[asdf-devel] Feature-conditional components

[Nikodemus Siivola]

On 22 October 2010 05:19, Faré <fahree at gmail.com> wrote:

> 2- the feature feature was never working before I fixed and cerror'ed
> it, and only does conditional *dependency* on another component, that
> has to independently exist or conditionally exist, for which we have
> no non-ugly mechanism.

> 3- the :if-component-dep-fails mechanism may or may not be working
> well enough to do that right now, but man it's ugly, non-intuitive,
> non-documented, and gross even if it were documented.

Note: I have two different use cases.

One is a DEFSYSTEM -level :DEPENDS-on ((FEATURE :SBCL :SB-THREAD)) or
similar to indicate what *FEATURES* the system assumes, so that tools
like Quicklisp could use this information to good effect.

It should be checked during attempts to OPERATE LOAD-OP on system,
with an error if the feature is not present, and it should be
available through system introspection.

The thing that I'm currently using :IF-COMPONENT-DEP-FAILS :TRY-NEXT
for currently is

  (:FILE "sbcl" :IN-ORDER-TO ((COMPILE-OP (FEATURE :SBCL))))

which is quite different.

Cheers,

 -- Nikodemus