Ripple effect

["Jeffrey R. Carter" <spam.not.jrcarter@acm.not.spam.org>]

On the Ada-Comment mailing list recently, Robert Duff shared some ideas 
on language design for a language he is thinking about (which may be 
called Nada, but is definitely not called Duff). In this language, there 
is no equivalent of the Ada "use" and primitive operators ("+", "-") of 
a type are directly visible wherever the type is used.

I recall that during the Ada-9X revision process, it was proposed that 
primitive operators of a type have this kind of visibility. IIRC, one of 
the reasons that this was not accepted was that it would lead to Ripple 
effects: adding or removing a unit from a context clause could change 
one legal program to a different legal program.

If Herr Doktor Professor Duff is interested, I'd like to hear his 
thoughts on the matter, and how Nada (or whatever) deals with this.

-- 
Jeff Carter
"Brave Sir Robin ran away."
Monty Python and the Holy Grail
59