Re: Restarting Tread: Why isn't this program working with

[anon@anon.org (anon)]

--
--  Three different versions.  All version use 8-bits instead of 7-bits 
--  because integer version of 200.0 may not fit in a 7-bit code.
--  use declare blocks to separate versions.
--
with Ada.Integer_Text_IO ;
with Ada.Float_Text_IO ;

with Ada.Text_IO ;
use  Ada.Text_IO ;

with Ada.Unchecked_Conversion;

with Interfaces ;
use  Interfaces ;

procedure test2 is
  subtype Short_integer1 is INTEGER range -(2 ** 7)..((2 ** 7) - 1);
  subtype A_Float is Float;

  subtype Short_integer2 is Integer range 0.. ((2 ** 8) - 1);
  subtype A_Natural is Natural range 0..((2 ** 8) - 1);

  --FYI1
  Size_Of_Float : integer := Float'Size;                  -- 32
  Size_Of_short_int: integer := Short_integer1'Size;      -- 10 !!!!!!! Size is 10

  --FYI2
  Size_Of_short_integer: integer := Short_integer2'Size;  -- 8
  Size_Of_Natural: integer := A_Natural'Size;             -- 8

  Arg    : A_Float;
  Result : Short_integer1;


Begin

   -- will cause error due to integer version of 200 is 
   -- greater than 2**7

  begin
    Arg := 200.0;
    Result := Short_integer1(Arg);
  exception
    when Constraint_Error =>
      Put_Line ( "Constraint_Error using Short_integer1" ) ;
  end ;

  -- using files 

  declare
   Temp_String : String ( 1..10 ) ; 
   Temp : Integer ; 
   Last : Positive ;
   Result2 : Short_integer2;
 
  begin
    Arg := 200.0;
    Ada.Float_Text_IO.Put ( Temp_String, Arg, Aft => 0, Exp => 0 ) ;
    Ada.Integer_Text_IO.Get ( Temp_String, Temp, Last ) ;
    Result2 := Short_integer2(Temp);
    Put_Line ( "Temp :=> " & Temp_String ) ;
    Put ( "Result from file :=> " ) ;
    Ada.Integer_Text_IO.Put ( Result2 ) ;
    New_Line ;
  exception
    when Constraint_Error =>
      Put_Line ( "Constraint_Error using Files" ) ;
      Put_Line ( "Temp :=> " & Temp_String ) ;
  end ;



  -- Works but the number may be greater than 7 bits code.

  declare 
    function To_Integer is new Ada.Unchecked_Conversion 
                          ( Float, Integer ) ;
    Temp : Integer ; 
  begin
    Arg := 200.0;
    Temp := To_Integer ( Arg ) ;
    Put ( "Result :=> " ) ;
    Ada.Integer_Text_IO.Put ( Temp ) ;
    new_line ;
  exception
    when Constraint_Error =>
      Put_Line ( "Constraint_Error using Unchecked_Conversion" ) ;
  end ;


  -- Works but the number may be greater than 7 bits code, so using 8

  declare 
    type Irec is array ( 0..3 ) of Unsigned_8 ;
                       
    function To_Integer is new Ada.Unchecked_Conversion 
                          ( Float, Irec ) ;
    Temp : Irec ; 
  begin
    Arg := 200.0;
    Temp := To_Integer ( Arg ) ;
    Put ( "Result :=> " ) ;
      for index in IRec'range loop
        Ada.Integer_Text_IO.Put ( Integer ( Temp ( index ) ), 8, 16 );
      end loop ;
    new_line ;
  exception
    when Constraint_Error =>
      Put_Line ( "Constraint_Error using Unchecked_Conversion" ) ;
  end ;
End test2;



In <83d19cd8-71ca-43c1-a3eb-05832290e565@r36g2000prf.googlegroups.com>, ChristopherL <clusardi2k@aol.com> writes:
>I'm restarting the tread [How to put 200 into an integer sub-type of
>16 bits (code included)] with a new subject because the last was too
>long!
>
>How can I be getting the below error message with
>"Unchecked_Conversion".
>
>Isn't Unchecked_conversion just suppose to copy bits?
>
>I want to copy bits from an Ada float to a user defined short integer
>maintaining the same bit representation.
>
>Arg:Float;  -- From this with a value of 200
>subtype Short_integer is Integer range -(2 ** 7) .. ((2 ** 7) - 1 );
>Result: Short_integer; --to this, and I want to round Arg
>
>The definitions of Arg and Result2 can not chanage.
>
>Chris L.
>
>with Unchecked_Conversion;
>
>procedure test is
>  subtype Short_integer1 is Natural range 0.. ((2 ** 10) - 1);
>  subtype Short_integer2 is Integer range -(2 ** 7)..((2 ** 7) - 1);
>
>  subtype A_Float is Float;
>
>  subtype A_Natural is Natural range 0..((2 ** 8) - 1);
>  -- The next line of code (if used) gives compilation error message:
>  -- A_NATURAL does not denote a first subtype
>  -- for A_Natural'Size use Short_integer1'Size;
>
>  Size_Of_Float : integer :=3D Float'Size;      --32 bits long
>
>  Size_Of_short_integer: integer :=3D Short_integer1'Size;--10 bits
>long
>  Size_Of_short_int: integer :=3D Short_integer2'Size;--10 bits long
>
>  Size_Of_Natural: integer :=3D A_Natural'Size;       --8 bits long
>
>  Arg     : A_Float;
>  Result2 : Short_integer2;
>  Result1 : Short_integer1;
>
>  function Get_Bits is new Unchecked_Conversion (Source =3D>
>    Short_integer1, Target =3D> Short_integer2);
>
>Begin
>
>Arg :=3D 200.0;
>
>Result1 :=3D Short_integer1(Arg + 0.5);  -- Result1 becomes 201
>Result2 :=3D Get_Bits (Result1);
>
>End test;
>
>-- Error Message
>+++ Program  started at 01/15/09 12:14:02
>
>Unhandled exception:
>
>CONSTRAINT_ERROR raised in MAIN
>
>Range_Check_Failed
>
>Exception raised at code address: 0x413516
>+++ Program completed with exit code 1 at 01/15/09 12:14:02
>+++
>---------------------------------------------------------------------------=
>=AD-----------------------------------