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DECLARE SPECIAL Considered Confusing
- To: RWK@SCRC-YUKON.ARPA
- Subject: DECLARE SPECIAL Considered Confusing
- From: Jonathan A Rees <JAR@AI.AI.MIT.EDU>
- Date: Mon, 14 Jul 86 18:00:13 EDT
- Cc: Common-Lisp@SU-AI.ARPA, Pavel.pa@XEROX.COM, Moon@SCRC-STONY-BROOK.ARPA
- In-reply-to: Msg of Mon 14 Jul 86 16:46 EDT from Robert W. Kerns <RWK at YUKON.SCRC.Symbolics.COM>
Date: Mon, 14 Jul 86 16:46 EDT
From: Robert W. Kerns <RWK at YUKON.SCRC.Symbolics.COM>
Date: 11 Jul 86 18:43 PDT
There are six primitive forms in Common Lisp that can both bind
identifiers and carry declarations:
LET LET* FLET LABELS MACROLET LAMBDA
I will describe the scoping rules for declarations in each of these
You forgot DEFUN and DEFMACRO (and similar top-level definers).
Those, I believe, would be unchanged by your proposal, no?
Pavel was only talking about the -primitive- forms. DEFUN and DEFMACRO
are macros. Presumably DEFUN has the obvious expansion in terms of
LAMBDA, so that it follows the same rules as LAMBDA (which I think
should be analogous to LET*, following the easy-to-remember principle
that the scope of a declaration of something bound by an expression is
the same as the scope of the binding itself). DEFMACRO, also
presumably, has a somewhat more complicated expansion, but would also
adhere to the principle.
Technically speaking, the proposal (with this amendment about the
meaning of LAMBDA as per a later message from Pavel, I think) consitutes
a change in the *meaning* of DEFUN and DEFMACRO, although probably not
in its implementation in terms of LAMBDA. In any case DEFUN should be
consistent with LAMBDA.