[no subject]

[Fahlman at CMU-20C]

It seems clear to me that we MUST support two kinds of binding forms: a
simple-syntax form as in PROG and LET, and a more complex form as in
DEFUN and LAMBDA.  (Not to mention odd things like DO and PROGV that are
different but necessary.)  It clearly makes no sense to hair up PROG and
LET with optionals and rest args, since there is no possible use for
these things -- they would just confuse people and be a pain to
implement.  It is also clear that we are not going to abandon optionals
and rest args in DEFUN and LAMBDA in the name of uniformity -- they are
too big a win when you are defining functions that are going to be
called from a lot of different places, not all of them necessarily known
at compile-time.  So I don't really see what RPG is arguing for.  The
issue is not whether to support both a simple and a hairy syntax for
binding forms; the issue is simply which of these we want the
MV-catching forms to be.  And in answering that question, as in many
other places in the language, we must consider not only uniformity as
seen by Lisp theologians, but also implementation cost, runtime
efficiency, and what will be least confusing to the typical user.

-- Scott
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