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

Despite the remarks of Grant Rettke,
I would not mind loosing `(rnrs mutable-pairs)'
assuming that
1: all PLT's R6RS lists will be immutable PLT Scheme lists.
2: PLT's R6RS would allow to import mpair, mcar, etc and all of 
`scheme/mpair'.

Jos

----- Original Message ----- 
From: "Matthew Flatt" <mflatt at cs.utah.edu>
To: "Grant Rettke" <grettke at acm.org>
Cc: "Abdulaziz Ghuloum" <aghuloum at cs.indiana.edu>; "PLT List" 
<plt-scheme at list.cs.brown.edu>
Sent: Wednesday, November 26, 2008 3:49 PM
Subject: Re: [plt-scheme] Mutable and immutable pairs in PLT Scheme


> At Wed, 26 Nov 2008 08:35:57 -0600, "Grant Rettke" wrote:
>> On Wed, Nov 26, 2008 at 7:57 AM, Matthew Flatt <mflatt at cs.utah.edu> 
>> wrote:
>> > At Tue, 25 Nov 2008 23:28:16 -0500, Abdulaziz Ghuloum wrote:
>> >> 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.
>> >
>> > I imagined that users would be too unhappy with that level of
>> > non-conformance, but it sounds like I may have been wrong.
>> >
>> > Does anyone here want PLT Scheme's R6RS support to include `(rnrs
>> > mutable-pairs)'?
>>
>> Yes.
>>
>> While I can't claim any Scheme implementation (#3) or programming
>> language design experience (#2) when it comes to this topic, it does
>> seem pretty clear to me that taking this step would create a marketing
>> nightmare for PLT.
>
> Well, the Scheme community being what it is, most any significant
> action creates PR and diplomacy problems. We can deal with them,
> though, if the action is otherwise useful enough.
>
> So, to help gauge usefulness for this potential action, I'll revise the
> question:
>
> Does anyone actually use (and expect to continue to use) the `(rnrs
> mutable-pairs)' library in PLT Scheme's R6RS?
>
>
> Thanks,
> Matthew
>
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