[TUHS] [rick@rbsmith.com: Re: SCCS roach motel]

[TUHS] [rick@rbsmith.com: Re: SCCS roach motel]

[Larry McVoy]

----- Forwarded message from Rick Smith <rick@rbsmith.com> -----

Date: Fri, 13 Dec 2024 18:22:29 -0500
From: Rick Smith <rick@rbsmith.com>
To: Larry McVoy <lm@mcvoy.com>
Subject: Re: [TUHS] SCCS roach motel
X-Mailer: Apple Mail (2.3826.300.87.4.3)

Hi Larry,

I likely can???t post to TUHS without joining, though I can read it fine.
Anyway, feel free to edit and post:

Marc,

I remember in 1992 driving to the UCSD library to get that issue of TSE and
make make copy of the article.  I still have it and wrote about it on HN [1]. 

The link I posted at the end there is dead (wayback [2]).  It is a post
by J??rg Schilling about your post here on TUHS about SCCS.

Yes, we could get lost in the weeds about choice of control-A, lack of
merge bookkeeping and the corner cases with -i and -x when applying strict
order to a partial order when computing the graph-to-set but in the big
picture, the SCCS system is a huge contribution.  Congratulations on
writing one of the most influential papers in TSE's first decade!  
Certainly is that for me.

Aside, Larry wrote:
> ... He [Rick] did point out that my weave implementation was the only
> one written such that I could have N serial sets in my hand, and do one
> pass through the weave and get N different checked out files.  I don't
> think we ever used that but if we did it would be in smerge.c.

The original makepatch() uses it in sccs_getdiffs() which walks the weave
calling changestate() once to track weave structure and printstate() twice,
generating a diff in one pass.

While this is a hats off to Marc, there is also a hats off to Larry
for extending the SCCS work with TeamWare and Bitkeeper. I studied SCCS
(and other engines).
Larry built systems.

[1] https://news.ycombinator.com/item?id=26225001

[2] https://web.archive.org/web/20190403213137/http://sccs.sourceforge.net/sccs_invention.html

----- End forwarded message -----

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Larry McVoy           Retired to fishing          http://www.mcvoy.com/lm/boat