Adding new completions to zsh

Adding new completions to zsh

[Eric Mangold]

Hello,

I've written completion functions for the 'mktap' and 'twistd' command of 
the Twisted project, http://twistedmatrix.com and I would like advice on 
getting this functionality included in zsh.

The problem I'm facing is keeping the completions in zsh up-to-date.  
Twisted development happens at a fairly rapid pace and while command 
options aren't changing every day, in my judgement it would be annoying 
for our users (many of whom use zsh already) to be stuck with the static 
set of completion functionality bundled in any given zsh release.

My idea for allowing greater flexibility is to bundle the actual zsh 
completion functionality as part of the Twisted distribution and give zsh 
a "stub" that will use the completion functions that are bundled with 
Twisted.

Has anyone ever done this before? What do you all think?


	-Eric

P.S. maybey this should this be on zsh-dev, but I assume everyone reads 
zsh-users.

Re: Adding new completions to zsh

[Peter Stephenson]

On Wed, 25 Feb 2004 20:39:22 -0700
Eric Mangold <teratorn@world-net.net> wrote:
> My idea for allowing greater flexibility is to bundle the actual zsh 
> completion functionality as part of the Twisted distribution and give zsh 
> a "stub" that will use the completion functions that are bundled with 
> Twisted.

This sounds OK... I presume you're going to add some hook to the main Twisted
program (or some configuration utility) that reports the installation location
so that the functions distribution with zsh can find the functions
distributed with Twisted.

As far as I know, nobody's done that yet, but it seems a sensible way of
doing it.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: Adding new completions to zsh

[Eric Mangold]

On Thu, 26 Feb 2004 10:29:13 +0000, Peter Stephenson <pws@csr.com> wrote:

> On Wed, 25 Feb 2004 20:39:22 -0700
> Eric Mangold <teratorn@world-net.net> wrote:
>> My idea for allowing greater flexibility is to bundle the actual zsh
>> completion functionality as part of the Twisted distribution and give 
>> zsh
>> a "stub" that will use the completion functions that are bundled with
>> Twisted.
>
> This sounds OK... I presume you're going to add some hook to the main 
> Twisted
> program (or some configuration utility) that reports the installation 
> location
> so that the functions distribution with zsh can find the functions
> distributed with Twisted.

Since Twisted is a Python package I can (fairly easily) use the standard 
python mechanisms to locate files or otherwise pull data out of that 
package.

So the first time someone tries one of the completions it will call python 
to acquire the completion info, and then I guess I'll cache that in a 
global variable to speed it up for further completions done in that shell 
session.


	-Eric

Re: Adding new completions to zsh

[Oliver Kiddle]

Eric Mangold wrote:

> My idea for allowing greater flexibility is to bundle the actual zsh 
> completion functionality as part of the Twisted distribution and give zsh 
> a "stub" that will use the completion functions that are bundled with 
> Twisted.
> 
> Has anyone ever done this before? What do you all think?

It's never been done before but it makes some sense.

Thinking about how this could work, the function distributed with zsh
could start with something like this:

  local dir FPATH="$FPATH"

  dir=${commands[twistd]:h:h}/share/twistd
  if [[ -r $dir/_twistd ]]; then
    fpath=( $dir $fpath )
    autoload -XU
  fi

The dir assignment is a crude way of trying to find the directory
containing the function in the twisted distribution. Hopefully you have
some hook which will do a better job. It then checks if it has found
the function. If so, it adds the directory to beginning of the function
search path and uses autoload to load the replacement function.

After this section, we could fallback on a potentially out-of-date
completion for twistd. It'd be good if the zsh CVS view of that could
be kept reasonably up-to-date though.

Oliver

Re: Adding new completions to zsh

[Dominic Mitchell]

On Wed, Feb 25, 2004 at 08:39:22PM -0700, Eric Mangold wrote:
> My idea for allowing greater flexibility is to bundle the actual zsh 
> completion functionality as part of the Twisted distribution and give zsh 
> a "stub" that will use the completion functions that are bundled with 
> Twisted.

Would it not make more sense to get your extensions bundled with Twisted
and then installed in the site-functions directory?  This is what the
FreeBSD portupgrade commands do and it works great!

-Dom

Re: Adding new completions to zsh

[Eric Mangold]

On Thu, 26 Feb 2004 21:37:04 +0000, Dominic Mitchell 
<dom@happygiraffe.net> wrote:

> On Wed, Feb 25, 2004 at 08:39:22PM -0700, Eric Mangold wrote:
>> My idea for allowing greater flexibility is to bundle the actual zsh
>> completion functionality as part of the Twisted distribution and give 
>> zsh
>> a "stub" that will use the completion functions that are bundled with
>> Twisted.
>
> Would it not make more sense to get your extensions bundled with Twisted
> and then installed in the site-functions directory?  This is what the
> FreeBSD portupgrade commands do and it works great!

I've considered this, however I don't believe it is ideal for this 
specific situation. There are a couple different scenarios where using the 
completion info installed by Twisted's installion routine would be 
undesireable.

First, there's no guarantee that the user even has Twisted /installed/. It 
is very common for the users and developers of Twisted to be working 
directly out of a CVS checkout. They will do this by adding the directory 
containing the CVS checkout to their PYTHONPATH env var.

Secondly, the user may have a release version of Twisted installed yet be 
using another version somewhere else. Such as CVS or having simply 
extracted a newer Twisted release tarball in their home dir and set 
PYTHONPATH accordingly.

So asking python is the only sure way to provide info that is accurate for 
what the user is presently doing.

	-Eric