Jump to content

pyscripter

Members
 View Profile  See their activity

  • Content Count

    1019

  • Joined

  • Last visited

  • Days Won

    66

Posts posted by pyscripter

  1. Posted 

    np_array.SetItem(0) 

     

    should work.

     

    From VarPyth source code:

      

              // here we handle a special case: COM (or Delphi?) doesn't allow you to have index properties
          // on a variant except from a true array variant! So if myVar is a Python variant that holds
          // a Python list, I can't write something like: myVar[0]! But if the list is a member of a
          // Python instance, it will work fine! Like: myInst.myList[0]
          // So, to handle this problem we detect some special names: GetItem, SetItem and Length
          // that will do the same as:
          // myList[0] <-> myList.GetItem(0)
          // myDict['Hello'] := 1 <-> myDict.SetItem('Hello', 1)
          // len(myList) <-> myList.Length()
          // we get some bonus with the slices and in operators also:
          // myList = [0, 1, 2, 3]; myList.GetSlice(1, 2) --> [1, 2]
          // myList.Contains(2) <-> 2 in myList

     

  10. Posted · Edited by pyscripter

    I always thought class vars are supposed to be initialized.  See also this Stackoverflow question.

    However in Alexandria 11.1 I got bitten by this:


      

    type
  TMyComponent = class(TComponent)
  public
    class var GlobalInstance: TMyComponent ;
    constructor Create(AOwner: TComponent); override;
  end

constructor TMyComponent .Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  if Assigned(GlobalInstance) then
    raise Exception.Create('TMyComponent is a singleton.  You can only have one!');
  GlobalInstance := Self;
end;

     

    When I added such a component to a data module in the 11.1 IDE an exception was raised.  It was working fine with 11.0.   Was I making a wrong assumption or is this an Alexandria 11.1 bug?


    Update:  My stupid fault.  Actually the error has occurred when I closed one project and opened another one with the same component. I should set the GlobalInstance to nil in the desctructor, which I did not.   Even then the above approach is problematic if for instance you have have two projects in the same project group using this component.   I think this would create a problem.

     

    Any better way of having a singleton component without causing issues in the IDE? 

  11. Posted

    The master branch of https://github.com/TurboPack/SynEdit contains the latest version of SynEdit.

     

    Apparently, the compiler directive should be 

    {$IF CompilerVersion <= 33}

    and this has now been fixed.  SynEdit strives to be compatible with Delphi Berlin and later.  If you find incompatibilities please report them to the issue tracker so that they can be fixed.

     

    There were many new properties introduced and some removed, so forms with SynEdit need to be loaded and saved again after installing the new version.   Just ignore the errors you get opening the files.

     

     

     

  14. Posted · Edited by pyscripter

    I was trying to improve the performance of SynEdit in handling files with super long lines (e.g. 50K characters).  In doing so I came across an unexpected optimization that had a spectacular impact on performance.

     

    See this innocent looking function probably written two decades ago (fCasedLine is a PChar): 

    function TSynCustomHighlighter.GetToken: string;
var
  Len: Integer;
begin
  Len := Run - fTokenPos;
  SetLength(Result, Len);
  if Len > 0 then
    StrLCopy(@Result[1], fCasedLine + fTokenPos, Len);
end;

    By measuring I found that this function (called zillions of times) was a bottleneck and replaced it with: 

    function TSynCustomHighlighter.GetToken: string;
var
  Len: Integer;
begin
  Len := Run - fTokenPos;
  SetString(Result, fCasedLine + fTokenPos, Len);
end;

    The impact was massive.

    Both SetString and  StrLCopy in x64 are implemented in pascal (not assembly) using Move.   So initially I was puzzled.

     

    However here is the reason.  Look at StrLCopy: 

    function StrLCopy(Dest: PWideChar; const Source: PWideChar; MaxLen: Cardinal): PWideChar;
var
  Len: Cardinal;
begin
  Result := Dest;
  Len := StrLen(Source);
  if Len > MaxLen then
    Len := MaxLen;
  Move(Source^, Dest^, Len * SizeOf(WideChar));
  Dest[Len] := #0;
end;

    Can you see the problem?  It is the call to StrLen(Source)!  In my case the Source was very very long strings, the length of which was unnecessarily calculated the hard way.    The lesson here is that you need to identify the bottlenecks by measuring.  You may be in for surprises, sometimes pleasant ones,
     

     

    • Like 9

  18. Posted

    28 minutes ago, Uwe Raabe said:

    They are static by design. The why I cannot answer. Unfortunately there is nothing we can do about it.

    This looks like an inconsistency in the language with regard to class methods and class properties.  And I don't think it is documented.

     

  19. Posted · Edited by pyscripter

    3 hours ago, Uwe Raabe said:

    Class properties are static

    You access class properties through a class or an instance reference.  That reference could be passed to a virtual class getter. Why do they have to be static?  This is my question.

    A related question.  How do virtual class methods work? Is there an equivalent to VMT for classes?

     

    By the way this works correctly: 

    class Test
protected
  class function GetValue: string; virtual;
public
  property Value: string read GetValue;
end;

    i.e. a normal property with a virtual class getter

  20. Posted · Edited by pyscripter

    I tried to do something like 

    class Test
protected
  class function GetValue: string; virtual;
public
  class property Value: string read GetValue;
end;

    and I got a compiler error message stating the class property read specifier has to be either a class var or a static class method.   Any idea about the reason for this restriction?

  22. Posted · Edited by pyscripter

    1 hour ago, Stefan Glienke said:

    Could be DirectWrite related if you have a rather poor onboard GPU. Check CPU and GPU usage when it's lagging.

    This is correct, but this is the reason GPU support is disabled by default:

      

          D2D1RenderTargetProperties(
        {$IFDEF GPUSupport}
        D2D1_RENDER_TARGET_TYPE_DEFAULT,
        {$ELSE}
        D2D1_RENDER_TARGET_TYPE_SOFTWARE, // much faster in my desktop with a slow GPU
        {$ENDIF}


    As far as CPU utilization goes, I have tried with a 10K lines pascal file with highlighting, code folding and indentation lines.   Scrolling by pressing continuously the Page Down key results in CPU utiliization around 5% (I7 12700).

    With GPUSupport enabled (currently incompatible with Gutter.ShowLineNumbers - will be fixed), CPU utilization remains close to 0% but GPU utilization rises to 5% (Intel UHD 770).

  23. Posted

    I will ask Embarcadero to update the Getit packages once the current versions is thoroughly tested and optimized, probably in a few weeks time. 

    But the latency you mentioned is always going to be there, since the development is currently very active.  So if you want the latest fixes and improvements do use the Github version.

  24. Posted

    17 hours ago, dados said:

    nd the first thing I do is scroll up and down (page up/down and with mouse dragging vertical scrollbar) ......and the scrolling is lagging/studdering

    This is not the experience here and in the other testers.  Performance with highlighted 10000s of lines is very good.   Could you please submit an issue at the Issue Tracker with sample project and text file?

  25. Posted · Edited by pyscripter

    There were many options mentioned in this thread, but there was no mention of the most obvious one at least on Windows: the built-in Windows spellchecker available since Windows 8.  There many advantages compared to the options discussed here.

    • It is free.
    • Very easy to use.
    • Minimal code to add to your project.
    • No need to distribute dictionaries.  If the user wants a given language dictionary they can get it through Windows language settings.
    • It persists words added, ignored and autocorrected.
    • It detects duplicate words.

    I got the idea from Ian Boyed's answer in this Stackoverflow question, but I could not find a Delphi translation of the Windows Spellcheck API.  So I created my own.   It is included in the attached zip file, along with a demo program.

     

    image.thumb.png.71b6adb9e8eed0d12460dcad8ea8fdb4.png

    SpellCheck.zip

    • Like 1
    • Thanks 5
×