The closest I came was when we went from a single namespace for all structure names to a namespace for each structure, and references that were checked using the pointer type of the structure pointer.
My code was a nightmare, and some of the old Unix code was at least a bad dream. I had to start out pretending to have a single namespace, but when I saw the use of an actual structure pointer I had
to do it the new way. As I recall when I saw something that would not have been legal with the old rules (for example, two different structures with the same element name but different offsets) then I threw
the switch and demanded the new way.
There were certainly system changes that were flash cut. For example, changing the file system format -- there was no attempt to allow both, which meant that the conversion program got one shot to get it right. And it didn't always manage that...
----- Original Message -----
To:"Steve Johnson" <firstname.lastname@example.org>
Cc:"The Eunuchs Hysterical Society" <email@example.com>
Sent:Mon, 29 Oct 2018 12:02:29 -0700
Subject:Re: [TUHS] Archaic yacc C grammar
We actually had a pretty good system for making changes like that. First, we would change
the compiler to accept both the old and the new. Then we would produce a warning
that on a particular date the old would no longer work. Then we made the old an error
and printed a message about how to fix it. Eventually, we just let it be a syntax error.
This process was applied many times on the way from typeless B to strongly typed C.
Was there ever a time when a change was desired that you couldn’t accept both
the old and the new?