Re: Ada development environments

[Simon Wright <simon.j.wright@amsjv.com>]

john@assen.demon.co.uk.nospam (John McCabe) writes:

> PS - If you get a new release of Apex, check out whether the bug
> related to the discriminant of a private extension is corrected:
> 
> type X (Disc : <sometype>) is tagged record with
>    :
>    :
> end record;
> 
> type Y (Disc : <sometype>) is new X (Disc) with private;
> 
> (I think this is the basis of it) This is illegal but is compiled
> without error on (what I believe is) the current version of Apex.
> Unfortunately it is also a bug in Rose because Rose generates code
> that matches this :-(

ObjectAda 7.2 accepts this too:

package Mccabe is
  type X (D : Boolean) is tagged null record;
  type Y (D : Boolean) is new X (D) with private;
private
  type Y (D : Boolean) is new X (D) with null record;
end Mccabe;

(hope you don't mind my taking your name in vain)

whereas GNAT 3.13p says

mccabe.ads:3:31: Only static constraints allowed for parent discriminants in the partial view

A look at the AARM tells me I'm going to find this tough. Is there a
plain-language discussion? (eg, a hint on how I can achieve the intent
of the above) I failed to find anything via deja ..

-- 
Simon Wright                         Email: simon.j.wright@amsjv.com
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