PiedSoftware

In Delphi in System.Class we have this declaration: TShiftState = set of (ssShift, ssAlt, ssCtrl, ssLeft, ssRight, ssMiddle, ssDouble, ssTouch, ssPen, ssCommand, ssHorizontal); Given that declaration, how can I declare a variable that will be just one of those values?

Thanks for thinking about it Dave. But ... It already knows the type of a to be an array, so a set interpretation is ruled out. And for arrays, nil and [] mean the same thing. That is why the assignment operator works. So, I think it is reasonable to expect the compile to test for equality with the same syntax.

I like the way Delphi is getting better at arrays, but there is still a gap in the compiler that let me down. I tried this code in 12.2 to highlight the issue. const nostrings: tarray<string> = []; procedure TForm1.FormShow(Sender: TObject); begin var a: tarray<string>; a := []; if a = nostrings then say('nostrings'); if a = [] then say('it''s blank'); end; procedure TForm1.say(const s: string); begin ListBox1.Items.Add(s); end; This refuses to compile at the line if a = [] then with the error "Incompatible types". But it has no problem with the assignment, so it looks like the programmers have just put this in the "do eventually" basket. Does anyone have any insights into this? --- Mark

Yes, definitely. XCode does that, and you need it.

Yes, it would be much better if sets has a different punctuation from arrays. Sets came first though, and they got [ and ] on a first come first choose basis. If Delphi could yield { and } from comments and give it to arrays or sets, life would be better.

The way Swift works is that you can declare value with either the keyword let or the keyword var. If you use let the value cannot be changed. But the expression you assign to a let value can be anything available at that point.

I guess I am a bit spoiled playing with Swift. It lets you assign any expression to a constant, compile time or run time.

Yes, David, I agree. I would like them to fill that out: everything that is logically able to be evaluated at compile time should be assignable to a constant.

type TCodeStructure = record StartTkn: string; EndTkn: string; SubTkns: array of string; end; type TIfTkns = (itElse, itElsif); const elseTkn = '#else'; elsifTkn = '#elseif'; IfTkns: array[TIfTkns] of string = (elseTkn, elsifTkn); IfStruct: TCodeStructure = (StartTkn: '#if'; EndTkn: '#endif'; SubTkns: [IfTkns[itElse], IfTkns[itElsif]]); I wrote this code and got the error "E2026 Constant expression expected" on the last line. I also tried SubTkns: IfTkns); When I changed it to SubTkns: [elseTkn, elsifTkn]); it compiled happily. and that gave me E2010 Incompatible types: 'Dynamic array' and 'Array'. To me it seems that Delphi should allow the first thing I tried - referencing a const array via constant indices to specify a constant. There is no reason to disallow that sort of thing. Ideally even the second attempt should be reasonable. I have Delphi 10.4.

I went to Component | Install Packages and unchecked "Embarcadero LiveBindings Components" and saved, but when I closed and reopened Delphi, it was back on again. D'oh! I'm concerned the maybe a library is using it. How can I work that out? Should I remove it?

Thank. What I am comparing are the 2 functions from the Delphi Run menu: Run (f9) and Run without debugging (shift-ctrl-f9)

I don't think we have that package in the app at all. We certainly haven't coded that way.

Delphi 10.4 MySQL, but I don't think that is the issue. I probably shouldn't have mentioned it. It was my first thought, I put timings in the code. The time is just the form getting created, with no database activity. It looks fine when it has loaded Yes, I know it's pretty diffuse. I haven't started pulling my hair out yet.

Hi I have been trying to work out what is going on with one of my forms. Just opening it, which has only a small amount of DB activity, was taking nearly a minute in the debugger, once it was about 35s. But when I run it without the debugger it is less than 3 seconds. There is no obvious bottlenecks in Task Manager. I have 8 GB of RAM. Does this sound familiar to anyone? Does anyone have a possible solution? Regards Mark

I think I may have solved the problem. Somehow the normal run button got replaced with the Run without debugging button. So far the best explanation is that when I had the problem was when I ran the program by hitting the Run button, and when it ran fine it was because I hit F9. I don't remember changing it, and I don't remember whether I hit F9 or the button each time I had breakpoints or not, But, now I am back in happy land.