Re: Range types

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

Christos Chryssochoidis <C.Chryssochoidis@gmail.com> writes:

> I would like to define a subtype of Wide_Character for a program that
> processes (unicode) text. This type would represent the Greek
> letters. Greek letters in Unicode, with all their diacritics, are
> located in two separate ranges: 0370 - 03D7 and 1F00 - 1FFF.

That's a reasonable thing to want, but Ada doesn't support that directly
-- you have to program it yourself.

>... That's 360
> characters to write in an enumeration... Since gaps are not allowed in
> ranges, I 'm thinking instead of defining such a type, to define a
> function that would accept a Wide_Character as argument and return a
> boolean value indicating whether the given Wide_Character falls in the
> ranges of the Greek characters.

Right.  And perhaps a conversion function that converts from
[Wide_?]Wide_Character to Greek_Letter, and raises an exception if it's
not a greek letter.

- Bob