[asdf-devel] Status of :feature

Faré fahree at gmail.com
Wed Mar 23 14:18:45 UTC 2011

On 23 March 2011 09:49, Didier Verna <didier at lrde.epita.fr> wrote:
> what is the current status of :feature in a list of dependencies? I
> mean, is it safe to replace #+ reader conditionals in the asd file with
> it?
It's complex and underpowered, and underdocumented. Some report
getting it to work, others report failing to make it work. We're
trying to support existing practice, but I'm not sure we encourage it
at this point. You're welcome to document it after you get it to work.

[Removing my hat of ASDF maintainer]
Personally, I prefer the XCVB way of doing things:
* having a module bar under build foo doesn't necessarily mean that
 building foo depends on bar - just that you can name and find bar under foo.
* build foo starts includes a list of direct dependencies;
 other dependencies are found recursively
* the dependency language has conditionals, and a sublanguage for features,
 so you may depend on
  (:when (:featurep :sbcl) "cmu-descendant-addon1" "sbcl-addon2")

Note that this goes contrary to the current ASDF design, so it's not trivial
to import ideas from XCVB into ASDF.

The good news is that XCVB works, and that it's easy to mix and match
between ASDF and XCVB. The bad news is that it currently only
supports three implementations, on Unix only, so isn't ready
to supplant ASDF yet.

[ François-René ÐVB Rideau | Reflection&Cybernethics | http://fare.tunes.org ]
Obscenity is the crutch of inarticulate motherfuckers.

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