generic

    type Label_Enum is (<>);
    type Element is private;
    type Element_Array is array (Positive range <>) of Element;

    with package Gen_Tokens is new Tokens (Label_Enum, Element, Element_Array);

package Packrat.Lexer is


    type Combinator_Result is new Ada.Finalization.Controlled with private;

    type Combinator is access function
           (Input : in Element_Array;
            Start : in Positive)
        return Combinator_Result;

    type Combinator_Array is array (Positive range <>) of Combinator;


    Fail_Result : constant Combinator_Result;


    function Create_Result
           (Length : in Natural;
            Status : in Result_Status;
            Value  : in Element_Array)
        return Combinator_Result;

    function Join
           (Left, Right : in Combinator_Result)
        return Combinator_Result;

    function "="
           (Left, Right : in Combinator_Result)
        return Boolean;

    function Status
           (This : in Combinator_Result)
        return Result_Status;


private


    type Element_Array_Access is access Element_Array;


    type Combinator_Result is new Ada.Finalization.Controlled with record
        Length : Natural;
        Status : Result_Status;
        Value  : Element_Array_Access;
    end record;


    overriding procedure Initialize
           (This : in out Combinator_Result);

    overriding procedure Adjust
           (This : in out Combinator_Result);

    overriding procedure Finalize
           (This : in out Combinator_Result);


    Fail_Result : constant Combinator_Result :=
       (Ada.Finalization.Controlled with
        Length => 0,
        Status => Failure,
        Value  => null);


end Packrat.Lexer;