Subject: Re: Deep copy in lisp: how?
From: (Rob Warnock)
Date: 2000/04/10
Newsgroups: comp.lang.lisp
Message-ID: <8cr9tm$1scu2$>
Erik Naggum  <> wrote:
| * Courageous <>
| | I know this is possible one way or the other, for I have seen automatic
| | deep copy implemented via code generation in C++.
|   I'm sorry, but you have been tricked.  just because it exists for C++ is
|   not in any way, shape, or form an argument for the _correctness_ of the
|   implementation or the algorithm or even the concept to begin with.

Indeed. Perhaps it's time once again to drag out Kent Pitman's classic
"Parenthetically Speaking" article on the subject:

	The Best of Intentions: EQUAL Rights--and Wrongs--in Lisp

which addresses the question "Why is there no generic COPY function?"
[in Common Lisp], and explains why any so-called "automatic" deep copy
is inherently *wrong*.


Rob Warnock, 41L-955
Applied Networking
Silicon Graphics, Inc.		Phone: 650-933-1673
1600 Amphitheatre Pkwy.		PP-ASEL-IA
Mountain View, CA  94043