Re: loop indices

[eachus@mitre-bedford.arpa (Robert I. Eachus)]

In article <1992Apr21.211509.1911@software.org> smithd@software.org (Doug Smith
) writes:

   Then during an investigation encountered an interesting problem.
   Guess where the following code encounters a constraint error:

   <example deleted...>

   No, this is not a solution--but look carefully at the variable
   v3:
       It is of subtype Vec which is a constrained array
	  with range 21..25
       v3'range is   51..55.

   Have I missed something?  (This compiles using Verdix and Dec
   Ada compilers).  Any comments from the Language Lawyers?

   RFTM 8.5(4) :-) ...The renamed entity must be an object of the base
type of the type mark.  The properties of the renamed object are not
affected by the renaming declaration.  In particular, its value and
whether or not it is a constant are unaffected; similarly, the
constraints that apply to an object are not affected by a renaming
(any constraint implied by the renaming declaration is ignored....

    Surprising, true.  But you really have to work at it to get bitten
by this rule.  (In the more frequent case where both type marks are
the same--and unconstrained--you don't want implicit sliding of the
bounds.  Having the bounds slide in some cases and not in others would
really be perverse.)


					Robert I. Eachus

with STANDARD_DISCLAIMER;
use  STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...
--

					Robert I. Eachus

with STANDARD_DISCLAIMER;
use  STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...