Re: Ada case-statement

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

Le 15/03/2018 à 16:37, Stephen Davies a écrit :
> On Wednesday, 14 March 2018 23:16:29 UTC, Randy Brukardt  wrote:
> 
>> declare
>>   Selector : Day_Type renames Calculate_Day;
>>   subtype Weekend_Subtype is Day_Type range Sat .. Sun;
>>      -- Or use a static predicate if the range is discontiguous.
>> begin
>>   case Selector is
>>       when Mon .. Fri =>
>>          ...
>>       when  Sat | Sun =>
>>          ...
>>          case Weekend_Subtype'(Selector) is -- A type conversion works, too.
>>             when Sat =>
>>                ...
>>             when Sun =>
>>                ...
>>          end case;
>>    end case;
>> end;
> 
> Unless this has changed in more recent compilers, the static predicate
> when Sat & Sun are not contiguous does not work. Gnatpro 7.0.2 complains
> about missing values. Also, attempting to use "when Weekend_Subtype" in
> the outer case-statement results in complaints about duplicate values.
> 
It IS contiguous in countries where the week starts on Monday...

BTW, for you who start the week on Sunday, isn't Sunday part of the
week-END? ;-)

-- 
J-P. Rosen
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