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 E-mail: si...@golden.net phone: 519-745-1313 cell (text only; not frequently checked): 519-998-2684 == 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)