Issue COMPILER-LET-CONFUSION, v3

[Kim A. Barrett <IIM@ECLA.USC.EDU>]

> Date: Mon, 26 Dec 88 23:21:38 PST
> From: Jon L White <jonl@lucid.com>
> Subject: issue COMPILER-LET-CONFUSION, V3

>> re: I've made a case that it [COMPILER-LET] expresses a useful high level 
>>    concept and that it can be coherently implemented. . . . 

> And many of us don't buy that argument.

And some of us do.  I freely admit that COMPILER-LET is rarely used, and
probably even more rarely used correctly because it isn't well documented.  The
former is not, in itself, sufficient reason to remove it from the language.  I
think I've personally used it maybe twice.  In one of those instances,
replacing it with the proposed macrolet-style solution would involve sticking a
data structure into the expansion code as a quoted constant and depending on an
eq test to match it, which might not work in some implementations (re:
quote-may-copy).  Since there are problems with the documentation, fix that.
Talk about problems like the possibility of differences between implementations
which do a prepass and those which don't.  Cleanup and clarify.  But don't
flush it unless you have clearly demonstrated that it is in fact useless (and
the fact that some reasonably well informed people don't agree that it is
useless means that such demonstration has not occured).

To turn your own question around, do you really feel that the next version of
CL will be "absolutely unacceptable" if it DOES have COMPILER-LET in it?

kab
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