Re: Surprise in array concatenation

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Florian Weimer <fw@deneb.enyo.de> writes:

> * Dmitry A. Kazakov:
> 
> > A more interesting question is why Empty'First does not raise any
> > exception. After all, there is no any lower bound of an empty index range.
> > Provided, that empty arrays are all same, of course. If not, then another
> > interesting question would appear: how to make an empty array with the
> > lower bound Integer'First?
> 
> You can't.  Even more problematic is the empty array whose index type
> is an enumeration type with just one enumeration literal.

Why would you want an unconstrained array indexed by enumeration type?
And why would you want an empty array if the array type is constrained?

As for modular types -- well, they're an abomination all around.
It makes no sense whatsoever to have an index type for an unconstrained
array such that Index'Pred(Index'First) > Index'First!

- Bob