[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Printing dotted pairs with AND and OR
Date: Thu, 11 Feb 88 12:06:57 CST
From: Daniel A Haug <aihaug@AUSTIN.LOCKHEED.COM>
Check this out:
--> '(and . foo)
#<error printing object CONS nnnnnn>
The problem is that AND and OR have a property GPRINT::FORMATTER that
specifies GPRINT::FORMAT-AND-OR as the format function. Looking at the
source for this function reveals a call to LENGTH on the output form,
for which a dotted pair causes great grief.
I can hack a fix to this, but I'm not much of a systems person when it
comes to making system-type fixes. Can anyone suggest a fix to me?
Wonder if this is fixed in 7.2?
It is fixed in 7.2. Try this for a workaround. I haven't verified that
this code will run in 7.1, but it looks trivial.
;;; -*- Mode: LISP; Package: GPrint; Syntax: Common-Lisp; Lowercase: Yes -*-
;;; AND and OR: Stack vertically unless only two long and
;;; one or the other is an atom or the second is a GO.
(defun format-and-or (x)
(cond ((cdr (last x))
((and (= (length x) 3)
(simple-p (second x))
(simple-p (third x)))
(gformat "(*_<*!>)" x))))