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

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Tue May 5 12:23:14 EDT 2009

The argument is about unintentional ambiguous interpretations.

When editors of a language report intentionally add ambiguous  
interpretation, I think they reject some amount of portability, and  
that's the issue you'd bring up then if you were allowed to argue  
with them.

Though now that the steerers also become the steered, there will be  
just the one true view.

On May 5, 2009, at 11:21 AM, Abdulaziz Ghuloum 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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