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Everything posted by David Heffernan
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That's been possible for years
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Favorite feature(s) of other editors that Delphi does not offer
David Heffernan replied to dummzeuch's topic in Delphi IDE and APIs
I opened Visual Studio the other day and made some edits to a C# module that implements an API interface for our software. We have interfaces in a variety of languages, C++, Python, C#, etc. I was blown away when VS offered me suggestions for the code I was writing. Clearly it's using some AI library to do this. Honestly, the quality of the suggested code blew my mind. I knew what I wanted to write, and so did VS. This is only going to get better and better, but it's already amazing. So far as I know, there's nothing remotely like this for us Delphi users. Or would we get this is we wrote our code in an editor like VS Code?? -
Your experience with custom styles - do they work well?
David Heffernan replied to Tom F's topic in VCL
I had hope based on my QC reports from XE7 days. In any case it's a huge design mistake for Emba to implement windows themed menus as custom draw. Just let the bloody system draw it and then it will always be right!! Well, MDI excluded, but menus are getting deprecated any time soon. -
Your experience with custom styles - do they work well?
David Heffernan replied to Tom F's topic in VCL
I never submitted any. -
Your experience with custom styles - do they work well?
David Heffernan replied to Tom F's topic in VCL
Ha ha ha. I think we all know the answer to this. They can't even do menus properly. Even for the standard windows theme the menus are custom drawn and the Emba code gets it wrong in various mixed dpi scenarios. When I switched to Delphi 11.3 I'd hoped to avoid having to patch the VCL to suppress its custom drawn menus. Alas that hope was doomed. -
How can I force a record to be allocated on the heap ?
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
That's fair. But it's not the subject of this discussion. -
How can I force a record to be allocated on the heap ?
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
The two versions are identical, apart from the double dereference with the class wrapper version. That's the only part that seems ugly to me. -
How can I force a record to be allocated on the heap ?
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
This is correct. Raw pointer in C++ is directly analogous to typer pointer in Delphi. However a reference to a class instance is actually no different from a raw pointer. You have to manage allocation and deallocation of both. Which is my point. -
How can I force a record to be allocated on the heap ?
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
How is this materially different? You still need to explicitly Free, and you need try/finally. The class is just extra baggage. For what gain? -
How to enable SafeSEH, CFG flags for Delphi 10.4 Dll's/Exe's?
David Heffernan replied to raj_delphi's topic in General Help
That's what I thought. What about the part that pointed out the futility of setting the flag without having the corresponding compiler support? -
You are searching with the "regular expressions" check box enabled, hence the message
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TColor breaks memory layout
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
Hmm, sucks to be you rn!! -
TColor breaks memory layout
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
This sounds like a pretty unfortunate design choice. But since your compiler knows the layout of those records you can just work with the record types and the compiler takes care of the layout. -
TColor breaks memory layout
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
It's actually very easy to predict this, once you know the rules. There is a good reason. Instead of ranting, maybe you should assume that the people that designed this knew what they were doing and that you just don't understand it. The question I have for you, is why are you so interested in size and layout of the records. What is motivating your interest. That might be helpful for us to understand. -
IntToStr algorithm (Interesting read)
David Heffernan replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
I have routines to do that. Because the Delphi code to convert between text and floats is irredeemably broken. I'm using dragon4 for float to text, but these days there are better algorithms around. I use dtoa in the other direction. My code base is spewing out a lot of floats to text files and yes it makes a significant difference to performance. Especially for files on a local drive. -
IntToStr algorithm (Interesting read)
David Heffernan replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
Kind of irrelevant whether it's heap or stack. Just that you avoid the heap allocation. -
ForEach runs only one "thread" at time
David Heffernan replied to Tommi Prami's topic in OmniThreadLibrary
The funny thing here, to my mind, is that I'd have expected that the first thing you did would have been to replace the actual function with a pointless work tasks that span in a loop for a certain period of time. If you then found that the behaviour was the same, i.e. not using all processor resources, you would know that the issue was in the library, or how you were using it. In fact had that been the case you could have come up with a very short example to capture the behaviour. You'd probably then have had an answer in an hour or two. -
IntToStr algorithm (Interesting read)
David Heffernan replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
Yes, this is it. It's a very important use case though. Imagine writing large YAML or JSON files containing a lot of data. And then imagine trying to do the same with multiple threads with extra contention on a memory manager. The point is that you build IntToStr using a function like mine above. And publish both. This allows the consumer of the library to have both options. Even if avoiding heap allocation is something that is only done in a narrow set of circumstances, that doesn't render it unnecessary. -
I guess all the software that I've released in recent times didn't happen because I was using a useless tool.
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ForEach runs only one "thread" at time
David Heffernan replied to Tommi Prami's topic in OmniThreadLibrary
Is CompressFile CPU bound? Are we supposed to know what is in there? Seems like it would be important? -
How can I force a record to be allocated on the heap ?
David Heffernan replied to dormky's topic in Algorithms, Data Structures and Class Design
This is all documented. Obviously we can tell you the answers but once you know about New, you can read the documentation to find out the rest of the details. It's really useful to know how to do that. -
If it can be done in Delphi then it can be done In Python
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value2, value3, value 4 all have an off by one error.
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IntToStr algorithm (Interesting read)
David Heffernan replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
From my codebase: // disable range checks and overflow checks so that Abs() functions in case Value = Low(Value) {$R-} {$Q-} function CopyIntegerToAnsiBuffer(const Value: Integer; var Buffer: array of AnsiChar): Integer; var i, j: Integer; val, remainder: Cardinal; negative: Boolean; tmp: array [0..15] of AnsiChar; begin negative := Value<0; val := Abs(Value); Result := 0; repeat DivMod(val, 10, val, remainder); tmp[Result] := AnsiChar(remainder + Ord('0')); Inc(Result); until val=0; if negative then begin tmp[Result] := '-'; Inc(Result); end; Assert(Result<=Length(Buffer)); i := 0; j := Result-1; while i<Result do begin Buffer[i] := tmp[j]; Inc(i); Dec(j); end; end; function CopyIntegerToWideBuffer(const Value: Integer; var Buffer: array of WideChar): Integer; var i, j: Integer; val, remainder: Cardinal; negative: Boolean; tmp: array [0..15] of WideChar; begin negative := Value<0; val := Abs(Value); Result := 0; repeat DivMod(val, 10, val, remainder); tmp[Result] := WideChar(remainder + Ord('0')); Inc(Result); until val=0; if negative then begin tmp[Result] := '-'; Inc(Result); end; Assert(Result<=Length(Buffer)); i := 0; j := Result-1; while i<Result do begin Buffer[i] := tmp[j]; Inc(i); Dec(j); end; end; function CopyInt64ToAnsiBuffer(const Value: Int64; var Buffer: array of AnsiChar): Integer; var i, j: Integer; val, remainder: UInt64; negative: Boolean; tmp: array [0..23] of AnsiChar; begin negative := Value<0; val := Abs(Value); Result := 0; repeat DivMod(val, 10, val, remainder); tmp[Result] := AnsiChar(remainder + Ord('0')); Inc(Result); until val=0; if negative then begin tmp[Result] := '-'; Inc(Result); end; Assert(Result<=Length(Buffer)); i := 0; j := Result-1; while i<Result do begin Buffer[i] := tmp[j]; Inc(i); Dec(j); end; end; function CopyInt64ToWideBuffer(const Value: Int64; var Buffer: array of WideChar): Integer; var i, j: Integer; val, remainder: UInt64; negative: Boolean; tmp: array [0..23] of WideChar; begin negative := Value<0; val := Abs(Value); Result := 0; repeat DivMod(val, 10, val, remainder); tmp[Result] := WideChar(remainder + Ord('0')); Inc(Result); until val=0; if negative then begin tmp[Result] := '-'; Inc(Result); end; Assert(Result<=Length(Buffer)); i := 0; j := Result-1; while i<Result do begin Buffer[i] := tmp[j]; Inc(i); Dec(j); end; end; {$IFDEF RANGECHECKSON}{$R+}{$ENDIF} {$IFDEF OVERFLOWCHECKSON}{$Q+}{$ENDIF} No heap allocation. I guess I could avoid that DivMod now and do something better. The main point is that a good runtime library should have building block functions like this that allow us to perform such conversions without forcing heap allocation. The RTL should have functionality like this on top of which all conversion functions can be built. Then the RTL function can be optimised and everyone benefits. -
IntToStr algorithm (Interesting read)
David Heffernan replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
The biggest issue with the Delphi code is that it forces heap allocation on you which is the real bottleneck.