Explicit colons in zstyle

Explicit colons in zstyle

[Jesper Nygårds]

Is there something special about how a style should be expressed when
it relates to "completer"?. I started noticing in some examples from
The Book, that completer is not treated exactly the same as other
styles.

Here's the well know most-recent-file example:

zstyle ':completion:most-recent-file::::' completer _menu _files _match
zstyle ':completion:most-recent-file:*' file-sort modification
zstyle ':completion:most-recent-file:*' hidden all
zstyle ':completion:most-recent-file:*' file-patterns '*(.):normal\ files'

Is there a reason why the first line contains so many colons? To me it
looks like it would be equivalent to the other lines, containing an
asterisk.

The same pattern in the next example:

zstyle ':completion:history-complete::::' completer _history
zstyle ':completion:history-complete:*' remove-all-dups true
zstyle ':completion:history-complete:*' sort true


Then, I saw this, also from The Book:

zstyle ':completion::*:::' completer _complete _prefix

The text says that the asterisk is necessary to make the _prefix
completer match, but I can't understand why the simpler "zstyle
':completion:*' completer _complete _prefix" wouldn't work.

I'm obviously missing something. Perhaps someone can enlighten me?

Re: Explicit colons in zstyle

[Peter Stephenson]

On Thu, 29 Mar 2012 20:59:25 +0200
Jesper Nygårds <jesper.nygards@gmail.com> wrote:
> Is there something special about how a style should be expressed when
> it relates to "completer"?. I started noticing in some examples from
> The Book, that completer is not treated exactly the same as other
> styles.
> 
> Here's the well know most-recent-file example:
> 
> zstyle ':completion:most-recent-file::::' completer _menu _files _match
> zstyle ':completion:most-recent-file:*' file-sort modification
> zstyle ':completion:most-recent-file:*' hidden all
> zstyle ':completion:most-recent-file:*' file-patterns '*(.):normal\ files'
> 
> Is there a reason why the first line contains so many colons? To me it
> looks like it would be equivalent to the other lines, containing an
> asterisk.

I think the book (Oliver wrote that bit) is just making the point that
the completer style is always looked up with most of the fields empty.
By recognising the fact you can make it match many of the fields
exactly.

The only difference with replace the :::: with :* is that it becomes
according to the rules a less exact match, so that if you happened to
have both definitions the former would take precedence.  That's not
something you typically need to worry about.

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/

Re: Explicit colons in zstyle

[Jesper Nygårds]

On Fri, Mar 30, 2012 at 9:41 PM, Peter Stephenson
<p.w.stephenson@ntlworld.com> wrote:
> I think the book (Oliver wrote that bit) is just making the point that
> the completer style is always looked up with most of the fields empty.
> By recognising the fact you can make it match many of the fields
> exactly.
>
> The only difference with replace the :::: with :* is that it becomes
> according to the rules a less exact match, so that if you happened to
> have both definitions the former would take precedence.  That's not
> something you typically need to worry about.

I see. Thank you for the explanation.