bug#29847: [PATCH] import: pypi: Stay in the REPL if fail to get a source

[ludo@gnu.org (Ludovic Courtès)]

Hi Oleg,

Oleg Pykhalov <go.wigust@gmail.com> skribis:

> ludo@gnu.org (Ludovic Courtès) writes:
>
>> Ping!
>>
>> ludo@gnu.org (Ludovic Courtès) skribis:
>>
>>> OK for the patch, but please simply replace ‘leave’ with ‘warning’.
>
> I think the patch is no longer needed, because ‘pypi->guix-package’
> returns false (‘#f’) and REPL survives if a package doesn't exist:
>
> scheme@(guix import pypi)> (pypi->guix-package "psutil")
>
> Starting download of /tmp/guix-file.9Q8PGN
> From https://pypi.python.org/packages/e2/e1/600326635f97fee89bf8426fef14c5c29f4849c79f68fd79f433d8c1bd96/psutil-5.4.3.tar.gz...
>  …4.3.tar.gz  403KiB                  1.6MiB/s 00:00 [##################] 100.0%
>
> Starting download of /tmp/guix-file.Vn9nDZ
> From https://pypi.python.org/packages/e5/cc/6dd427e738a8db6d0b66525856da43d2ef12c4c19269863927f7cf0e2aaf/psutil-5.4.3-cp27-none-win32.whl...
>  …7-none-win32.whl  216KiB            1.3MiB/s 00:00 [##################] 100.0%
> $3 = (package (name "python-psutil") #; more fields here)
> scheme@(guix import pypi)> (pypi->guix-package "psutils") ; ‘psutils’ doesn't exist in ‘pypi’
> $4 = #f
>
> WDYT?

Indeed it should no longer be needed.

>> Note that at the REPL you can always do:
>>
>>   (catch 'quit (lambda () …) (const #f))
>
> Thank you!  Based on this I wrote a macro:
>
>    (define-macro (try function)
>     `(catch 'quit (lambda () ,function) (const #f)))
>
> but I don't know how to make it available after invoking ‘guile’ in
> Bash.  Putting the macro in ‘~/.guile’ doesn't help unfortunately.

I just tried and it works for me.  Note that ~/.guile is only read when
starting an interactive Guile (a REPL), not when starting guile to run a
program.

Thanks,
Ludo’.