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From: hansen@pegasus.att.com (Tony L. Hansen)
Newsgroups: comp.lang.c++
Subject: Re: A question about the use of "rep" in class names
Summary: "rep" == "representation"
Keywords: rep, classes
Message-ID: <1991May2.205519.9982@cbnewsk.att.com>
Date: 2 May 91 20:55:19 GMT
References: <2239@qtc.UUCP>
Sender: hansen@cbnewsk.att.com (tony.l.hansen)
Distribution: usa
Organization: AT&T Bell Laboratories
Lines: 29

< From: stevew@qtc.UUCP (Steve Weston)
<
< I have a question that has been nagging me for some time.  Several
< books on C++ ("Programming in C++" by Dewhurst and Stark, and "The C++
< Answer Book" by Tony Hanson) make use of classes with "rep" in the name
< for implementing reference counting schemes.  Dewhurst and Stark have a
< String_rep class, and Hanson has vrep and mrep classes for vector and
< matrix classes.  Is the similar terminology a coincidence, or does it
< come from some language, such as Lisp, or some classic work, such as
< Knuth?  What does "rep" mean, and what is its history?

While I can't speak for Steve Dewhurst and Kathy Stark, I think I can answer
for the usage in my book. From my perspective:

	"rep" == "representation"

For example, the String class provides the external interface and the
String_rep class provides the true representation of the class itself. For
private classes such as these (nested classes which are intended to be used
only by the enclosing class), "rep" seems as good a qualifier as anything
else. I know that Bjarne Stroustrup also uses the qualifier "srep" in his
sample string class from his "The C++ Programming Language". I don't know
about other earlier uses of the same terminology.

					Tony Hansen
			    hansen@pegasus.att.com, tony@attmail.com
				att!pegasus!hansen, attmail!tony

P.S. It's "Hansen", not "Hanson". :-)