[plt-scheme] Help with #0 and #0# notation in the REPL

From: Robby Findler (robby at cs.uchicago.edu)
Date: Tue Jan 29 07:35:12 EST 2008

On Jan 29, 2008 5:22 AM, Jens Axel Soegaard <jensaxel at soegaard.net> wrote:
> Robby Findler wrote:
>  >> Why was this change made?
>  >
>  > It simplifies the compiler and tools that operate on program source if
>  > there are no cycles in what they have to process (it isn't a normal
>  > thing to think about that a program's AST is cyclic!) and so we
>  > decided to experiment with leaving it out.
> Besides syntactically recursive programs doesn't give you more
> expressive power. What I am talking about?
> <http://pagesperso-systeme.lip6.fr/Christian.Queinnec/Papers/synrec.ps.gz>
> [Yes, slightly off-topic but close enough ;-) ]

FWIW, mzscheme never worked for such programs. It would fail to
terminate while compiling them. It only ever worked for quoted cyclic
data (and that's what's gone now).


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