GNU bug report logs - #45972
[PATCH] Add julia-json with dependencies

Previous Next

Full log

Message #20 received at 45972 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Nicolò Balzarotti <anothersms <at> gmail.com>
Cc: 45972 <at> debbugs.gnu.org
Subject: Re: [bug#45972] [PATCH] Add julia-json with dependencies
Date: Thu, 28 Jan 2021 14:10:15 +0100

Buon giorno!

Nicolò Balzarotti <anothersms <at> gmail.com> skribis:

>> My understanding is that the first patch expects the source file name to
>> match the Julia package name.
>
> That's correct, we use it in the build system.
>
>> IMO, that shouldn’t be the case.
>
> At first I wasn't sure it was ok, but it went on through the revision
> process when I submitted the first package (Compat) so I tought it was fine.

If it was me it was probably an oversight, I’m sorry about that.

>> Can we either extract the Julia package name from metadata that’s in
>> the package itself (?), or otherwise pass it to all the phases via
>> ‘julia-build-system’?
>
> Sure, I'd just read it from Package.toml (nowadays almost all the
> packages have this file, and for when it's missing we also have the
> julia-create-package-toml procedure that creates it).
>
> The file is toml, but I don't see a toml parser in guix.  So, I'd use a
> function like the following:
>
> #+begin_src scheme
> (define (package.toml->name file)
>   (call-with-input-file file
>     (lambda (in)
>       (let loop ((line (read-line in 'concat)))
>         (if (eof-object? line)
>             #f                          ;What to do?
>             (let ((m (string-match "name\\s*=\\s*\"(.*)\"" line)))
>               (if m (match:substring m 1)
>                   (loop (read-line in 'concat)))))))))
> #+end_src

Sounds reasonable to me.  If I understand the toml format correctly,
“name=.*” is guaranteed to be on a line on its own, so that looks safe.

> As you can see this is very minimal/naive (takes the first name = ""
> occurrence, does not even consider comments, for which I'd add a
> negative lookahead "^(?!#)" which I can't get to work with ice-9 regex),
> but tested on a few packages it working.  I don't know what to do when
> the match is not found (since it's something that might happen only
> during development, the #f fallback should not be too bad, btw, as the
> build will fail).

Yes, sounds good.

To be on the safe side, we can add a #:julia-package-name parameter to
the build system; it would default to #f, in which case the name is
extracted from the toml file.

> The other way I think this is easily solvable is by asking julia
> directly, by reading the output of:
>
> (invoke-julia "using Pkg; Pkg.TOML.parsefile("Project.toml")["name"] |> println")
>
> doing something like cargo's manifest-target procedure does.  But it'd
> go the other way if it's ok.

Yeah, the basic “parser” seems to be good enough.

Thanks!

Ludo’.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.