[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

(setf (not x) y) => (setf x (not y))

To: DCP@QUABBIN.SCRC.Symbolics.COM, Fahlman@C.CS.CMU.EDU
Subject: (setf (not x) y) => (setf x (not y))
From: Guy Steele <gls@Think.COM>
Date: Tue, 22 Jul 86 12:54 EDT
Cc: common-lisp@SU-AI.ARPA, gls@AQUINAS
In-reply-to: <860720154642.7.DCP@FIREBIRD.SCRC.Symbolics.COM>

Fine.  I don't see any reason why a user shouldn't be allowed
to do a DEFSETF of NOT.  I am not crazy about installing it as
a requirement in the language.  Years ago I sent out examples
involving * and SQRT, looking something like this:

	(setf (sqrt x) y) -> (setq x (* y y))
	(setf (* x y) z) -> (setq x (/ z y))
	(setf (* x x) z) -> (setq x (sqrt z))


We could do it, but it would be wrong.

--Guy

Follow-Ups:
- (setf (not x) y) => (setf x (not y))
  - From: David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>
- (setf (not x) y) => (setf x (not y))
  - From: David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>

References:
- (setf (not x) y) => (setf x (not y))
  - From: David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>

Prev by Date: The Noncontroversial Ten Proposals
Next by Date: (setf (not x) y) => (setf x (not y))
Previous by thread: (setf (not x) y) => (setf x (not y))
Next by thread: (setf (not x) y) => (setf x (not y))
Index(es):
- Date
- Thread