[Asdf-devel] :AROUND methods

[Faré]

On Sat, Jun 7, 2014 at 4:02 PM, Robert P. Goldman <rpgoldman at sift.info> wrote:
> I was wondering about the :AROUND methods for OUTPUT-FILES and
> INPUT-FILES, which are exported and which we invite programmers to
> provide methods for.
>
> I don't think this is necessarily a big deal: we explain pretty
> carefully the contract for these functions (I need to check on the
> discussion in the manual).  But we *could* add a wrapper function around
> OUTPUT-FILES (resp. INPUT-FILES) and put the :AROUND logic in that, and
> have ASDF internally call the wrapper function instead of OUTPUT-FILES
> (resp. INPUT-FILES).
>
> Would this be a worthwhile clean-up?
>
But we don't invite programmers to redefine methods for existing classes,
or at their own risk.

Why would these particular functions be special and require that
there be a blank slate for :around methods?

If any actual programmer comes up with a need for more extension points,
*then* extension points can be provided.

In addition to the perform-with-restarts issue, the development of
ASDF2 and ASDF3 already led to defining plenty of new extension points
so that the various extensions used at ITA (most notably POIU and
ASDF-DEPENDENCY-GROVEL) could be written without overriding ASDF
internals. The advantage of letting actual clients drive the
definition of extension points is that you then know that your
extension points make sense and have at least one client that'll test
the functionality.

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