[bug#50755] [PATCH v3] import: Generate list of importers based on available modules

[zimoun]

Hi,

On Mon, 27 Sept 2021 at 20:21, pinoaffe <pinoaffe@airmail.cc> wrote:

> +(define importers (delete-duplicates

This fixes my first point...

> +                   (filter-map (lambda (module)
> +                                 (match (module-name module)
> +                                   (`(guix scripts import ,importer)
> +                                    (symbol->string importer))
> +                                   ( #t #f)))
> +                               (all-modules (map (lambda (entry)
> +                                                   `(,entry . 
> "guix/scripts/import"))
> +                                                 %load-path)))))

...and it means it is walking more than needed.  Therefore, what is
the performance loss?

For instance, on my machine and hot cache, it is 4x slower.  And, this
readibility improvement is not worth, IMHO.
On cold cache, I do not have meaningful numbers because it requires to
run it several times and then compute an average.  What are the
numbers of your machine?

All the best,
simon