Re: [Sbcl-devel] named-lambda

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

On 9/7/07, Nick Allen <nal...@gm...> wrote:

> What are the chances of  SB-EXT::NAMED-LAMBDA ever turning into
> SB-EXT:NAMED-LAMBDA? opinions? comments?

Weak, I think. What's wrong with the portable version? (Only difference
is that ((named-lambda foo (x) ...) ...) is not legal with the portable
version, but the benefit is that code walkers don't need to treat is
specially.)

(defmacro named-lambda (name lambda-list &body body)
  `(labels ((,name ,lambda-list ,@body))
     #',name))

(funcall (named-lambda foo (x) (if (zerop x) x (/ x (foo (- x 1))))) 3)

->

arithmetic error DIVISION-BY-ZERO signalled
Operation was SB-KERNEL::DIVISION, operands (1 0).
   [Condition of type DIVISION-BY-ZERO]

Restarts:
 0: [ABORT] Return to SLIME's top level.
 1: [TERMINATE-THREAD] Terminate this thread (#<THREAD "repl-thread" {B374961}>)

Backtrace:
  0: (SB-KERNEL::INTEGER-/-INTEGER 1 0)
  1: ((LABELS FOO) 1)
  2: ((LABELS FOO) 2)
  3: ((LABELS FOO) 3)
  4: ((LABELS FOO) 3)

Cheers,

 -- Nikodemus