Re: The extension of Is_Basic to unicode (about AI12-0260-1)

["J-P. Rosen" <rosen@adalog.fr>]

Le 12/04/2018 à 01:57, ytomino a écrit :
> If Character.Handling.Is_Basic can not be changed because
> compatibility, still more, this *overloading* will create new problem
> for the future.
> 
> For example, on rewriting some applications from Character to
> Wide_Character, it may be imagined that two meanings of Is_Basic will
> confuse.
> Or, they makes hard to use "use clause", or use as a generic formal
> subprogram.
If you are adapting a program to use the full BMP instead of Latin1,
expect many more difficult issues and/or incompatibilities than this one...

> Excuse me for repeating, should new function name be used for new
> definition?
> 
>   function Is_Base (Item : Wide_Character) return Boolean; -- according with Unicode
>   function Is_Basic (Item : Wide_Character) return Boolean is (Is_Base (Item) and Is_Letter (Item)); -- for compatibility

This is technically doable, but not obviously desirable. This
incompatibility seems to me to be a candidate to the following comment,
already used for some other incompatibilities:

"This incompatibility is likely to fix more bugs than it will create"

-- 
J-P. Rosen
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