proposing changes to RRRS

[CPH%OZ.AI.MIT.EDU@XX.LCS.MIT.EDU]

    Date: Thursday, 20 February 1986  19:58-EST
    From: willc%tekchips%tektronix.csnet at CSNET-RELAY.ARPA

    Controversial changes

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    Page 17:  I'd still like to see named-lambda removed from the language
    definition.  Any implementation capable of handling
    (named-lambda (var ...) ...) specially should be capable of handling
    (rec var (lambda (...) ...)) specially.

I agree, despite the fact that I invented this one in MIT Scheme (I
wish I hadn't, this special form proliferation is driving me nuts!)  I
would go one step farther, in proposing to flush REC as well, since
such an implementation could also handle the special case of LETREC
just as easily (however, I bet there are folks out there, unlike me,
who use REC all the time.)

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    Page 19:  In talking about do, RRRS says that "the results of the step
    expressions are stored in the bindings of the vars".  I would rather change
    the semantics so that the step expressions are evaluated, the vars are
    bound to fresh locations, and the results of the step expressions are
    stored into those locations.

    The proposed semantics is the one that has been used in Scheme up until
    the RRRS.  MacScheme and T3 still use it in violation of RRRS; others
    may also.

Yes!  I never even looked at it closely enough to notice that the MIT
Scheme implementation also uses the proposed semantics rather than the
RRRS semantics.