--  Programmed by Jedidiah Barber
--  Licensed under the Sunset License v1.0

--  See license.txt for further details


with

    Ada.Text_IO,
    Kompsos.Math,
    Kompsos.Pretty_Print;


procedure Logo is

    package TIO renames Ada.Text_IO;


    package InKomp is new Kompsos (Integer);
    use InKomp;

    package Math is new InKomp.Math (0, 1);

    package Printer is new InKomp.Pretty_Print (Integer'Image);


    function B
           (Item : in Natural)
        return Term
    renames Math.Build;

    function P
           (Item : in Integer)
        return String
    renames Printer.Image;

    function PV
           (Item : in Term)
        return String is
    begin
        return P (Math.Value (Item));
    exception
    when others =>
        return Printer.Image (Item);
    end PV;


    procedure Test
           (Power, Base : in Natural)
    is
        Relation : Goal := Empty_Goal;
        Exponent  : constant Term := Relation.Fresh;
        Remainder : constant Term := Relation.Fresh;
        Result : State;
    begin
        Math.Logarithm (Relation, B (Power) & B (Base) & Exponent & Remainder);
        Result := Relation.Run;
        TIO.Put_Line ("log_" & P (Base) & " (" & P (Power) & ") = " &
            PV (Exponent.Resolve (Result)) & " r " & PV (Remainder.Resolve (Result)));
    end Test;

begin

    TIO.Put_Line ("Logarithm");
    Test (1, 1);
    Test (68, 2);
    Test (68, 3);
    Test (68, 4);
    Test (68, 5);
    Test (68, 6);
    Test (68, 7);
    Test (68, 8);

    TIO.New_Line;

    TIO.Put_Line ("Expected Failure");
    --  Here there is no reasonable way to assign a value to the exponent variable term
    Test (68, 1);  --  1^x is always 1 so will never be 68
    --  In this case the log function is undefined for x=0
    Test (68, 0);  --  0^x is always 0 or undefined so could never be 68
    Test (0, 0);

end Logo;