c460011.a

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-- C460011.A
--
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--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
--     PARTICULAR PURPOSE OF SAID MATERIAL.
--*
--
-- OBJECTIVE:
--     Check that conversion of a decimal type to a modular type raises
--     Constraint_Error when the operand value is outside the base range
--     of the modular type.
--     Check that a conversion of a decimal type to an integer type
--     rounds correctly.
--
-- TEST DESCRIPTION:
--      Test conversion from decimal types to modular types.  Test
--      conversion to mod 255, mod 256 and mod 258 to test the boundaries
--      of 8 bit (+/-) unsigned numbers.
--      Test operand values that are negative, the value of the mod,
--      and greater than the value of the mod.
--      Declare a generic test procedure and instantiate it for each of the
--      unsigned types for each operand type.
--      Check that the the operand is properly rounded during the conversion.
--
-- APPLICABILITY CRITERIA:
--      This test is applicable to all implementations which support
--      decimal types.
--
-- CHANGE HISTORY:
--      24 NOV 98   RLB  Split decimal cases from C460008 into this
--                       test, added conversions to integer types.
--      18 JAN 99   RLB  Repaired errors in test.
--
--!

------------------------------------------------------------------- C460011

with Report;

procedure C460011 is

  Shy_By_One   : constant := 2**8-1;
  Heavy_By_Two : constant := 2**8+2;

  type Unsigned_Edge_8 is mod Shy_By_One;
  type Unsigned_8_Bit  is mod 2**8;
  type Unsigned_Over_8 is mod Heavy_By_Two;

  type Signed_8_Bit is range -128 .. 127;
  type Signed_Over_8 is range -200 .. 200;

  NPC : constant String := " not properly converted";

  procedure Assert( Truth: Boolean; Message: String ) is
  begin
    if not Truth then
      Report.Failed(Message);
    end if;
  end Assert;

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

  type Decim is delta 0.1 digits 5;    -- N/A => ERROR.

  generic
    type Source is delta <> digits <>;
    type Target is mod <>;
  procedure Decimal_Conversion_Check( For_The_Value : Source;
                                      Message       : String );

  procedure Decimal_Conversion_Check( For_The_Value : Source;
                                      Message       : String ) is

    Item : Target;

  begin  
    Item := Target( For_The_Value );
    Report.Failed("Deci expected Constraint_Error " & Message);
    Report.Comment("Value of" & Target'Image(Item) & NPC);
  exception
    when Constraint_Error => null; -- expected case
    when others => Report.Failed("Deci raised wrong exception " & Message);
  end Decimal_Conversion_Check;

  procedure Decim_To_Short is
    new Decimal_Conversion_Check( Decim, Unsigned_Edge_8 );

  procedure Decim_To_Eight is
    new Decimal_Conversion_Check( Decim, Unsigned_8_Bit );

  procedure Decim_To_Wide is
    new Decimal_Conversion_Check( Decim, Unsigned_Over_8 );

  function Identity( Launder: Decim ) return Decim is
    Flat_Broke : constant Decim := 0.0;
  begin
    if Report.Ident_Bool( Launder = Flat_Broke ) then
      return Flat_Broke;
    else
      return Launder;
    end if;
  end Identity;

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

begin  -- Main test procedure.

  Report.Test ("C460011", "Check that conversion to " &
                          "a modular type raises Constraint_Error when " &
                          "the operand value is outside the base range " &
                          "of the modular type" );
   
  -- Decimal Error cases

  Decim_To_Short( Identity( -5.00 ), "M2S Dynamic, Negative" );
  Decim_To_Short( Shy_By_One * 1.0, "M2S Static,  At_Mod" );
  Decim_To_Short( 1995.9, "M2S Static,  Over_Mod" );

  Decim_To_Eight( -0.5, "M28 Static, Negative" );
  Decim_To_Eight( 2.0*128, "M28 Static,  At_Mod" );
  Decim_To_Eight( Identity( 2001.2 ), "M28 Dynamic, Over_Mod" );

  Decim_To_Wide ( Decim'First, "M2W Static,  Negative" );
  Decim_To_Wide ( Identity( 2*128.0 +2.0 ), "M2W Dynamic, At_Mod" );
  Decim_To_Wide ( Decim'Last, "M2W Static,  Over_Mod" );

  -- Check a few, correct, edge cases, for modular types.

  Eye_Dew: declare
    Sense     : Decim    := 0.00;

    Little   : Unsigned_Edge_8;
    Moderate : Unsigned_8_Bit;
    Big      : Unsigned_Over_8;

  begin
    Moderate := Unsigned_8_Bit (Sense);
    Assert( Moderate = 0, "Sense => Moderate, 0");

    Sense     := 2*128.0;

    Big := Unsigned_Over_8 (Sense);
    Assert( Big = 256, "Sense => Big, 256");

  end Eye_Dew;

  Rounding: declare
    Easy     : Decim  := Identity ( 2.0);
    Simple   : Decim  := Identity ( 2.1);
    Halfway  : Decim  := Identity ( 2.5);
    Upward   : Decim  := Identity ( 2.8);
    Chop     : Decim  := Identity (-2.2);
    Neg_Half : Decim  := Identity (-2.5);
    Downward : Decim  := Identity (-2.7);

    Little   : Unsigned_Edge_8;
    Moderate : Unsigned_8_Bit;
    Big      : Unsigned_Over_8;

    Also_Little:Signed_8_Bit;
    Also_Big : Signed_Over_8;
    
  begin
    Little := Unsigned_Edge_8 (Easy);
    Assert( Little = 2, "Easy => Little, 2");

    Moderate := Unsigned_8_Bit (Simple);
    Assert( Moderate = 2, "Simple => Moderate, 2");

    Big := Unsigned_Over_8 (Halfway); -- Rounds up by 4.6(33).
    Assert( Big = 3, "Halfway => Big, 3");

    Little := Unsigned_Edge_8 (Upward);
    Assert( Little = 3, "Upward => Little, 3");

    Also_Big := Signed_Over_8 (Halfway); -- Rounds up by 4.6(33).
    Assert( Also_Big = 3, "Halfway => Also_Big, 3");

    Also_Little := Signed_8_Bit (Chop);
    Assert( Also_Little = -2, "Chop => Also_Little, -2");

    Also_Big := Signed_Over_8 (Neg_Half); -- Rounds down by 4.6(33).
    Assert( Also_Big = -3, "Halfway => Also_Big, -3");

    Also_Little := Signed_8_Bit (Downward);
    Assert( Also_Little = -3, "Downward => Also_Little, -3");

  end Rounding;


  Report.Result;

end C460011;