[asdf-devel] component-class for files selected on basis of *features*

I want to define a component class PORT-FILE, to be used like this: :components ((port-file "ccl" :when :ccl) (port-file "clisp" :when :clisp) (port-file "sbcl-x86" :when (and :sbcl :x86)) ...) The implementation I have adds AROUND methods for PERFORM (LOAD-OP PORT-FILE) PERFORM (LOAD-SOURCE-OP PORT-FILE) PERFORM (COMPILE-OP SOURCE-FILE) and does CALL-NEXT-METHOD only if the feature test passes -- which seems to work well enough, but is there a better place to hook into? Cheers,  -- Nikodemus