Re: How to access an array using two different indexing schemes

[Jerry <list_email@icloud.com>]

On Thursday, November 30, 2017 at 2:50:31 PM UTC-7, Randy Brukardt wrote:
> 
> The only thing that does work is the type conversion in parameter passing 
> (as I originally illustrated). So something like the following should work 
> (should because I didn't try it):
> 
The type conversion at the subroutine level also works for an open array in the formal argument. The following uses an array which is accessed by an access variable--the "usual" declaration method also works, i.e,. if x is declared as 

x : Real_Vector(-4 .. 3);


with Ada.Text_IO; use Ada.Text_IO;
with Ada.Numerics.Long_Real_Arrays; use Ada.Numerics.Long_Real_Arrays;

procedure Randy_V3 is
    type Real_Vector_Access is access Real_Vector;
    x_Ptr : Real_Vector_Access := new Real_Vector(-4 .. 3);
        x : Real_Vector renames x_Ptr.all;
    subtype RV0_7 is Real_Vector(0..7);

    procedure Do_X(x : in out Real_Vector) is
    begin
        for i in x'range loop
            x(i) := x(i) + 0.1;
            Put_Line(i'img & "  " & x(i)'img);
        end loop;
    end Do_X;

    procedure Do_Y(y : in out RV0_7) is
    begin
        for i in y'range loop
            y(i) := y(i) + 0.2;
            Put_Line(i'img & "  " & y(i)'img);
        end loop;
    end Do_Y;

    procedure Do_Y_Open(y : in out Real_Vector) is
    begin
        for i in y'range loop
            y(i) := y(i) + 0.3;
            Put_Line(i'img & "  " & y(i)'img);
        end loop;
    end Do_Y_Open;

begin
    x := (-4.0, -3.0, -2.0, -1.0, 0.0, 1.0, 2.0, 3.0);
    Do_X(x);
    New_Line;
    Do_Y(RV0_7(x));
    New_Line;
    Do_Y_Open(RV0_7(x));
end Randy_V3;


-4  -3.90000000000000E+00
-3  -2.90000000000000E+00
-2  -1.90000000000000E+00
-1  -9.00000000000000E-01
 0   1.00000000000000E-01
 1   1.10000000000000E+00
 2   2.10000000000000E+00
 3   3.10000000000000E+00

 0  -3.70000000000000E+00
 1  -2.70000000000000E+00
 2  -1.70000000000000E+00
 3  -7.00000000000000E-01
 4   3.00000000000000E-01
 5   1.30000000000000E+00
 6   2.30000000000000E+00
 7   3.30000000000000E+00

 0  -3.40000000000000E+00
 1  -2.40000000000000E+00
 2  -1.40000000000000E+00
 3  -4.00000000000000E-01
 4   6.00000000000000E-01
 5   1.60000000000000E+00
 6   2.60000000000000E+00
 7   3.60000000000000E+00

Jerry