Natools

      pragma Assert (for all Count of Counter.Map => Count >= Threshold_Count);
   end Filter_By_Count;


   function Simple_Dictionary
     (Counter : in Word_Counter;
      Word_Count : in Natural;
      Method : in Methods.Enum := Methods.Encoded)
     return String_Lists.List
   is
      use type Ada.Containers.Count_Type;
      Target_Count : constant Ada.Containers.Count_Type
        := Ada.Containers.Count_Type (Word_Count);
      Set : Scored_Word_Sets.Set;
      Result : String_Lists.List;
   begin
      for Cursor in Word_Maps.Iterate (Counter.Map) loop
         Scored_Word_Sets.Include (Set, To_Scored_Word (Cursor, Method));

         if Scored_Word_Sets.Length (Set) > Target_Count then
            Scored_Word_Sets.Delete_Last (Set);
         end if;
      end loop;

      for Cursor in Scored_Word_Sets.Iterate (Set) loop
         Result.Append (Scored_Word_Sets.Element (Cursor).Word);
      end loop;

      return Result;
   end Simple_Dictionary;


   procedure Simple_Dictionary_And_Pending
     (Counter : in Word_Counter;
      Word_Count : in Natural;
      Selected : out String_Lists.List;
      Pending : out String_Lists.List;
      Method : in Methods.Enum := Methods.Encoded;
      Max_Pending_Count : in Ada.Containers.Count_Type
        := Ada.Containers.Count_Type'Last)
   is
      use type Ada.Containers.Count_Type;
      Target_Count : constant Ada.Containers.Count_Type
        := Ada.Containers.Count_Type (Word_Count);
      Set : Scored_Word_Sets.Set;
   begin
      for Cursor in Word_Maps.Iterate (Counter.Map) loop
         Scored_Word_Sets.Insert (Set, To_Scored_Word (Cursor, Method));
      end loop;

      Selected := String_Lists.Empty_List;
      Pending := String_Lists.Empty_List;

      for Cursor in Scored_Word_Sets.Iterate (Set) loop
         if String_Lists.Length (Selected) < Target_Count then
            Selected.Append (Scored_Word_Sets.Element (Cursor).Word);
         else
            Pending.Append (Scored_Word_Sets.Element (Cursor).Word);
            exit when String_Lists.Length (Selected) >= Max_Pending_Count;
         end if;
      end loop;
   end Simple_Dictionary_And_Pending;


   function To_Scored_Word
     (Cursor : in Word_Maps.Cursor;
      Method : in Methods.Enum)
     return Scored_Word
   is
      Word : constant String := Word_Maps.Key (Cursor);
      Factor : Score_Value;
   begin
      case Method is
         when Methods.Encoded => Factor := Word'Length;
         when Methods.Frequency => Factor := 1;
         when Methods.Gain => Factor := Word'Length - 1;
      end case;

      return Scored_Word'
        (Size => Word'Length,
         Word => Word,
         Score => Score_Value (Word_Maps.Element (Cursor)) * Factor);
   end To_Scored_Word;


   function Worst_Index
     (Dict : in Dictionary;
      Counts : in Dictionary_Counts;
      Method : in Methods.Enum)

   procedure Filter_By_Count
     (Counter : in out Word_Counter;
      Threshold_Count : in String_Count);
      --  Remove from Counter all entries whose count is below the threshold

   function Simple_Dictionary
     (Counter : in Word_Counter;
      Word_Count : in Natural;
      Method : in Methods.Enum := Methods.Encoded)
     return String_Lists.List;
      --  Return the Word_Count words in Counter that have the highest score,
      --  the score being count * length.

   procedure Simple_Dictionary_And_Pending
     (Counter : in Word_Counter;
      Word_Count : in Natural;
      Selected : out String_Lists.List;
      Pending : out String_Lists.List;
      Method : in Methods.Enum := Methods.Encoded;
      Max_Pending_Count : in Ada.Containers.Count_Type
        := Ada.Containers.Count_Type'Last);
      --  Return in Selected the Word_Count words in Counter that have the
      --  highest score, and in Pending the remaining words,
      --  the score being count * length.

   type Dictionary_Counts is

      Score : Score_Value;
   end record;

   function "<" (Left, Right : Scored_Word) return Boolean
     is (Left.Score > Right.Score
         or else (Left.Score = Right.Score and then Left.Word < Right.Word));

   function To_Scored_Word
     (Cursor : in Word_Maps.Cursor;
      Method : in Methods.Enum)
     return Scored_Word;

   package Scored_Word_Sets is new Ada.Containers.Indefinite_Ordered_Sets
     (Scored_Word);

   package Dictionary_Maps is new Ada.Containers.Indefinite_Ordered_Maps
     (String, Ada.Streams.Stream_Element);