On Mon, Oct 29, 2018 at 12:30 PM Steve Johnson <scj@yaccman.com> wrote:

> 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.
>

How long a transition period did you typically have?

Warner