[comp.unix.questions] What became of QED

jones%cs.uiowa.edu@RELAY.CS.NET (Douglas Jones) (11/24/87)

As a long-time UNIX user who has used many of the predecessor systems on
which (or should I say from which) UNIX developed, I have noticed that
the ED editor (and descendants such as EX and brothers such as SED) have
not got the general regular expression facility of some of their predecessors.

In Ritchie and Thompson's version of QED, one could name a regular expression

  e(name)/expression/

and then use it in other expressions such as /regular \E(name)/ which would
match the string "regular expression".  I've recently written a grinder
for Pascal programs in LaTeX documents, and this would have made things easier
(the grinder is written in SED).

By way of history, QED was originally written by Deutsch and Lampson back
on the Berkeley Timesharing System (they published a CACM paper on it in
Dec. 1967).  Ken Thompson did a version of QED on MULTICS, (the tech report
came out before the Deutsch and Lampson's paper), and Ritchie and Thompson
did a version on the Murray Hill GCOS Timesharing System in 1970.  ED on UNIX
is a scaled back version of the GCOS QED editor, while SED puts back some of
the QED features that ED dropped, but abandons the possibility of interactive
use.  I've used QED on the Berkeley system in 1968, and on the Murray Hill
GCOS system in 1974.

Does anyone know why Ritchie and Thompson dropped the features they did when
they made QED into ED on UNIX?  If the reason was memory capacity, now that
most UNIX systems have capacity, why hasn't anyone put these features back
into text processing tools such as SED?

			Douglas W. Jones
			jones@cs.uiowa.edu (csnet)

gwyn@brl-smoke.ARPA (Doug Gwyn ) (11/24/87)

In article <10512@brl-adm.ARPA> jones%cs.uiowa.edu@RELAY.CS.NET (Douglas Jones) writes:
>Does anyone know why Ritchie and Thompson dropped the features they did when
>they made QED into ED on UNIX?  If the reason was memory capacity, now that
>most UNIX systems have capacity, why hasn't anyone put these features back
>into text processing tools such as SED?

So use "sam" (available from the AT&T UNIX System ToolChest in the dmd-pgmg
package); it has more support for regular expressions that "ed" and is nicer
in several other ways (even apart from its support for the DMD terminal).

dave@lsuc.UUCP (12/03/87)

jones%cs.uiowa.edu@RELAY.CS.NET (Douglas Jones) writes:
>By way of history, QED was originally written by Deutsch and Lampson back
>on the Berkeley Timesharing System (they published a CACM paper on it in
>Dec. 1967).  Ken Thompson did a version of QED on MULTICS, (the tech report
>came out before the Deutsch and Lampson's paper), and Ritchie and Thompson
>did a version on the Murray Hill GCOS Timesharing System in 1970.  ED on UNIX
>is a scaled back version of the GCOS QED editor...
>
>Does anyone know why Ritchie and Thompson dropped the features they did when
>they made QED into ED on UNIX?  If the reason was memory capacity, now that
>most UNIX systems have capacity, why hasn't anyone put these features back
>into text processing tools such as SED?

It's been said that ed retained 90% of the power of the original
qed while requiring only 10% of the complexity.  I think
that answers your question: it's consistent with the origins of UNIX.

A number of people, including me, use a qed derived from ed, however.
It's essentially a superset of ed, with a lot of *extremely* useful
features, the most notable of which is multiple buffers. (When
working with a large package, I "qed *.c" and buzz around between
the buffers making changes.)

This qed was extended from the U of Toronto v6 ed, originally by
Tom Duff, and then further reworked and extended by Rob Pike when
at Caltech and then Bell Labs.  (I now use a further enhanced
version by David Tilbrook, which includes in-line editing and
other neat features.)  Of course, editor preferences are
always religious matters, but I've always found qed to be
faster and more flexible than anything else around.  Its
string registers and other tools allow it to be used as a
(very cryptic) programming language, as well.

The Pike qed may be distributed to anyone with a UNIX source
license (required because it's still v6 ed down deep).
Quite a number of people with a Toronto connection use it.

David Sherman
The Law Society of Upper Canada
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