Re: use of attribute Pos

["Pat Rogers" <progers@NOclasswideSPAM.com>]

"Philippe Torres" <ptorres@laas.fr> wrote in message
news:39E583F7.A971C8DB@laas.fr...
<snip>
> OK. Thank you all for your answers.
> I understand the behaviour on a subtype of "constraint" attributes
are
> the sole to change compared to the base class.
> But now, i wonder why Alejandro's solution
> ----
> type Upper is new Character range 'A'..'Z' ;
> begin
> Put(Upper'Pos('A')) ;
> ---
> still manages to output 65 and not 0.
>
> Since a different type is introduced, how does Pos still refer to
> Character ?
> Should not 'new' have broken all "links" between the types Character
and
> Upper ?

Now things get a little bit more involved.  :-)   The terminology
invariably confuses people, so I won't be precise in that regard.
Let's just say that what you really have here is a subtype of a type
derived from Character.  Since it has a distinct name (Upper) it is a
distinct type, but it is still a constraint on Character.

Hope that helps, as opposed to making it worse!  :-)

---
Patrick Rogers                      Consulting and Training in:
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