Delphi analog to C# ?? null-coalescing operator and Light Table like debugger evaluation
Posted by jpluimers on 2017/09/05
Interesting stuff:
- https://gist.github.com/lynatan/673e574faa8343fa01d7a91e75065c54 OpOverloadWithGenerics.pas which is very similar to the C# ?? null coalescing operator [WayBack]
- DLight in-line debugger evaluation which is very similar to parts from the Light Table IDE concept [WayBack] which reminds me and others of the smalltalk days [WayBack] (https://github.com/lynatan/DLight)
- RSS feed: http://feedly.com/i/subscription/feed/http://d.hatena.ne.jp/tales/rss
- Github: https://github.com/lynatan
- Gists: https://gist.github.com/lynatan
via:
- Hatena Tales 2016-10-15 [WayBack] – DLight
- Hatena Tales 2016-09-13 [WayBack] – OpOverloadWithGenerics.pas
- Wow! Very cool! An IDE Expert that displays values of watch expressions when debugging, right inside your code editor, and it’s live! – Edwin Yip – Google+ [WayBack]
- lynatan/May-the-bevel-be-with-you: Set BevelOuter property to bvLowered in compiler progress window panels.
- Restore bevels back in compiler progress dialoghttps://github.com/lynatan/May-the-bevel-be-with-you – David Berneda – Google+ [WayBack]
In more detail:
Source: 2016-10-15 – Zenryokuwawa
And:
type
TObjectHelper = class helper for TObject
public
class function &&op_LogicalOr(A, B: T): T; static;
end;
class function TObjectHelper.&&op_LogicalOr(A, B: T): T;
begin
if A <> nil then
Result := A
else
Result := B;
end;
procedure Test;
var
sl1, sl2, sl3: TStringList;
begin
sl1 := nil;
sl2 := TStringList.Create;
sl3 := sl1 or sl2; // -> sl3 = sl2
end;
–jeroen
| type | |
| TObjectHelper = class helper for TObject | |
| public | |
| class function &&op_LogicalOr<T: class>(A, B: T): T; static; | |
| end; | |
| class function TObjectHelper.&&op_LogicalOr<T>(A, B: T): T; | |
| begin | |
| if A <> nil then | |
| Result := A | |
| else | |
| Result := B; | |
| end; | |
| procedure Test; | |
| var | |
| sl1, sl2, sl3: TStringList; | |
| begin | |
| sl1 := nil; | |
| sl2 := TStringList.Create; | |
| sl3 := sl1 or sl2; // -> sl3 = sl2 | |
| end; |
rvelthuis said
The TObjectHelper thing is amazing. It also works on classes, and I already managed to do addition, or to write a helper that gives TStrings an
inoperator. It is simply a cool find.jpluimers said
It’s indeed one of the language additions I like a lot.
sglienke said
It’s a feature by accident – I hope they will add it as an official feature. Some operators are harmless to introduce for classes also on non ARC. Also introducing operator overloads per helper is a good thing and should be supported officially rather than having to use some compiler glitch.