qualified expressions acting as names - not accepted?

qualified expressions acting as names - not accepted?

[G.B.]

The compiler accepts line (1) below, but neither (2) or (3).
It says it is expecting Standard.Integer, not Standard.Boolean.
Is this a bug in the program or bug in the compiler?
(String'("AZ")(1) in a similar program is accepted.)

procedure Qualified is
    type S is array (Boolean) of Character;
    
    X: Character;
    Z: constant S := "AZ";
begin
    X := Z       (False);	-- (1)
    X := S'(Z)   (False);	-- (2)
    X := S'("AZ")(False);	-- (3)
end;


-- 
"HOTDOGS ARE NOT BOOKMARKS"
Springfield Elementary teaching staff

Re: qualified expressions acting as names - not accepted?

[Shark8]

>     X := S'("AZ")(False);	-- (3)

This should be X := S'('A','Z')(False);

>     X := S'(Z)   (False);	-- (2)

This should be compilable, as you're essentially asserting that Z is type-S, and accessing False should result in a character.

Re: qualified expressions acting as names - not accepted?

[AdaMagica]

indexed_component ::= prefix(expression {, expression})
prefix ::= name | implicit_dereference
name ::= 
     direct_name | explicit_dereference
   | indexed_component | slice
   | selected_component | attribute_reference
   | type_conversion | function_call
   | character_literal | qualified_expression
   | generalized_reference | generalized_indexing
qualified_expression ::= 
   subtype_mark'(expression) | subtype_mark'aggregate

With this excerpt from the syntax, it looks like your compiler has a problem.

Re: qualified expressions acting as names - not accepted?

[G.B.]

On 22.08.16 12:00, AdaMagica wrote:
> With this excerpt from the syntax, it looks like your compiler has a problem.

So it seems. I have dropped a note.

Apparently, the compiler treats arrays of components of
type Character specially (also those of type Wide_Character,
or of type Wide_Wide_Character). Substituting a user defined
character type for the component type restores the expected
behavior.


-- 
"HOTDOGS ARE NOT BOOKMARKS"
Springfield Elementary teaching staff