[plt-scheme] Mutable and immutable pairs in PLT Scheme

From: Abdulaziz Ghuloum (aghuloum at cs.indiana.edu)
Date: Tue Nov 25 23:28:16 EST 2008

On Nov 25, 2008, at 10:53 PM, Thomas Chust wrote:

> But I also agree that mutable lists are rarely ever useful. I would  
> even
> be happy with the extreme way to solve the interoperability problem:
> Simply switch all the dialects of PLT Scheme to immutable pairs. Even
> though it's a deviation from the standards, it would probably be less
> problematic than the current situation and it would certainly allow  
> the
> collection of experience for the future ;-)

This is what I'd thought would happen; ditch the (rnrs mutable-pairs)
library for the sake of (1) more interoperability with the PLT modules,
(2) more encouragement for people, even outside of PLT, to get rid of
set-car! and set-cdr! in their code (which should be easy according to
Matthews's blog), and (3) going through less hassle implementing what
is effectively a parallel universe just for mutable pairs.

So, I was surprised when I saw that Matthew picked interoperability
with code that uses set-car!/set-cdr! (very little importance IMHO)
over interoperability with the rest of the PLT code base.


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