separate (Compilation_Unit.Produce_Metrics)
procedure Generic_Type_Definition
             (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

    --=======================================================
    -- Generic_Type_Definition ::=
    --     "(" "<> ")"
    --   | ( [ "RANGE" | "DIGITS" | "DELTA" ] ) "<>"
    --   | Array_Type_Definition
    --   | Access_Type_Definition
    --   | Private_Type_Definition
    --=======================================================

    Current_Token : Token_Package.Token;

begin
    -- Generic_Type_Definition

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

        when Token_Package.Left_Parenthesis_Token =>
            Get_Next_Token (Out_Token => Current_Token,
                            From => Current_Compilation_Unit,
                            Current_Loc => Loc);

            Get_Next_Token (Out_Token => Current_Token,
                            From => Current_Compilation_Unit,
                            Current_Loc => Loc);

            if "/=" (Token_Package.Value_Of (Current_Token),
                     Token_Package.Box_Token) then
                raise Syntax_Error;
            end if;

            -- increment Halstead BOX operator count
            Halstead.Store_Operator ((Kind => Halstead_Operator.Box_Halstead));

            Get_Next_Token (Out_Token => Current_Token,
                            From => Current_Compilation_Unit,
                            Current_Loc => Loc);

            if "/=" (Token_Package.Value_Of (Current_Token),
                     Token_Package.Right_Parenthesis_Token) then
                raise Syntax_Error;
            end if;

            -- increment Halstead PARENTHESES operator count
            Halstead.Store_Operator
               ((Kind => Halstead_Operator.Parentheses_Halstead));

        when Token_Package.Range_Token | Token_Package.Digits_Token |
             Token_Package.Delta_Token =>

            Get_Next_Token (Out_Token => Current_Token,
                            From => Current_Compilation_Unit,
                            Current_Loc => Loc);
            case Token_Package.Value_Of (Current_Token) is

                when Token_Package.Range_Token =>
                    -- increment Halstead RANGE operator count
                    Halstead.Store_Operator
                       ((Kind => Halstead_Operator.Range_Halstead));

                when Token_Package.Digits_Token =>
                    -- increment Halstead DIGITS operator count
                    Halstead.Store_Operator
                       ((Kind => Halstead_Operator.Digits_Halstead));

                when Token_Package.Delta_Token =>
                    -- increment Halstead DELTA operator count
                    Halstead.Store_Operator
                       ((Kind => Halstead_Operator.Delta_Halstead));

                when others =>
                    null;

            end case;

            Get_Next_Token (Out_Token => Current_Token,
                            From => Current_Compilation_Unit,
                            Current_Loc => Loc);

            if "/=" (Token_Package.Value_Of (Current_Token),
                     Token_Package.Box_Token) then
                raise Syntax_Error;
            end if;

            -- increment Halstead BOX operator count
            Halstead.Store_Operator ((Kind => Halstead_Operator.Box_Halstead));

        when Token_Package.Array_Token =>

            Array_Type_Definition
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when Token_Package.Access_Token =>

            Access_Type_Definition
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when Token_Package.Limited_Token | Token_Package.Private_Token =>

            Private_Type_Definition
               (Current_Compilation_Unit => Current_Compilation_Unit,
                Program_Unit => Program_Unit,
                Halstead => Halstead,
                Loc => Loc,
                Mccabe => Mccabe);

        when others =>
            raise Syntax_Error;

    end case;

end Generic_Type_Definition;