Re: [PATCH] Add CRAN importer.

[Thompson, David]

On Fri, Jul 24, 2015 at 11:07 AM, Ricardo Wurmus
<address@hidden> wrote:
> Hi Guix,
>
> attached is a patch to add a new importer for R packages published on
> CRAN.  (I still have to add tests for this.)
>
> The importer fetches the HTML description of an R package from
> http://cran.r-project.org, converts it to SXML, and then tries to
> extract the relevant information from the SXML expression.
>
> When I finished I thought that maybe this could be done with less effort
> by downloading the tarball from CRAN, extracting the plain text
> DESCRIPTION file containing the same information and parse that instead.
> But in order to get the tarball I’d have to parse the HTML anyway, so
> maybe that’s not so much better after all.
>
> This generates package expressions using the r-build-system — this build
> system does not yet exist, but I’ll prepare one soon, not least to test
> the importer.
>
[...]
> Without further ado: the patch.

It looks pretty good so far, IMO!

I don't have the time to a thorough review, but one thing I thought of
while perusing was that the regexp-substitute/global calls could be
factorized into procedures with descriptive names to aid the
readability of cran-sxml->sexp.

- Dave