------------------------------------------------------------------------------
-- 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. --
------------------------------------------------------------------------------
package body Natools.Smaz.Tools is
package Sx renames Natools.S_Expressions;
function Dummy_Hash (Value : String) return Natural;
-- Placeholder for Hash member, always raises Program_Error
function Image (B : Boolean) return String;
-- Return correctly-cased image of B
------------------------------
-- Local Helper Subprograms --
------------------------------
function Dummy_Hash (Value : String) return Natural is
pragma Unreferenced (Value);
begin
raise Program_Error with "Dummy_Hash called";
return 0;
end Dummy_Hash;
function Image (B : Boolean) return String is
begin
if B then
return "True";
else
return "False";
end if;
end Image;
----------------------
-- Public Interface --
----------------------
function Linear_Search (Value : String) return Natural is
Result : Ada.Streams.Stream_Element := 0;
begin
for S of List_For_Linear_Search loop
exit when S = Value;
Result := Result + 1;
end loop;
return Natural (Result);
end Linear_Search;
procedure Print_Dictionary_In_Ada
(Dict : in Dictionary;
Hash_Image : in String := "TODO";
Max_Width : in Positive := 70;
First_Prefix : in String := " := (";
Prefix : in String := " ";
Half_Indent : in String := " ")
is
procedure Append_Entity
(Buffer : in out String;
Last : in out Natural;
Entity : in String);
function Double_Quote (S : String; Count : Natural) return String;
function Offsets_Suffix (I : Ada.Streams.Stream_Element) return String;
function Strip_Image (S : String) return String;
function Values_Separator (I : Positive) return String;
procedure Append_Entity
(Buffer : in out String;
Last : in out Natural;
Entity : in String) is
begin
if Last + 1 + Entity'Length <= Buffer'Last then
Buffer (Last + 1) := ' ';
Buffer (Last + 2 .. Last + 1 + Entity'Length) := Entity;
Last := Last + 1 + Entity'Length;
else
Put_Line (Buffer (Buffer'First .. Last));
Last := Buffer'First + Prefix'Length - 1;
Buffer (Last + 1 .. Last + Half_Indent'Length) := Half_Indent;
Last := Last + Half_Indent'Length;
Buffer (Last + 1 .. Last + Entity'Length) := Entity;
Last := Last + Entity'Length;
end if;
end Append_Entity;
function Double_Quote (S : String; Count : Natural) return String is
begin
if Count = 0 then
return S;
else
return Quoted : String (1 .. S'Length + Count) do
declare
O : Positive := Quoted'First;
begin
for I in S'Range loop
Quoted (O) := S (I);
O := O + 1;
if S (I) = '"' then
Quoted (O) := S (I);
O := O + 1;
end if;
end loop;
end;
end return;
end if;
end Double_Quote;
function Offsets_Suffix (I : Ada.Streams.Stream_Element) return String is
begin
if I < Dict.Offsets'Last then
return ",";
else
return "),";
end if;
end Offsets_Suffix;
function Strip_Image (S : String) return String is
begin
if S'Length > 0 and then S (S'First) = ' ' then
return S (S'First + 1 .. S'Last);
else
return S;
end if;
end Strip_Image;
function Values_Separator (I : Positive) return String is
begin
if I > Dict.Values'First then
return "& ";
else
return "";
end if;
end Values_Separator;
Line_Buffer : String (1 .. Max_Width + Prefix'Length);
Buffer_Last : Natural;
begin
Put_Line (First_Prefix & "Dict_Last =>"
& Ada.Streams.Stream_Element'Image (Dict.Dict_Last) & ',');
Put_Line (Prefix & "String_Size =>"
& Natural'Image (Dict.String_Size) & ',');
Put_Line (Prefix & "Variable_Length_Verbatim => "
& Image (Dict.Variable_Length_Verbatim) & ',');
Put_Line (Prefix & "Max_Word_Length =>"
& Natural'Image (Dict.Max_Word_Length) & ',');
Line_Buffer (1 .. Prefix'Length) := Prefix;
Line_Buffer (Prefix'Length + 1 .. Prefix'Length + 11) := "Offsets => ";
Buffer_Last := Prefix'Length + 11;
for I in Dict.Offsets'Range loop
Append_Entity (Line_Buffer, Buffer_Last, Strip_Image
(Positive'Image (Dict.Offsets (I)) & Offsets_Suffix (I)));
if I = Dict.Offsets'First then
Line_Buffer (Prefix'Length + 12) := '(';
end if;
end loop;
Put_Line (Line_Buffer (Line_Buffer'First .. Buffer_Last));
Line_Buffer (Prefix'Length + 1 .. Prefix'Length + 9) := "Values =>";
Buffer_Last := Prefix'Length + 9;
declare
I : Positive := Dict.Values'First;
First, Last : Positive;
Quote_Count : Natural;
begin
Values_Loop :
while I <= Dict.Values'Last loop
Add_Unprintable :
while Dict.Values (I) not in ' ' .. '~' loop
Append_Entity
(Line_Buffer, Buffer_Last,
Values_Separator (I) & Character'Image (Dict.Values (I)));
I := I + 1;
exit Values_Loop when I > Dict.Values'Last;
end loop Add_Unprintable;
First := I;
Quote_Count := 0;
Find_Printable_Substring :
loop
if Dict.Values (I) = '"' then
Quote_Count := Quote_Count + 1;
end if;
I := I + 1;
exit Find_Printable_Substring when I > Dict.Values'Last
or else Dict.Values (I) not in ' ' .. '~';
end loop Find_Printable_Substring;
Last := I - 1;
Split_Lines :
loop
declare
Partial_Quote_Count : Natural := 0;
Partial_Width : Natural := 0;
Partial_Last : Natural := First - 1;
Sep : constant String := Values_Separator (First);
Available_Length : constant Natural
:= (if Line_Buffer'Last > Buffer_Last + Sep'Length + 4
then Line_Buffer'Last - Buffer_Last - Sep'Length - 4
else Line_Buffer'Length - Prefix'Length
- Half_Indent'Length - Sep'Length - 3);
begin
if 1 + Last - First + Quote_Count < Available_Length then
Append_Entity
(Line_Buffer, Buffer_Last,
Sep & '"' & Double_Quote
(Dict.Values (First .. Last), Quote_Count) & '"');
exit Split_Lines;
else
Count_Quotes :
loop
if Dict.Values (Partial_Last + 1) = '"' then
exit Count_Quotes
when Partial_Width + 2 > Available_Length;
Partial_Width := Partial_Width + 1;
Partial_Quote_Count := Partial_Quote_Count + 1;
else
exit Count_Quotes
when Partial_Width + 1 > Available_Length;
end if;
Partial_Width := Partial_Width + 1;
Partial_Last := Partial_Last + 1;
end loop Count_Quotes;
Append_Entity
(Line_Buffer, Buffer_Last, Sep & '"'
& Double_Quote
(Dict.Values (First .. Partial_Last),
Partial_Quote_Count)
& '"');
First := Partial_Last + 1;
Quote_Count := Quote_Count - Partial_Quote_Count;
end if;
end;
end loop Split_Lines;
end loop Values_Loop;
Put_Line (Line_Buffer (Line_Buffer'First .. Buffer_Last) & ',');
end;
Line_Buffer (Prefix'Length + 1 .. Prefix'Length + 7) := "Hash =>";
Buffer_Last := Prefix'Length + 7;
Append_Entity (Line_Buffer, Buffer_Last, Hash_Image & ");");
Put_Line (Line_Buffer (Line_Buffer'First .. Buffer_Last));
end Print_Dictionary_In_Ada;
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;
function To_Dictionary
(List : in String_Lists.List;
Variable_Length_Verbatim : in Boolean)
return Dictionary
is
Dict_Last : constant Ada.Streams.Stream_Element
:= Ada.Streams.Stream_Element (String_Lists.Length (List)) - 1;
String_Size : Natural := 0;
Max_Word_Length : Positive := 1;
begin
for S of List loop
String_Size := String_Size + S'Length;
if S'Length > Max_Word_Length then
Max_Word_Length := S'Length;
end if;
end loop;
declare
Offsets : Offset_Array (0 .. Dict_Last);
Values : String (1 .. String_Size);
Current_Offset : Positive := 1;
Current_Index : Ada.Streams.Stream_Element := 0;
Next_Offset : Positive;
begin
for S of List loop
Offsets (Current_Index) := Current_Offset;
Next_Offset := Current_Offset + S'Length;
Values (Current_Offset .. Next_Offset - 1) := S;
Current_Offset := Next_Offset;
Current_Index := Current_Index + 1;
end loop;
pragma Assert (Current_Index = Dict_Last + 1);
pragma Assert (Current_Offset = String_Size + 1);
return
(Dict_Last => Dict_Last,
String_Size => String_Size,
Variable_Length_Verbatim => Variable_Length_Verbatim,
Max_Word_Length => Max_Word_Length,
Offsets => Offsets,
Values => Values,
Hash => Dummy_Hash'Access);
end;
end To_Dictionary;
-------------------
-- 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 Evaluate_Dictionary
(Dict : in Dictionary;
Corpus : in String_Lists.List;
Compressed_Size : out Ada.Streams.Stream_Element_Count;
Counts : out Dictionary_Counts)
is
Verbatim_Code_Count : constant Ada.Streams.Stream_Element_Offset
:= Ada.Streams.Stream_Element_Offset
(Ada.Streams.Stream_Element'Last - Dict.Dict_Last);
Verbatim_Length : Ada.Streams.Stream_Element_Offset;
Input_Byte : Ada.Streams.Stream_Element;
begin
Compressed_Size := 0;
for I in Counts'Range loop
Counts (I) := 0;
end loop;
for S of Corpus loop
declare
use type Ada.Streams.Stream_Element_Offset;
Compressed : constant Ada.Streams.Stream_Element_Array
:= Compress (Dict, S);
Index : Ada.Streams.Stream_Element_Offset := Compressed'First;
begin
Compressed_Size := Compressed_Size + Compressed'Length;
while Index in Compressed'Range loop
Input_Byte := Compressed (Index);
if Input_Byte in Dict.Offsets'Range then
Counts (Input_Byte) := Counts (Input_Byte) + 1;
Index := Index + 1;
else
if not Dict.Variable_Length_Verbatim then
Verbatim_Length := Ada.Streams.Stream_Element_Offset
(Ada.Streams.Stream_Element'Last - Input_Byte) + 1;
elsif Input_Byte < Ada.Streams.Stream_Element'Last then
Verbatim_Length := Ada.Streams.Stream_Element_Offset
(Ada.Streams.Stream_Element'Last - Input_Byte);
else
Index := Index + 1;
Verbatim_Length := Ada.Streams.Stream_Element_Offset
(Compressed (Index)) + Verbatim_Code_Count - 1;
end if;
Index := Index + Verbatim_Length + 1;
end if;
end loop;
end;
end loop;
end Evaluate_Dictionary;
function Simple_Dictionary
(Counter : in Word_Counter;
Word_Count : in Natural)
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));
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;
function To_Scored_Word (Cursor : in Word_Maps.Cursor)
return Scored_Word
is
Word : constant String := Word_Maps.Key (Cursor);
begin
return Scored_Word'
(Size => Word'Length,
Word => Word,
Score => Score_Value (Word_Maps.Element (Cursor)) * Word'Length);
end To_Scored_Word;
end Natools.Smaz.Tools;