Re: PATCH: completion caching layer

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

Adam Spiers wrote:

> ...
>
> > > I agree entirely.  That way also I could make _perl_modules set a
> > > default style (if one is not already set) when the function is loaded,
> > > rather than each time it's invoked.  But where would it appear in the
> > > context?  My knowledge of this stuff is slightly weak, I'm afraid.
> > 
> > After the last colon:
> > 
> >   zstyle -t ":completion:${curcontext}:" ...
> >                                        ^here
> > 
> > I.e., instead of the tag (if you would use tags).
> 
> OK.  Although that doesn't solve the problem of having to set a
> default for each of the commands _perl_modules completes.  Maybe
> 
>   zstyle ':completion:::::RPMs' cache-policy _rpms_caching_policy
> 
> would work?

For use by the completion function itself? We decided some time ago
that they shouldn't set styles themselves, only look them up.

So, instead of adding what you suggest (which most probably wouldn't
work because there are other things in the context, e.g. the command
name), one would use the return value of zstyle:

  zstyle -s ":completion:${curcontext}:RPMs" cache-policy foo ||
      foo=_rpms_caching_policy

I.e., the return value of zstyle is non-zero iff the style is not set
for that context.


> Incidentally I couldn't find anything in the documentation to explain
> the difference between e.g. ::: and :*:*: in contexts.  Did I miss it?

Err. Pattern matching. `:::' matches only itself, `:*:*:' matches
`::perl:' and `::perl:argument-rest' and `:complete:perl:argument-rest' 
and `predict:complete:perl:argument-rest'.

The patterns given when defining styles are really only matched agains 
the context-strings given when looking up styles. Normal shell pattern 
matching, nothing special there. Only the sorting of the patterns is
something not used elsewhere.

Bye
 Sven


--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de