Re: old problem

[Anh Vo <anhvofrcaus@gmail.com>]

On Thursday, May 30, 2019 at 3:26:17 AM UTC-7, Gilbert Gosseyn wrote:
> with Ada.Numerics; use Ada.Numerics;
> with Ada.Numerics.Generic_Real_Arrays;
> package allx is
>    type Real is digits 18;
>    package RA is new Ada.Numerics.Generic_Real_Arrays(Real);
>    use RA;
>    Dx,Dy,gK : Positive;
>    subtype RM is Real_Matrix(1..Dy,1..Dx);
>    type weight_array is array(1..gK) of RM;
> end allx;
> 
> with allx; use allx;
> with Ada.Text_IO;use Ada.Text_IO;
> procedure testall is
>    package RIO is new Float_IO(Real);
>    use RIO;
>    use allx.RA;
>    W : weight_array;
>    D : RM := (others => (others => 1.0));
>    procedure testallx(D1 : RM;
>                       W1 : in out weight_array) is
>    begin
>       for i in 1..gK loop
>          W1(i) := Real(i)*D1;
>       end loop;
>    end testallx;
> 
> begin
>    Dx := 3;
>    Dy := 5;
>    gK := 3;
>    testallx(D,W);
>    for k in 1..Dx loop
>       new_line(2);
>       for i in 1..Dy loop
>          new_line;
>          for j in 1..gK loop
>             RIO.put(W(k)(i,j));
>          end loop;
>       end loop;
>    end loop;
> end testall;
> 
> raised CONSTRAINT_ERROR : testall.adb:13  (W1(i) := ...)  index check failed, and of course if I use numbers in package allx, then W1(i) is known.
> How to keep the dimensions Dx,Dy,gK open until execution?

Lines 7 and 8 will trigger a CONSTRAINT_ERROR warning when this problem is compiled under GNAT. 

Replace 

   subtype RM is Real_Matrix(1..Dy,1..Dx); 
   type weight_array is array(1..gK) of RM; 

with 
   
   Max : constant := 100;  -- can be adjusted
   subtype Index_Range is Positive range 1 .. Max;
   subtype RM is Real_Matrix(Index_Range, Index_Range); 
   type weight_array is array(Index_Range) of RM; 

Anh Vo