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Re: specification by implications and example Per Bothner 17 Jan 2000 01:57 UTC

Matthias Felleisen <xxxxxx@cs.rice.edu> 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
xxxxxx@bothner.com   http://www.bothner.com/~per/