Re: ADA Popularity Discussion Request

[Jean-Pierre Rosen <rosen@adalog.fr>]

Kevin Cline a écrit :

> I seem to have confused limited types and controlled types, probably
> because I stopped programming in Ada before there were controlled
> types.  Still, using controlled types also seems to be problematical. 
> For example, I found this at http://www.gidenstam.org/Ada/:
> 
> "In Ada controlled types, i.e. types with user defined initialize and
> finalize operations, must be declared at the library level - either as
> direct descendents of Ada.Finalization./Limited_/Controlled or via a
> mixin component that inherits from
> Ada.Finalization./Limited_/Controlled. This makes it a bit of a hassel
> to use controlled types, and in particular it makes it quite limiting
> to use controlled types in generic packages that one otherwise would
> have liked to instansiate at other levels than the library level.
> [...] 
> I don't know about you, but that mades my head hurt.  In C++ there are
> some things that make my head hurt too, but they mostly are there to
> determine the meaning of code that I would naver write in the first
> place.
It is true that controlled *types* (not objects) need to be declared at 
library level. However, all other OO languages (that I know of) require 
*all* classes to be declared at library level.
So, there is no reason to have your head hurt. It's just one of the few 
cases where Ada makes even with other programming languages, not better.
-- 
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            J-P. Rosen (rosen@adalog.fr)
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