Re: ignored-patterns giving correction a go

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

On Mar 17, 10:05am, Sven Wischnowsky wrote:
} Subject: Re: ignored-patterns giving correction a go
}
} I use something like:
} 
}   zstyle :completion::::: completer _next_tags _expand _complete \
}                                     _complete _match _correct \
}                                     _approximate _prefix

BTW, there's no doc for _next_tags ... what happens if you invoke it as
a widget but it's NOT in your completer list?

}   zstyle ':completion:*:complete-2:*' prefer-ignored yes
}   zstyle ':completion:*:(correct|approximate|prefix)-1:*' prefer-ignored yes

Obviously the documentation for using a completer twice doesn't belong
just under the matcher-list spec any more.

} All this alternate-set stuff looks like a hack. [...] The problem is
} that if we remove the alternate set stuff for new completion, we'll
} have trouble re-implementing the behaviour of $fignore, at least when
} we want it to have the exact same effect.

The tricky bit is really the fail-over behavior, isn't it?  That is,
the way the alternate set is automatically used if the "real" set is
empty?

So what if we just made the alternate set a group of its own, on the
same level as the -default- group, e.g. -alternate-.  Change the -a
option of compadd to require an argument, `-a alternate-group-name',
that, when used with `-[JV] group-name' and `-F array' names the group
into which the completions matching the -F patterns are placed; the
sorting of that group is the same as for the -[JV], -[12] apply, etc.
When no -a is given the -alternate- group is used by -F, and when -a
is given with no -[JV], the completions that don't match the -F pattern
go into -default-.

(I'd almost rather pick a different option that -a and eliminate -a
entirely, to break noisily any completion functions that now use -a
without an argument; but -A is already taken, as are most of the other
sensible letters.)

Then make the default completion behavior be as if the tag-order were
the array (-default- -alternate-).  If in any context the tag-order
style is overridden, the user must explicitly name -alternate- (or any
group passed with -a by other completion functions) to have it used.
Document this, of course.

For the special case of fignore, _files and _path_files can use -a
to name multiple alternate group names, and play with the default
tag-order the way _files already does for globbed-files directories
all-files.  Does that sound like it'll (1) work and (2) be less of a
hack than the present behavior?

An advantage is that you can cause alternates from several groups to
accumulate all in the same place, so for _files you might have the
groups globbed-files directories all-ignored-files all-files, where
all-ignored-files includes both files and paths that matched $fignore.
Not that this is how I'm suggesting it work, I'm just using it by way
of example.

One problem is that I don't see how you can eliminate the current
alternate-set support from the C code and still have fignore work for
old compctl, but maybe you have an idea for going about that.  Or
maybe that code would just go unused in the new system.

(What happens right now if you call
	compadd -V group ...
and later
	compadd -J group ...
that is, specify some sorted and some unsorted matches for the same
group?)

(What's the point of setting groups[2] inside the _tags loop in _files?
it doesn't appear to get used anywhere after line 19 where it's copied
into the opts array.)

} Some more about 10134: after having thought about it some more, I
} begin to like the suggestion with `tag-order tag=method ...' with the
} shortcut `tag-order foo'.

The only issue I have with this is that it increases the number of
similar zstyle commands one must give to configure a behavior.  Here's
your example from 10134:

}   zstyle ... tag-order foo=files bar=files
}   zstyle '...:foo' file-patterns '*.ps'

Presumably the '...' part in both of those lines is, in many cases,
going to be the same.  And then you need to repeat it _again_ to give
the patterns for `bar'.  I find myself wishing for some way to merge
them, maybe something like

    zstyle ... tag-order foo=files bar=files \
	    + foo file-patterns '*.ps' \
	    + bar file-patterns '*.pdf'

That specific example would make the word `+' magic, which might not be
a good idea ... but we're running out of metacharacters that don't need
to be annoyingly quoted.

I was going to try to reply in some detail to 10134, but I'm out of time
and (other than preferring the tag=method form to having yet _another_
set of styles to name method-tags) it's probably better if Sven just
tries things out and reports how well he thinks they work.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com