Re: weird \s

[Steve Izma]

On Mon, Mar 30, 2020 at 10:53:23PM -0400, Doug McIlroy wrote:
> Subject: Re: weird \s
> 
> Did the author of groff steal the code from Bell Labs?  Or did
> he merely read the code and preserve the feature in a misguided
> nod to backward compatibility?  Did he find it by experiment?

My understanding of the development comes from people I knew at
Softquad Publishing Software in Toronto in the 1980s and early
90s. They licensed the source code for the troff suite (either
Kernighan's ditroff or else the Documenters' Workbench code) from
AT&T. Their manual, "Text Formatting: Technical Reference" gives
a short "Historical Perspective" and points out that for ditroff 
"Kernighan kept the input language and maintained compatibility
with the established pre-processors." Presumably that included
the behaviour of \s because that behaviour is described in this
technical manual as;

\sNN <- 0 or a number from 4 to 39
\s±N <- a number from 0 to 9

etc. The manual I have dates from 1988.

In the mid-90s I heard from David Slocombe, SoftQuad's chief
programmer, that James Clark consulted closely with SoftQuad
about the enhancements they made to the system. I used SoftQuad
troff for almost 15 years before switching over to groff, and it
was a pretty easy transition, even with the couple of thousand
lines of macro code I had written for books and journals
typesetting. The main loss in the transition was that no one has
implemented for groff the very sophisticated debugging trace
output that sqtroff provided. But groff has been significantly
enhanced since then.

Hope this fills in some historical gaps.

        -- Steve

-- 
Steve Izma
-
Home: 35 Locust St., Kitchener, Ontario, Canada  N2H 1W6
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==
I have always felt the necessity to verify what to many seemed a
simple multiplication table.
        -- Ilya Ehrenburg (Soviet author and critic; he's not
           talking about mathematics)