separate (Compilation_Unit.Produce_Metrics)
procedure Constraint (Current_Compilation_Unit : in out Ada_Compilation_Unit;
                      Program_Unit : in Program_Unit_State_Machine;
                      Halstead : in Halstead_State_Machine;
                      Loc : in Loc_State_Machine;
                      Mccabe : in Mccabe_State_Machine) is

    --=======================================================
    -- Constraint ::=
    --     Range_Constraint          -> "RANGE"
    --   | Floating_Point_Constraint -> "DIGITS"
    --   | Fixed_Point_Constraint    -> "DELTA"
    --   | Aggregate                 -> "("
    --=======================================================

    Dummy_Count : Natural;

begin
    -- Constraint

    case Token_Package.Value_Of (Peek (From => Current_Compilation_Unit)) is

        when Token_Package.Range_Token =>
            Range_Constraint
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when Token_Package.Digits_Token =>
            Floating_Point_Constraint
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when Token_Package.Delta_Token =>
            Fixed_Point_Constraint
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when Token_Package.Left_Parenthesis_Token =>
            Aggregate (Current_Compilation_Unit => Current_Compilation_Unit,
                       Program_Unit => Program_Unit,
                       Halstead => Halstead,
                       Loc => Loc,
                       Mccabe => Mccabe,
                       Number_Of_Components => Dummy_Count);

        when others =>
            raise Syntax_Error;

    end case;

end Constraint;