for "code in strings", no?

P.S. Sorry for offtopic, but I've been receiving this kind of "message 
undelivered" messages for the past few weeks from 
mailer-daemon@yandex.ru, one for each email I sent you, each with 
considerable delay:

<monnier@IRO.UMontreal.CA>: connect to
     perlin.IRO.UMontreal.CA[132.204.24.51]:25: Connection timed out

Is this a problem on your end, or should I switch to another SMTP server?

--Dmitry