Re: [Scheme-reports] Write procedure is not backwards compatible
John Cowan 02 Jul 2012 00:22 UTC
Marc Feeley scripsit:
> R7RS introduces a new output procedure called write-simple, which has
> the same semantics as the R5RS write procedure. On the other hand,
> the R7RS write procedure handles shared structures differently than
> the R5RS. For example :
>
> (let ((x (list 1 2))) (write (list x x)))
>
> displays ((1 2) (1 2)) in an R5RS system
> and displays (#0=(1 2) #0#) in an R7RS system
R5RS leaves the output of `write` unspecified in such a case. In actual
fact, it leaves the output of `(write (list 1 2))` unspecified as well.
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