Re: Lower bound of result of Ada.Strings.Unbounded.Slice

[Jeff Carter <jrcarter@acm.org>]

Randy Brukardt wrote:
> The correct AI to look at is AI-00238. It asks this exact question. You
> will note, however, that this is a work item AI which has not yet been
> considered by the full ARG. (It wasn't discussed at the recent meeting).
> The write-up is based on E-Mail discussion and aan existing
> implementation survey.

Thanks for pointing this out to me.

> The e-mail in the appendix is interesting; it is awful long for such a
> simple issue!

It certainly is interesting. FWIW, this is the first time I have needed
Slice, and I assumed the same bounds as To_String (U) (Low .. High). I
was using GNAT, so I got bit. Since the ARM has nothing to say on the
bounds, I tested it with another compiler and saw that its results
differed.

> Anyway, I think it wouldn't be too prudent to depend on any particular
> bounds from Slice until this issue is resolved.

I try to avoid compiler dependencies. The work around is fairly straight
forward:

declare
   S : constant String (Low .. High) := Slice (U, Low, High);
begin
   Statements where you would like to use Slice directly
end;

-- 
Jeff Carter
"Hello! Smelly English K...niggets."
Monty Python & the Holy Grail