Pure Pascal LZ4, LZ5 and LIZ

[LemonParty]

I applied your changes and tested compression with this program:

Code: Pascal  [Select][+][-]

1.  
2. {$Mode ObjFPC}{$H+}
3. {$R *.res}
4.  
5. uses
6.   LizSimple;
7.  
8. var
9.   S: String = 'Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word ';
10.   Compressed: String;
11. begin
12.   Compressed:= LIZ(S);
13.   Writeln(Length(S), ' ', Length(Compressed));
14.   Readln;
15. end.
16.  

The output is

170 190

Isn't the algorithm should find a pattern and make the resulting string to be smaller than input?

[Tomxe]

Isn't the algorithm should find a pattern and make the resulting string to be smaller than input?

This is a very short string and Lizard's goal is no to compress efficiently but quickly. Try with something over 1 kB.

[LemonParty]

I tried with this input data:

Code: Pascal  [Select][+][-]

1. {$Mode ObjFPC}{$H+}
2. {$R *.res}
3.  
4. uses
5.   LizSimple;
6.  
7. var
8.   S: String = 'Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word Word ';
9.   Compressed: String;
10. begin
11.   S:= S + S + S + S + S + S + S + S + S + S + S + S + S + S + S + S;
12.   Compressed:= LIZ(S);
13.   Writeln(Length(S), ' ', Length(Compressed));
14.   Readln;
15. end.
16.  

The output is:

2720 64

Nice. It works. Good job.

There is possible improvement to your library. Since FPC by default support overloading of functions (and Delphi too by adding "overload" to your function) you may short names of your functions this way:

Code: Pascal  [Select][+][-]

1. LIZCompressStreams -> LIZCompress
2. LIZDecompressStreams -> LIZDecompress
3. LIZCompressFile -> LIZCompress
4. LIZDecompressFile -> LIZDecompress

According function will be selected depend on argument you pass into it.

[Tomxe]

A candidate for future work may be UPX/UCL

UPX started