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      Template : in String;
      Index : out Ada.Streams.Stream_Element;
      Length : out Natural);

   function To_String (Data : in Ada.Streams.Stream_Element_Array)
     return String;

   function Verbatim_Size (Dict : Dictionary; Original_Size : Natural)
     return Ada.Streams.Stream_Element_Count;


   ------------------------------
   -- Local Helper Subprograms --
   ------------------------------

   function Dict_Entry
     (Dict : in Dictionary;
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            Result (I) := Character'Val (Data
              (Data'First + Ada.Streams.Stream_Element_Offset (I - 1)));
         end loop;
      end return;
   end To_String;


   function Verbatim_Size (Dict : Dictionary; Original_Size : Natural)
     return Ada.Streams.Stream_Element_Count
   is
      Verbatim1_Max_Size : constant Ada.Streams.Stream_Element_Count
        := Ada.Streams.Stream_Element_Count
            (Ada.Streams.Stream_Element'Last - Dict.Dict_Last)
         - Boolean'Pos (Dict.Variable_Length_Verbatim);
      Verbatim2_Max_Size : constant Ada.Streams.Stream_Element_Count
        := Ada.Streams.Stream_Element_Count (Ada.Streams.Stream_Element'Last)
         + Verbatim1_Max_Size;

      Remaining : Ada.Streams.Stream_Element_Count
        := Ada.Streams.Stream_Element_Count (Original_Size);
      Overhead : Ada.Streams.Stream_Element_Count := 0;
   begin
      if Dict.Variable_Length_Verbatim then
         if Remaining >= Verbatim2_Max_Size then
            declare
               Full_Blocks : constant Ada.Streams.Stream_Element_Count
                 := Remaining / Verbatim2_Max_Size;
            begin
               Overhead := Overhead + 2 * Full_Blocks;
               Remaining := Remaining - Verbatim2_Max_Size * Full_Blocks;
            end;
         end if;

         if Remaining > Verbatim1_Max_Size then
            Overhead := Overhead + 2;
            Remaining := 0;
         end if;
      end if;

      declare
         Full_Blocks : constant Ada.Streams.Stream_Element_Count
           := Remaining / Verbatim1_Max_Size;
      begin
         Overhead := Overhead + Full_Blocks;
      end;

      return Overhead + Ada.Streams.Stream_Element_Count (Original_Size);
   end Verbatim_Size;



   ----------------------
   -- Public Interface --
   ----------------------

   function Compressed_Upper_Bound
     (Dict : in Dictionary;
      Input : in String)
     return Ada.Streams.Stream_Element_Count
     return Ada.Streams.Stream_Element_Count is
   is
      Verbatim1_Max_Size : constant Natural
        := Natural (Ada.Streams.Stream_Element'Last - Dict.Dict_Last)
         - Boolean'Pos (Dict.Variable_Length_Verbatim);
      Verbatim2_Max_Size : constant Natural
        := Natural (Ada.Streams.Stream_Element'Last)
         + Verbatim1_Max_Size;
   begin
      if Dict.Variable_Length_Verbatim then
         return Ada.Streams.Stream_Element_Count (Input'Length
      return Verbatim_Size (Dict, Input'Length);
           + 2 * (Input'Length + Verbatim2_Max_Size - 1) / Verbatim2_Max_Size);
      else
         return Ada.Streams.Stream_Element_Count (Input'Length
           + (Input'Length + Verbatim1_Max_Size - 1) / Verbatim1_Max_Size);
      end if;
   end Compressed_Upper_Bound;


   procedure Compress
     (Dict : in Dictionary;
      Input : in String;
      Output_Buffer : out Ada.Streams.Stream_Element_Array;
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           (Dict,
            Input (Input_Index
                   .. Natural'Min (Input_Index + Dict.Max_Word_Length - 1,
                                   Input'Last)),
            Word,
            Length);
      end Find_Entry;

      Previous_Verbatim_Beginning : Natural := 0;
      Previous_Verbatim_Last : Ada.Streams.Stream_Element_Offset := 0;
   begin
      Output_Last := Output_Buffer'First - 1;
      Find_Entry;

      Main_Loop :
      while Input_Index in Input'Range loop
         Data_In_Dict :
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            Verbatim_Scan :
            while Length = 0 and Input_Index in Input'Range loop
               Input_Index := Input_Index + 1;
               Find_Entry;
            end loop Verbatim_Scan;

            Verbatim_Length := Input_Index - Beginning;

            if Previous_Verbatim_Beginning > 0
              and then Output_Last + Verbatim_Size (Dict, Verbatim_Length)
                 > Previous_Verbatim_Last + Verbatim_Size
                    (Dict, Input_Index - Previous_Verbatim_Beginning)
            then
               Beginning := Previous_Verbatim_Beginning;
               Output_Last := Previous_Verbatim_Last;
               Verbatim_Length := Input_Index - Beginning;
            else
               Previous_Verbatim_Beginning := Beginning;
               Previous_Verbatim_Last := Output_Last;
            end if;

            Verbatim_Encode :
            while Verbatim_Length > 0 loop
               if Dict.Variable_Length_Verbatim
                 and then Verbatim_Length > Verbatim1_Max_Size
               then
                  Block_Length := Natural'Min