Communicating between in and out contracts

[Rainer Deyke]

Rainer Deyke wrote:
> Andrei Alexandrescu wrote:
>> I honestly believe the whole "old" thing can't be made to work. Shall we
>> move on to other possibilities instead of expending every effort on
>> making this bear dance?
> 
> It definitely /can/ be made to work, for some value of "work".  It
> sacrifices the natural order of evaluation to gain a concise and
> intuitive syntax.  I don't think it should be dismissed out of hand.

Also, from the Eiffel docs
(http://archive.eiffel.com/doc/online/eiffel50/intro/language/invitation-07.html):
  The notation 'old  expression' is only valid in a routine
postcondition. It denotes the value the expression had on routine entry.

It seems that Eiffel had 'old' semantics that I've proposed all along.
Any significant problems with this approach would have been discovered
by the Eiffel community by now.


-- 
Rainer Deyke - rainerd at eldwood.com