Re: emacs: are multi-char parentheses possible?

[Andreas Röhler]

On 09.06.2014 17:38, Stefan Monnier wrote:
> > Do you know if it is possible for Emacs to handle a pair of multi-char
> > parentheses?
>
> Yes, I do.  I also know the answer is not just a plain boolean.
>
> > Take << and >> for example,
> >
> > (setq-local syntax-propertize-function (syntax-propertize-rules
> >                                            ("\\(<\\)<" (1 "(>"))
> >                                            (">\\(>\\)" (1 ")<"))))
> >
> > show-paren-mode can highlight "<<" and ">>" but up-list aren't aware of
> > them.
>
> up-list should handle this just as well as show-paren and
> for/backward-sexp (and does, in my tests).
>
> Maybe you tried a "forward up-list" where the closing ">>" hadn't yet been
> syntax-propertized?
>
> This technique has some downsides, but in the case of << ... >> it might
> work well enough.
>
> For things like "begin...end" it's more annoying (e.g. backward word
> will stop right between the "b" and the "egin" and forward-word will
> stop right between "en" and "d").  For those, SMIE might be a better
> option (which uses hooks in show-paren and forward-sexp to try and make
> them do The Right Thing, tho the up-list case is only 90% working).
>
>
>          Stefan

With thingatpt you may specify arbitrary strings as delimiters.
Maybe that's an option in context also.

Andreas