Natools

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with Ada.Containers.Indefinite_Doubly_Linked_Lists;
with Natools.S_Expressions;

private with Ada.Containers.Indefinite_Ordered_Maps;
private with Ada.Containers.Indefinite_Ordered_Sets;
private with Ada.Finalization;

package Natools.Smaz_Tools is
   pragma Preelaborate;

   package String_Lists is new Ada.Containers.Indefinite_Doubly_Linked_Lists
     (String);

   procedure Read_List
     (List : out String_Lists.List;
      Descriptor : in out S_Expressions.Descriptor'Class);
      --  Read atoms from Descriptor to fill List


   List_For_Linear_Search : String_Lists.List;
   function Linear_Search (Value : String) return Natural;
      --  Function and data source for inefficient but dynamic function
      --  that can be used with Dictionary.Hash.

   procedure Set_Dictionary_For_Map_Search (List : in String_Lists.List);
   function Map_Search (Value : String) return Natural;
      --  Function and data source for logarithmic search using standard
      --  ordered map, that can be used with Dictionary.Hash.

   type Search_Trie is private;
   procedure Initialize (Trie : out Search_Trie; List : in String_Lists.List);
   function Search (Trie : in Search_Trie; Value : in String) return Natural;
      --  Trie-based search in a dynamic dictionary, for lookup whose
      --  speed-vs-memory is even more skewed towards speed.

   procedure Set_Dictionary_For_Trie_Search (List : in String_Lists.List);
   function Trie_Search (Value : String) return Natural;
      --  Function and data source for trie-based search that can be
      --  used with Dictionary.Hash.


   type String_Count is range 0 .. 2 ** 31 - 1;
      --  Type for a number of substring occurrences

   package Methods is
      type Enum is (Encoded, Frequency, Gain);
   end Methods;

   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, Natural);

   Search_Map : Dictionary_Maps.Map;

   type Trie_Node;
   type Trie_Node_Access is access Trie_Node;
   type Trie_Node_Array is array (Character) of Trie_Node_Access;

   type Trie_Node (Is_Leaf : Boolean) is new Ada.Finalization.Controlled
     with record
      Index : Natural;

      case Is_Leaf is
         when True  => null;
         when False => Children : Trie_Node_Array;
      end case;
   end record;

   overriding procedure Adjust (Node : in out Trie_Node);
   overriding procedure Finalize (Node : in out Trie_Node);

   type Search_Trie is record
      Not_Found : Natural;
      Root : Trie_Node (False);
   end record;

   Trie_For_Search : Search_Trie;

end Natools.Smaz_Tools;