loop on character

[Bernd.Specht@gmx.com (Bernd Specht)]

Although I've worked with Ada for a few years, I've got a problem now that 
looks a bit like a beginners problem to me. Can someone help me?

I wrote a statement like this:

for c in '0'..'9'
loop
...
end loop;

and the compiler says "ambigous character literals (could be 
Wide_Character)"

what would be the correct way to write this?

Ok, I can declare some variables first, but I think there must be a better 
way.

low : Character := '0';
high : Character  := '9';

for c in low .. high
loop
...
end loop;