Re: [PATCH] tcsh-completion re-using git-completion.bash

From: Marc Khouzam <marc.khouzam@gmail.com>
Date: Nov 16, 2012, 15:48 UTC
Message-ID: <CAFj1UpHLf2je_+b1e5B_5thZ03UYVmW=CWhAh63kNRCbke0kQw@mail.gmail.com>
In-Reply-To: <CAMP44s1RtOj6LKCNJ8SX8KSA8eNCMZ+4D-VfQ+WtXju-KhG8ng@mail.gmail.com>

On Fri, Nov 16, 2012 at 10:33 AM, Felipe Contreras <felipe.contreras@gmail.com> wrote:

Show 34 quoted lines

> On Fri, Nov 16, 2012 at 3:39 PM, Marc Khouzam <marc.khouzam@gmail.com> wrote:
>> On Thu, Nov 15, 2012 at 8:41 PM, Felipe Contreras
>> <felipe.contreras@gmail.com> wrote:
>>> On Thu, Nov 15, 2012 at 12:51 PM, Marc Khouzam <marc.khouzam@gmail.com> wrote:
>>>> The current tcsh-completion support for Git, as can be found on the
>>>> Internet, takes the approach of defining the possible completions
>>>> explicitly.  This has the obvious draw-back to require constant
>>>> updating as the Git code base evolves.
>>>>
>>>> The approach taken by this commit is to to re-use the advanced bash
>>>> completion script and use its result for tcsh completion.  This is
>>>> achieved by executing (versus sourcing) the bash script and
>>>> outputting the completion result for tcsh consumption.
>>>>
>>>> Three solutions were looked at to implement this approach with (A)
>>>> being retained:
>>>>
>>>>   A) Modifications:
>>>>           git-completion.bash and new git-completion.tcsh
>>>
>>> As I said, I don't think this is needed. It can be done in a single
>>> stand-alone script without modifications to git-completion.bash.
>>>
>>> This works:
>>
>> Thank you for taking the time to try things out.
>>
>> What you suggest below is an improvement on solution (C).
>> I had chosen (A) instead because (C) creates a third script
>> which gets generated each time a new shell is started.
>
> We could generate the script only when it's not already present. The
> disadvantage is that if this script is updated, the helper one would
> not.

I didn't like that too much either.

> One way to solve the problem would be to append the current
> version of git, and figure a way to query it out. Another would be to
> checksum it. But then again, maybe it's more expensive to check the
> version or checksum than just write the file again.

Yeah, I'm also thinking that re-generating the script is not bad enough to introduce this complexity.

> Is it possible to just check if this is a login shell?

I think it would be nice to allow the user to manually source git-completion.tcsh, in case they want to make manual modifications to it.

I think the most user-friendly option is to actually re-generate the script each time. It feels wrong, but it works well :)

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>>> set called = ($_)
>>
>> I fought with this a lot before posting to the list.
>> It seems that $_ is not set when a double sourcing
>> happens.  Testing the solution as an actual user
>> showed me that when I start a new shell it
>> sources ~/.tcshrc, which then sources ~/.git-completion.tcsh
>> and then $_ is empty for some reason.
>>
>> I couldn't find another way to figure out where the script
>> is located, which is why I had to force the user to use
>> ${HOME} for everything.
>
> Ah :(
>
> --
> Felipe Contreras