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Re: Problems with eval-when/shadowing-import
Roger Kehr <firstname.lastname@example.org> writes:
> I have encountered a small problem in conjunction with EVAL-WHEN and
> SHADOWING-IMPORT. The following source can be used to see what
> (shadowing-import 'language:data)
> (eval-when (compile load eval)
> (shadowing-import 'language:data))
Thanks for this easily reproducible test code. The issue is hairy:
* The form (shadowing-import 'language:data) is treated specially by
CLtL1 compilers, but -- as you noted -- in order to avoid magic in
the compilers, CLtL2 and ANSI CL decided that `shadowing-import'
isn't magic any more.
CLISP supports the old CLtL1 way of doing it.
* For the sake of these new compilers you wrap the form in a
(eval-when (compile load eval) ...).
CLISP, according to CLtL2's description of `eval-when', first evaluates
the form and then emits code for it. However, by doing the shadowing-import,
you changed the code that is emitted.
The code I propose is
(eval-when (load eval)
This way, CLISP will first emit the code and then modify its package