Re: [Sbcl-help] (declare (values variable)) in sbcl?

[Nikodemus S. <nik...@ra...>]

Karsten Poeck <kar...@gm...> writes:

> I am trying to compile cl-http in sbcl.
> The biggest problem I currently have is that cl-http is full of code like
>
> (defun foo (bar)
>      (declare (values bar))
>     ...)
>
> Since the declare values seem to be lispm-specific, I added a
> (declaim (declaration values)) to the code and in other lisps I have 
> no problem (some package lock errors, but this is not blocking).

Actually, SBCL supports the (non-portable, possibly non-conforming)
VALUES declaration just as well as CMUCL: no need for the declaration.

> However in sbcl, even after confirming the package-unlock, code like 
> the above will compile with a warning that the type bar is not defined
> and at runtime I get a unknown type error.

A values declaration like in your example requires that type BAR
is defined.

> There are hundreds of (declare (values ..)) in the codebase and I 
> cannot change them all.

That would really be my preferred solution, though. The effect of a
values declaration can be portably had with an FTYPE declamation:

 (declaim (ftype (function (bar) (values bar &optional))) foo)

Cheers,

  -- Nikodemus              Schemer: "Buddha is small, clean, and serious."
                   Lispnik: "Buddha is big, has hairy armpits, and laughs."