LET macro

[Daniel L. Weinreb <DLW at MIT-AI>]

In general, I like the Lisp Machine to be compatible with Maclisp.
However, this particular feature (destructing LET) is one that I'd
prefer not to put in.  The main reason is that it is ill-conceived; LET
is in the business of binding variables over a scope, not of parsing
list structure, and ading that functionality is as elegant as attaching
a bathtub to a bicycle just because someone might want to take a bath.
I belive that I am hardly the only person who feels this way; most of
the Lisp machine hackers I know seem to agree.  Furthermore, this is a
very new Maclisp feature, and "old programs" will not die in droves if
we leave it out.  I'd prefere to put in a DESTRUCTURE function or
special form for this purpose, and make it availible to Maclisp users
by putting it in LIBLSP, for people who either don't like destructuring
LET or want to be compatible or both.