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Re: quoted data in macro expansion
Per Bothner wrote:
> Am I correct in understanding that any quoted S-expressions, in either a
> macro "parameter" or in a template, is copied?
> I don't know if this is a big deal, but it breaks pair identity in cases
> where it is preserved in existing implementations. This seems to make
> SRFI-72 essentially incompatible with SRFI-38, in the sense that you
> can't use of SRFI-38 shared structure in programs (though it is still
> available for external data). And of course cycles are prohibited.
Good point. I assume you mean expressions like
(define ones (quote #0=(1 . #0#)))
The procedures that would have to be changed to support this are the
current implementations of datum->syntax and syntax->datum, essentially
lifting the algorithm of SRFI-38 in the way you suggest.