[plt-scheme] Re: [Larceny-users] side effects in R6RS modules

From: namekuseijin (namekuseijin at gmail.com)
Date: Tue May 5 11:35:58 EDT 2009

Speaking of RNRSs unspecified behaviours I always wished to modify:

(set! foo bar)
(sequence-set! foo index val)

to return the value of the variable being set.  Come on, I know you
folks wish it too... :P

On Tue, May 5, 2009 at 12:21 PM, Abdulaziz Ghuloum <aghuloum at gmail.com> wrote:
> On May 5, 2009, at 5:44 PM, Matthias Felleisen wrote:
>> In PL, such questions should be decided via mathematical models that
>> do not depend on machines and compilers. That's the only way to truly
>> disambiguate the English in a spec.
>> For whatever reasons, the editors moved the only piece of mathematics
>> semantics (which doesn't include modules and macros) to the appendix,
>> for reasons that still escape me. Well, they don't really. If you
>> don't have a tool for arbitrating two distinct interpretations of
>> an informal document, you can always claim that both are correct and
>> if you so desire, you can claim one of them is, eh, smart? :-)
> Such tool helps indeed, but it's not the only way to arbitrate
> the different interpretations of the document.  As a matter of
> fact, the document in question explicitly states that both of
> these interpretations (and many others) are allowed and are
> correct with regard to satisfying the report's requirements.
> The issue here is that the library in question has nonportable
> semantics (as should be clear from reading the document) but
> this is the same as depending on any other unspecified behavior
> (such as one implementation's evaluation order: left-to-right,
> right-to-left, ...).  You're not arguing that there must be
> only one valid and true interpretation of the report, right?
> Aziz,,,
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