------------------------------------------------------------------------------
-- Copyright (c) 2016, Natacha Porté --
-- --
-- Permission to use, copy, modify, and distribute this software for any --
-- purpose with or without fee is hereby granted, provided that the above --
-- copyright notice and this permission notice appear in all copies. --
-- --
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES --
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF --
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR --
-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES --
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN --
-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF --
-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. --
------------------------------------------------------------------------------
with Ada.Unchecked_Deallocation;
package body Natools.Smaz_Tools is
package Sx renames Natools.S_Expressions;
function Build_Node
(Map : Dictionary_Maps.Map;
Empty_Value : Natural)
return Trie_Node;
procedure Set_Map
(Map : in out Dictionary_Maps.Map;
List : in String_Lists.List);
-- Set Map contents to match List by index number
procedure Free is new Ada.Unchecked_Deallocation
(Trie_Node, Trie_Node_Access);
------------------------------
-- Local Helper Subprograms --
------------------------------
function Build_Node
(Map : Dictionary_Maps.Map;
Empty_Value : Natural)
return Trie_Node
is
function First_Character (S : String) return Character
is (S (S'First));
function Is_Current (Cursor : Dictionary_Maps.Cursor; C : Character)
return Boolean
is (Dictionary_Maps.Has_Element (Cursor)
and then First_Character (Dictionary_Maps.Key (Cursor)) = C);
function Suffix (S : String) return String;
function Suffix (S : String) return String is
begin
return S (S'First + 1 .. S'Last);
end Suffix;
use type Ada.Containers.Count_Type;
Cursor : Dictionary_Maps.Cursor;
Result : Trie_Node
:= (Ada.Finalization.Controlled with
Is_Leaf => False,
Index => Empty_Value,
Children => (others => null));
begin
pragma Assert (Dictionary_Maps.Length (Map) >= 1);
Cursor := Dictionary_Maps.Find (Map, "");
if Dictionary_Maps.Has_Element (Cursor) then
Result.Index := Dictionary_Maps.Element (Cursor);
end if;
for C in Character'Range loop
Cursor := Dictionary_Maps.Ceiling (Map, (1 => C));
if Is_Current (Cursor, C) then
if not Is_Current (Dictionary_Maps.Next (Cursor), C)
and then Dictionary_Maps.Key (Cursor) = (1 => C)
then
Result.Children (C)
:= new Trie_Node'(Ada.Finalization.Controlled with
Is_Leaf => True,
Index => Dictionary_Maps.Element (Cursor));
else
declare
New_Map : Dictionary_Maps.Map;
begin
loop
Dictionary_Maps.Insert
(New_Map,
Suffix (Dictionary_Maps.Key (Cursor)),
Dictionary_Maps.Element (Cursor));
Dictionary_Maps.Next (Cursor);
exit when not Is_Current (Cursor, C);
end loop;
Result.Children (C)
:= new Trie_Node'(Build_Node (New_Map, Empty_Value));
end;
end if;
end if;
end loop;
return Result;
end Build_Node;
function Dummy_Hash (Value : String) return Natural is
pragma Unreferenced (Value);
begin
raise Program_Error with "Dummy_Hash called";
return 0;
end Dummy_Hash;
procedure Set_Map
(Map : in out Dictionary_Maps.Map;
List : in String_Lists.List)
is
I : Natural := 0;
begin
Dictionary_Maps.Clear (Map);
for S of List loop
Dictionary_Maps.Insert (Map, S, I);
I := I + 1;
end loop;
end Set_Map;
----------------------
-- Public Interface --
----------------------
procedure Read_List
(List : out String_Lists.List;
Descriptor : in out S_Expressions.Descriptor'Class)
is
use type Sx.Events.Event;
Event : Sx.Events.Event := Descriptor.Current_Event;
begin
String_Lists.Clear (List);
if Event = Sx.Events.Open_List then
Descriptor.Next (Event);
end if;
Read_Loop :
loop
case Event is
when Sx.Events.Add_Atom =>
String_Lists.Append
(List, Sx.To_String (Descriptor.Current_Atom));
when Sx.Events.Open_List =>
Descriptor.Close_Current_List;
when Sx.Events.End_Of_Input | Sx.Events.Error
| Sx.Events.Close_List =>
exit Read_Loop;
end case;
Descriptor.Next (Event);
end loop Read_Loop;
end Read_List;
---------------------------------
-- Dynamic Dictionary Searches --
---------------------------------
overriding procedure Adjust (Node : in out Trie_Node) is
begin
if not Node.Is_Leaf then
for C in Node.Children'Range loop
if Node.Children (C) /= null then
Node.Children (C) := new Trie_Node'(Node.Children (C).all);
end if;
end loop;
end if;
end Adjust;
overriding procedure Finalize (Node : in out Trie_Node) is
begin
if not Node.Is_Leaf then
for C in Node.Children'Range loop
Free (Node.Children (C));
end loop;
end if;
end Finalize;
procedure Initialize
(Trie : out Search_Trie;
List : in String_Lists.List)
is
Map : Dictionary_Maps.Map;
Not_Found : constant Natural := Natural (String_Lists.Length (List));
begin
Set_Map (Map, List);
Trie := (Not_Found => Not_Found,
Root => Build_Node (Map, Not_Found));
end Initialize;
function Linear_Search (Value : String) return Natural is
Result : Natural := 0;
begin
for S of List_For_Linear_Search loop
exit when S = Value;
Result := Result + 1;
end loop;
return Result;
end Linear_Search;
function Map_Search (Value : String) return Natural is
Cursor : constant Dictionary_Maps.Cursor
:= Dictionary_Maps.Find (Search_Map, Value);
begin
if Dictionary_Maps.Has_Element (Cursor) then
return Natural (Dictionary_Maps.Element (Cursor));
else
return Natural (Dictionary_Maps.Length (Search_Map));
end if;
end Map_Search;
function Search (Trie : in Search_Trie; Value : in String) return Natural is
Index : Positive := Value'First;
Position : Trie_Node_Access;
begin
if Value'Length = 0 then
return Trie.Not_Found;
end if;
Position := Trie.Root.Children (Value (Index));
loop
if Position = null then
return Trie.Not_Found;
end if;
Index := Index + 1;
if Index not in Value'Range then
return Position.Index;
elsif Position.Is_Leaf then
return Trie.Not_Found;
end if;
Position := Position.Children (Value (Index));
end loop;
end Search;
procedure Set_Dictionary_For_Map_Search (List : in String_Lists.List) is
begin
Set_Map (Search_Map, List);
end Set_Dictionary_For_Map_Search;
procedure Set_Dictionary_For_Trie_Search (List : in String_Lists.List) is
begin
Initialize (Trie_For_Search, List);
end Set_Dictionary_For_Trie_Search;
function Trie_Search (Value : String) return Natural is
begin
return Search (Trie_For_Search, Value);
end Trie_Search;
-------------------
-- Word Counting --
-------------------
procedure Add_Substrings
(Counter : in out Word_Counter;
Phrase : in String;
Min_Size : in Positive;
Max_Size : in Positive) is
begin
for First in Phrase'First .. Phrase'Last - Min_Size + 1 loop
for Last in First + Min_Size - 1
.. Natural'Min (First + Max_Size - 1, Phrase'Last)
loop
Add_Word (Counter, Phrase (First .. Last));
end loop;
end loop;
end Add_Substrings;
procedure Add_Word
(Counter : in out Word_Counter;
Word : in String;
Count : in String_Count := 1)
is
procedure Update
(Key : in String; Element : in out String_Count);
procedure Update
(Key : in String; Element : in out String_Count)
is
pragma Unreferenced (Key);
begin
Element := Element + Count;
end Update;
Cursor : constant Word_Maps.Cursor := Word_Maps.Find (Counter.Map, Word);
begin
if Word_Maps.Has_Element (Cursor) then
Word_Maps.Update_Element (Counter.Map, Cursor, Update'Access);
else
Word_Maps.Insert (Counter.Map, Word, Count);
end if;
end Add_Word;
procedure Add_Words
(Counter : in out Word_Counter;
Phrase : in String;
Min_Size : in Positive;
Max_Size : in Positive)
is
subtype Word_Part is Character with Static_Predicate
=> Word_Part in '0' .. '9' | 'A' .. 'Z' | 'a' .. 'z'
| Character'Val (128) .. Character'Val (255);
I, First, Next : Positive;
begin
if Max_Size < Min_Size then
return;
end if;
I := Phrase'First;
Main_Loop :
while I in Phrase'Range loop
Skip_Non_Word :
while I in Phrase'Range and then Phrase (I) not in Word_Part loop
I := I + 1;
end loop Skip_Non_Word;
exit Main_Loop when I not in Phrase'Range;
First := I;
Skip_Word :
while I in Phrase'Range and then Phrase (I) in Word_Part loop
I := I + 1;
end loop Skip_Word;
Next := I;
if Next - First in Min_Size .. Max_Size then
Add_Word (Counter, Phrase (First .. Next - 1));
end if;
end loop Main_Loop;
end Add_Words;
procedure Filter_By_Count
(Counter : in out Word_Counter;
Threshold_Count : in String_Count)
is
Position, Next : Word_Maps.Cursor;
begin
Position := Word_Maps.First (Counter.Map);
while Word_Maps.Has_Element (Position) loop
Next := Word_Maps.Next (Position);
if Word_Maps.Element (Position) < Threshold_Count then
Word_Maps.Delete (Counter.Map, Position);
end if;
Position := Next;
end loop;
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);
begin
return Scored_Word'
(Size => Word'Length,
Word => Word,
Score => Score (Word_Maps.Element (Cursor), Word'Length, Method));
end To_Scored_Word;
end Natools.Smaz_Tools;