CODEWITHSUNDEEP
compiler-errorsada
thmasker
thmasker

Reputation: 638

Error using packages

I have the following program:

with Ada.Text_IO;
with pkg_task;
with pkg_procedure;

procedure exercise2 is
    my_task : task_t;
begin
    loop
        my_task.ConsultsState;
    end loop;
end;

which uses the following package pkg_task:

with Text_IO;

package body pkg_task is
    task body task_t is
        entry IsEven(N: Integer) is
            EvenConsult : Integer := 0;
            OddConsult : Integer := 0;
        begin
            if N rem 2 = 0 then
                Put_Line("Number " & N & " is even");
                EvenConsult := EvenConsult + 1;
            else
                Put_Line("Number " & N & " is odd");
                OddConsult := OddConsult + 1;
            end if;
        end IsEven;

        entry ConsultsState is
        begin
            Put_Line("Total even numbers consulted: " & EvenConsult);
            Put_Line("Total odd numbers consulted: " & OddConsult);
        end ConsultsState;
    end task_t;
end pkg_task;

when I compile, I get this error: 

gcc-4.9 -c exercise2.adb
exercise2.adb:6:19: "task_t" is not visible
exercise2.adb:6:19: non-visible declaration at pkg_task.ads:2
exercise2.adb:9:17: invalid prefix in selected component "my_task"
gnatmake: "exercise2.adb" compilation error

I don't know how to fix it.

Upvotes: 0

Views: 244

Answers (1)

Faibbus
Faibbus

Reputation: 1133

This is the difference between scope and visibility.

with pkg_task; means that this pkg_task is now in your scope, but its elements are not directly visible.

Therefore, in order to use task_t you can either prefix it with the package name : pkg_task.task_t, or make the type visible with a use clause (use pkg_task;).

For more information on this topic, you can check Ada Distilled.

Upvotes: 4

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