On Tue, Aug 31 2021, Maxime Devos wrote:

> Sarah Morgensen schreef op di 31-08-2021 om 12:57 [-0700]:
>> Hello Guix,
>> 
>> Currently, there are about 1500 packages defined like this:
>> 
>> --8<---------------cut here---------------start------------->8---
>> (define-public sbcl-feeder
>>   (let ((commit "b05f517d7729564575cc809e086c262646a94d34")
>>         (revision "1"))
>>     (package
>>       [...])))
>> --8<---------------cut here---------------end--------------->8---
>> 
>> I feel like there are some issues with this idiom (in no particular
>> order):
>> 
>> 1. When converting between this idiom and regularly versioned packages,
>> the git diff shows the whole package changing because of the indentation
>> change.
>> 
>> 2. We cannot get at the source location for the definition of 'commit' or
>> 'revision'.  This would be useful for updating these packages with `guix
>> refresh -u`.  There is a proposed patch [0] to work around this, but it
>> *is* a workaround.
>> 
>> 3. Packages inheriting from it lose the definitions.  For actual fields,
>> we have e.g. `(package-version this-package)`, but we have no equivalent
>> for these.
>> 
>> 4. Horizontal space is at a premium, and an extra two spaces here and
>> there add up.  (Personally, I think we could do with a
>> define-public-package macro to save another two spaces, but that's for
>> another day...)
>> 
>> 5. The closest thing we have to a standardized way of generating
>> versions for these packages is `(version (git-version "0.0.0" revision
>> commit))`.  We can do better than that boilerplate.
>
> Suggestion: extend the 'version' field.  More specifically,
> introduce a new record <full-version>, like this:
>
> (define-record-type* <extended-version> extended-version make-extended-version
>   extended-version? this-version
>   ;; something like 1.2.3 (TODO better name)
>   (base extended-version-base)
>   (revision extended-version-revision)
>   (commit extended-version-commit))
>
> (define (version->string version)
>   (match version
>     ((? string?) version)
>     (($ <extended-version> ...) code from original git-version  and hg-version)))
>
> ;; TODO:
> ;; adjust git-file-name and hg-file-name to accept <extended-version> records
> ;; (as well as the ‘old style’ for compatibility)
>
> To be used like:
>
> (define-public sbcl-feeder
>   (name "sbcl-feeder")
>   (version (extended-version
>              (base "1.0.0")
>              (revision 1)
>              (commit "b05f517d7729564575cc809e086c262646a94d34")))
>  (source
>   (origin
>     (method git-fetch)
>     (uri (git-reference ...)
>            (url ...)
>            ;; git-reference needs to be extended to retrieve the commit from the version
>            (version version)))
>     (file-name (git-file-name "feeder" version))
>     (sha256 ...)))
>  [...])

How will this work for SVN and CVS?  I am not familiar with either, but
I know that SVN has its own ‘revision’ thing.