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Re: duplicate names in LET*
Date: 25 Jul 86 00:30 EDT
To: "Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>
Subject: duplicate names in LET*
The rule in Common Lisp should be that you can't have duplicate names in
the same LEXICAL ENVIRONMENT. This rules out duplicate names in a lambda
list or a LET, and duplicate tags in a tagbody. But it should not rule
out duplicate names in a LET* because the variables in a LET* are bound in
different lexical environments. ...
Wait a second. The optional and keyword parameters are NOT in the
same lexical environment, they are in nested ones, e.g.,
((lambda (&optional (v1 e1) (v2 e2) (v3 e3)) body))
is semantically equivalent to
(let* ((v1 e1) (v2 e2) (v3 e3))
So why should lamda-lists be treated differently than LET*?