Actually if I'm going to be defining my own macro, I usually just do
(define-syntax carn (syntax-rules () ((_ n e) (let ((p e)) (if (pair?
p) (car p) (error 'n "not a pair" p))))))
and pass an identifier to carn... and then I can get rid of the check
by adding another line to the macro... but it doesn't look as nice as
just using car

On Thu, Apr 30, 2009 at 3:35 AM, Abdulaziz Ghuloum <[email protected]> wrote:
>
> On Apr 29, 2009, at 4:35 PM, Ramana Kumar wrote:
>
>> is the number of kinds of situtation where source file information
>> will be attached to errors such as car's "not a pair" likely to
>> increase?
>
> Yes, but I don't know when.  In the meanwhile, you can cook a 95%
> solution yourself by defining your own "car" as a macro.  Do you
> know how?  Any takers for the challenge?
>
> Aziz,,,
>

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