Eliminating empty strings in TStringList when reading from text file.

[Bart]

If I understand the test code correclty, then each test loads the file from disk.
Since disk-reads are cached by the OS, this isn't really fair, at least not for the first testmethod that is called.

Bart

[Bart]

You obviously are using something that looks like a blank line but isn't...

The part of the code that checks for failure uses a simple check for a string being completely empty.

Bart

[avk]

Please provide a file!!!!!!!!!!!!!!!!!!!!

Save the result of the CreateStringList function to a file and you will get the required one.

@Bart, please note that the first file load is only for counting non-empty lines.

[jamie]

I completely remove the line Endings so when the chunk of memory is complete its gone!

This can be verified by the fact that I have both a Write and Read pointers, at the write pointer is far behind the read pointer and thus a NUL is placed at the end of the stream.

 Using the debugger will verify this by stepping through it via the ST pointer I put there only for debugging usage.
   
  Over here it works fine but I use  MEMO to view the results and it's all working fine..

 I need the same file he is using for the test, I suspect there could be control or other chars in there that are not normally visible

[avk]

@jamie, did you read my post #62?

[BrunoK]

My entry (as long as it complies with the benchmark conditions ...)

Code: Pascal  [Select][+][-]

1.   procedure RemovEmptyLinesBruno(aList: TStringList);
2.   var
3.     lList : TStringList;
4.     lString : string;
5.     i : integer;
6.   begin
7.     lList := TStringList.Create;
8.     lList.Assign(aList);
9.     aList.Clear;
10.     for i := 0 to lList.Count - 1 do begin
11.       lString := lList.Strings[i];
12.       if lString<>'' then
13.         aList.Add(lString);
14.     end;
15.     lList.Free;
16.   end;
17.  

[avk]

Done:

Code: Text  [Select][+][-]

1. DelEmptyLinesMax        elapsed time(ms): 3385
2. DelEmptyLinesBart       elapsed time(ms): 2521
3. DelEmptyLinesThaddy     elapsed time(ms): 75 (failure)
4. DelEmptyLinesWinny      elapsed time(ms): 3147
5. DelEmptyLinesAvk        elapsed time(ms): 67
6. DelEmptyLinesJamie      elapsed time(ms): 23 (failure)
7. DelEmptyLinesEgsuh      elapsed time(ms): 78
8. DelEmptyLinesBruno      elapsed time(ms): 48
9.  

[jamie]

This conversion is done on my end.

You refuse to supply the same material you are using and what I use is working perfectly...

You guys carry on, its nothing but a MOOT subject to me now.

Nothing but noise!

[avk]

@jamie, the maximum permissible size of a file uploaded to the forum is 250KB. The test file is much larger.

[Bart]

Thaddy's code misses the last empty line.
Jamie: the file contains @194635:
e_D 6IJglfY1F6xs


82Q0H0hkEJvt9OT_

Your code misses that somehow.

The file can be build by adding this code at the beginning of the program:

Code: Pascal  [Select][+][-]

1.   TestList := CreateStringList;
2.   TestList.SaveToFile(TestFile);
3.   TestList.Free;

Since RandSeed is set, it should give the same file on each run.
(I actually created it only once)

Bart

[Bart]

I've modified the code somewhat so HasEmptyLines gives a reference to what is finds:
It will return the (zero based) index of the empty line it finds in the result and will display the preceding, offending and next line.
<EOList>  means that the found empty line is the last line in the list.

Code: [Select]

DelEmptyLinesMax        elapsed time(ms): 5618
DelEmptyLinesBart       elapsed time(ms): 4439
DelEmptyLinesThaddy     elapsed time(ms): 85 (failure "") @160252, ["xunlT3c7O9DYwtfl", "", "<EOList>"]
DelEmptyLinesWinny      elapsed time(ms): 10714
DelEmptyLinesJamie      elapsed time(ms): 53 (failure "") @160254, ["e_D 6IJglfY1F6xs", "", ""]
DelEmptyLinesEgsuh      elapsed time(ms): 229

I could not test Avk's method because of missing units.

I also write the resulting stringlist to a file and I can indeed see empty lines in the result of Jamies method.

Bart

[Thaddy]

Thaddy's code misses the last empty line.

There is an option for that. SkipLastEmpty.

[avk]

@Bart, just curious on which machine you tested?

[Bart]

@Bart, just curious on which machine you tested?

Win10, 32-bit fpc.

Bart

[avk]

Thank you, now I also want to try the 32-bit version.