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Re: specification by implications and example

This page is part of the web mail archives of SRFI 17 from before July 7th, 2015. The new archives for SRFI 17 contain all messages, not just those from before July 7th, 2015.

Matthias Felleisen <matthias@xxxxxxxxxxx> writes:

> In this specific case, I think we would like to see something like 
>     "
>      (set! exp exp)			  expression 
>      The lhs is evaluated with a left-hand side
>      evaluator. If the evaluation does not yield a
>      reference, an error is signaled. If it does,
>      the reference is modified. 
>     "
> if this is what you intend. As of now, I am sorry, but I simply don't
> understand the proposal. 

No, this is not my proposal.  I agree that would require more serious
specification, specifically of the new concerpts "left-hand side
evaluator" and "reference".  That might be an interesting extension
to Scheme, but it is not this proposal.  (I have in Kawa implemented
a "location" concept which is like a first-class reference.  I even
mentioned that as a possible future SRFI in my first draft, but the
editors convinced me to leave it out to avoid confusion ...)
	--Per Bothner
per@xxxxxxxxxxx   http://www.bothner.com/~per/