I'm using a library in ada which contains many types :

type Int8 is range -8 ** 7 .. 2 ** 7 - 1;
subtype T_Name_String is Int8;
type T_Name_String_Fixed20 is array (range 1..20) of T_Name_String ;

And there is a record with :

type The_Record is record
   name : T_Name_String_Fixed20;
   -- and others
end record;

I can't change that, I don't know why there are using Int8 for ada strings but I'm not able to initiate the field name. I've try :

-- First try:
MyRecord.name = "hello               ";
-- Error : expected type T_Name_String_Fixed20 found a string type

-- Second try
Ada.Strings.Fixed.Move(Target => MyRecord.name;
                       Source => "hello               "

Please solve this in ADA:

        --initialize first array (My_Array) with random binary values
    procedure Init_Array (Arr : BINARY_ARRAY) is
        package Random_Bit is new Ada.Numerics.Discrete_Random (BINARY_NUMBER);
        use Random_Bit;
        G : Generator;
    begin
        Reset (G);
        for Index in 1..16 loop
            Arr(Index) := Random(G); 
        end loop;
    end Init_Array;

        --reverse binary array
    procedure Reverse_Bin_Arr (Arr : BINARY_ARRAY) is
        hold : BINARY_ARRAY := Arr;
    begin
        for Index in 1..16 loop
            Arr(15 - Index) := hold(Index);
        end loop;
    end Reverse_Bin_Arr;

   --initialize first array (My_Array) with random binary values
   procedure Init_Array (Arr: in out BINARY_ARRAY);

   --reverse binary array
   procedure Reverse_Bin_Arr (Arr : in out BINARY_ARRAY);
   

I believe my above procedures are correct. I just keep getting the following error: assgn.adb:7:15: not fully conformant with declaration at assgn.ads:7
assgn.adb:7:15: mode of "Arr" does not match
assgn.adb:19:15: not fully conformant with declaration at assgn.ads:10
assgn.adb:19:15: mode of "Arr" does not match
gnatmake: "assgn.adb" compilation error

The first procedure should initialize a random array that houses each bit of a binary number. Example: [1,0,1,0,1,1,1,1,0,0,0,1,1,0,1,0]

The second procedure should reverse the bits in the binary array.

I would like to create an array and access it in the following way for read and write slice operations (i.e. more than one element at once):

• If the indices are within range access them as usual
• If the second index is smaller than the first index, access the data as follows: First .. A'Last & A'First .. (First + 5) (turns out this doesn't work as-is due to concatenation result upper bound out of range)

I have come up with the following example to demonstrate the issue:

with Ada.Text_IO;
use  Ada.Text_IO;

procedure Test_Modular is
    type Idx is mod 10;
    type My_Array is array (Idx range <>) of Integer;

    A: My_Array(Idx) := (
        0 => 0, 1 => 1, 2 => 2, 3 => 3, 4 => 4, 5 => 5,
        6 => 6, 7 => 7, 8 => 8, 9 => 9
    );

    First: constant Idx := 7;

    S: constant My_Array := A(First .. First + 5);
begin

    for I in S'range loop
        Put_Line(Idx'Image(I) & " --> " & Integer'Image(S(I)));
    end loop;

end Test_Modular;

As in the example, the 5 is static, the compiler warns me as follows:

$ gnatmake -o test_modular test_modular.adb
x86_64-linux-gnu-gcc-10 -c test_modular.adb
test_modular.adb:18:19: warning: loop range is null, loop will not execute
x86_64-linux-gnu-gnatbind-10 -x test_modular.ali
x86_64-linux-gnu-gnatlink-10 test_modular.ali -o test_modular

When running the program, I observe the following:

$ ./test_modular

i.e. no output as predicted by the compiler warning.

Now I wonder: Is there a way to write the slice like A(First .. First + 5) and make it “wrap around” such that the data accessed will be the same as in this modified example program except without having to distinguish the two cases in the code explicitly?

with Ada.Text_IO;
use  Ada.Text_IO;

procedure Test_Modular_2 is
    type Idx is mod 10;
    type My_Array is array (Idx range <>) of Integer;

    A: My_Array(Idx) := (
        0 => 0, 1 => 1, 2 => 2, 3 => 3, 4 => 4, 5 => 5,
        6 => 6, 7 => 7, 8 => 8, 9 => 9
    );

    First: constant Idx := 7;

    S1: constant My_Array := A(First .. A'Last);
    S2: constant My_Array := A(A'First .. (First + 5));
begin

    for I in S1'range loop
        Put_Line(Idx'Image(I) & " --> " & Integer'Image(S1(I)));
    end loop;
    for I in S2'range loop
        Put_Line(Idx'Image(I) & " --> " & Integer'Image(S2(I)));
    end loop;

end Test_Modular_2;