Re: "unconstrained subtype in component declaration" vs "discriminant in constraint must appear alone"

[AdaMagica <christ-usch.grein@t-online.de>]

0012...@gmail.com schrieb am Dienstag, 23. Februar 2021 um 23:06:19 UTC+1:
> Please help figure out this: 
> 
> type CARDS is new cards_numbers range 1..52; 
> --> 
> 41:10 missing case values: -128 .. 0 
> 41:10 missing case values: 5 .. 127 
> 41:25 subtype of expression is not static, alternatives must cover base type 
> from --> 
> [card in CARDS, of course] 
> case (card / 13) +1 is 
> when 1 => put("Spades"); 
> when 2 =>put("Hearts"); 
> when 3 =>put("Spades"); 
> when 4 =>put("Clovers"); 
> end case; 
> 
> how can the compiler not know that CARD is limited from 1 to 52, including 0 for the base type (type Cards_numbers is range 0..52) 

Because Card/13 + 1 is a value in CARDS, and there is a rule that all values of the type must be covered.
Define a subtype covering only 1..4 and subtype convert the expression, then it shoud be fine.