Re: "Beaujolais Effect" -- what is it?

[eachus@spectre.mitre.org (Robert I. Eachus)]

    I'll take a shot.  Jean Ichbiah offered a bottle of Beaujolais to
the first person to find an Ada 83 program where adding a use clause
chnged the meaning of the program without changing the legality.

    I think Bob Duff finally managed to contrive an example, but in
practice Beaujolais effects are not a problem in Ada 83.  Tucker and
company have devoted a lot of attention to minimizing them in Ada 9X
as well.

     There are many Beaujolais type effects in both Ada 83 and Ada 9X
that can occur if a with clause is added, but with clauses should be
expected to change things. For example, a procedure named in a with
clause will hide a procedure with the same profile made (potentially)
visible by a use clause.


					Robert I. Eachus

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--

					Robert I. Eachus

with Standard_Disclaimer;
use  Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...