Re: There are things that don't evolve

Jim
  Yes everything evolved.
-input language features
-machine instructions (even on the much reviled "clunky mainframe",
there were huge changes that broke things)
-customer requirements and needs
-object formats
-architecture (within major sections and even the intermediate language
interfaces)
...

In general we built major interfaces that separated concerns of
different parts of the compiler. We tried very hard to preserve these
interfaces, even to the point of having transition mapping code in and
out. Preserving interfaces was especially important around the
optimizer since the investment in it was in the 100s of millions
involving teams in Toronto as well as people Randy Isaac managed in
Yorktown. As lead architect that was one of my key ongoing concerns.

We tried to intelligently design things and often succeeded but
sometimes our designs were unintelligent.

As one works at these kinds of large bodies of programming code, one
learns a great deal about the problem and what works and what does not
work. Very often I wished I knew earlier what I learned after a few or
many years of experience. In this sense our thinking evolved. Some
interfaces were cast in concrete and unchangeable or at least I and
others agonized long and hard before changing them as a change often
cost lots of dollars as well as time in the marketplace.

Probably we should take further discussion off line unless none
programmers think this is relevant.

Dave Wallace

Jim Armstrong wrote:
> But didn't you also find that the architecture of the code also
> evolved, ...e.g., modular structures, in order to make the coding more
> robust, efficient, and easy to revise without unintended consequence?
> And didn't you find that certain aspects or blocks of the code were
> preserved because they worked particularly well, enough to be
> propagated into succeeding generations? These seem to me to be both
> evolutionary and entropic parallels as well. JimA
>
> Bill Hamilton wrote:
>>
Received on Tue Apr 4 15:21:13 2006