Re: Supporting full Unicode

[Ludovic Brenta <ludovic.brenta@insalien.org>]

Brian Catlin asked:
> The complete definition of Unicode allows for 2-,3-, and 4-byte
> characters. How is this supported in Ada95 and Ada0y?

I am not aware of any differences between Ada 95 and Ada 2005 in that
respect.  Ada 95 has a type Wide_Character, "whose values correspond
to the 65536 code positions of the ISO 10646 Basic Multilingual Plane
(BMP)." (RM 3.5.2(3)).  So, Ada 95 supports the UCS-2 encoding
natively.  The other standard type, Character, is defined as Latin-1.

As you can see, there is no standard support for 3- and 4-byte
characters; you would have to support them in a nonstandard way, e.g.

type Wide_Wide_Character is mod 2**32; -- UCS-4
type Wide_Wide_String is array (Natural range <>) of Wide_Wide_Character;

But I would favour using UTF-8 as the internal encoding anyway.  It is
easy to define a UTF8_String type similar to the above.  GtkAda has
such a type, as GTK+ uses UTF-8 as both internal and external
encoding.

-- 
Ludovic Brenta.


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