[Development] Future of java-style iterators?
Hi, Some days ago we got an error report in the forum about QHashIterator, turned out to be a missing documentation for a complete class which remained unnoticed since Qt 6.0 (https://bugreports.qt.io/browse/QTBUG-119461). This leads to the question if we should deprecate all java-style iterators since they seem to be a) not widely used and b) it looks like we don't support them in a way we should. What do you think? Cheers, Christian -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Hello, On 03/12/2023 21:56, Christian Ehrlicher wrote: Some days ago we got an error report in the forum about QHashIterator, turned out to be a missing documentation for a complete class which remained unnoticed since Qt 6.0 (https://bugreports.qt.io/browse/QTBUG-119461). This leads to the question if we should deprecate all java-style iterators since they seem to be a) not widely used and b) it looks like we don't support them in a way we should. What do you think? While any "serious" code should build under QT_NO_JAVA_STYLE_ITERATORS¹, how much maintenance do they cost us? There's been virtually 0 changes on them since Qt 6.0. ¹ We should of course open the chapter of having something that defines all these QOL macros. No one should be using the Java iterators. Here's a draft: https://codereview.qt-project.org/c/qt/qtbase/+/522833 My 2 c, -- Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer KDAB (France) S.A.S., a KDAB Group company Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com KDAB - The Qt, C++ and OpenGL Experts smime.p7s Description: S/MIME Cryptographic Signature -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
While I do not use them, I feel that deprecating such core functionality of a framework without measurable gain would seriously harm anyone using them and, most importantly, fundamentally harm the promise and dependability of Qt as a framework of choice. > Giuseppe D'Angelo via Development kirjoitti > 3.12.2023 kello 23.35: > > Hello, > >> On 03/12/2023 21:56, Christian Ehrlicher wrote: >> Some days ago we got an error report in the forum about QHashIterator, >> turned out to be a missing documentation for a complete class which >> remained unnoticed since Qt 6.0 >> (https://bugreports.qt.io/browse/QTBUG-119461). >> This leads to the question if we should deprecate all java-style >> iterators since they seem to be a) not widely used and b) it looks like >> we don't support them in a way we should. >> What do you think? > > While any "serious" code should build under QT_NO_JAVA_STYLE_ITERATORS¹, how > much maintenance do they cost us? There's been virtually 0 changes on them > since Qt 6.0. > > ¹ We should of course open the chapter of having something that defines all > these QOL macros. No one should be using the Java iterators. Here's a draft: > https://codereview.qt-project.org/c/qt/qtbase/+/522833 > > My 2 c, > -- > Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer > KDAB (France) S.A.S., a KDAB Group company > Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com > KDAB - The Qt, C++ and OpenGL Experts > > -- > Development mailing list > Development@qt-project.org > https://lists.qt-project.org/listinfo/development -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
On 04.12.23 09:06, Jyrki Yli-Nokari wrote: > > While I do not use them, I feel that deprecating such core functionality of a > framework without measurable gain would seriously harm anyone using them and, > most importantly, fundamentally harm the promise and dependability of Qt as a > framework of choice. Only if you insist on compiling with deprecation warnings enabled. No-one forces you to do that. We need a way to inform (or even prevent) new users from using such APIs while still allowing existing users to continue to use them. That's what deprecations are for. If you know of a better mechanism, I'm all ears. Until then, either you want to be notified of sub-optimal APIs asap, then you enable deprecation warnings with the intent to fix them, or you don't, then you don't, and fix once every decade when a new Qt major release comes out. Thanks, Marc >> Giuseppe D'Angelo via Development kirjoitti >> 3.12.2023 kello 23.35: >> >> Hello, >> >>> On 03/12/2023 21:56, Christian Ehrlicher wrote: >>> Some days ago we got an error report in the forum about QHashIterator, >>> turned out to be a missing documentation for a complete class which >>> remained unnoticed since Qt 6.0 >>> (https://bugreports.qt.io/browse/QTBUG-119461). >>> This leads to the question if we should deprecate all java-style >>> iterators since they seem to be a) not widely used and b) it looks like >>> we don't support them in a way we should. >>> What do you think? >> >> While any "serious" code should build under QT_NO_JAVA_STYLE_ITERATORS¹, how >> much maintenance do they cost us? There's been virtually 0 changes on them >> since Qt 6.0. >> >> ¹ We should of course open the chapter of having something that defines all >> these QOL macros. No one should be using the Java iterators. Here's a draft: >> https://codereview.qt-project.org/c/qt/qtbase/+/522833 >> >> My 2 c, >> -- >> Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer >> KDAB (France) S.A.S., a KDAB Group company >> Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com/ >> KDAB - The Qt, C++ and OpenGL Experts >> >> -- >> Development mailing list >> Development@qt-project.org >> https://lists.qt-project.org/listinfo/development -- Marc Mutz Principal Software Engineer The Qt Company Erich-Thilo-Str. 10 12489 Berlin, Germany http://www.qt.io/ Geschäftsführer: Mika Pälsi, Juha Varelius, Jouni Lintunen Sitz der Gesellschaft: Berlin, Registergericht: Amtsgericht Charlottenburg, HRB 144331 B -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Fair enough, as long as they are not removed anytime soon > Marc Mutz via Development kirjoitti 4.12.2023 > kello 10.20: > > On 04.12.23 09:06, Jyrki Yli-Nokari wrote: >> >> While I do not use them, I feel that deprecating such core functionality of >> a framework without measurable gain would seriously harm anyone using them >> and, most importantly, fundamentally harm the promise and dependability of >> Qt as a framework of choice. > > Only if you insist on compiling with deprecation warnings enabled. > No-one forces you to do that. > > We need a way to inform (or even prevent) new users from using such APIs > while still allowing existing users to continue to use them. That's what > deprecations are for. If you know of a better mechanism, I'm all ears. > > Until then, either you want to be notified of sub-optimal APIs asap, > then you enable deprecation warnings with the intent to fix them, or you > don't, then you don't, and fix once every decade when a new Qt major > release comes out. > > Thanks, > Marc > > Giuseppe D'Angelo via Development kirjoitti 3.12.2023 kello 23.35: >>> >>> Hello, >>> On 03/12/2023 21:56, Christian Ehrlicher wrote: Some days ago we got an error report in the forum about QHashIterator, turned out to be a missing documentation for a complete class which remained unnoticed since Qt 6.0 (https://bugreports.qt.io/browse/QTBUG-119461). This leads to the question if we should deprecate all java-style iterators since they seem to be a) not widely used and b) it looks like we don't support them in a way we should. What do you think? >>> >>> While any "serious" code should build under QT_NO_JAVA_STYLE_ITERATORS¹, >>> how much maintenance do they cost us? There's been virtually 0 changes on >>> them since Qt 6.0. >>> >>> ¹ We should of course open the chapter of having something that defines all >>> these QOL macros. No one should be using the Java iterators. Here's a draft: >>> https://codereview.qt-project.org/c/qt/qtbase/+/522833 >>> >>> My 2 c, >>> -- >>> Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer >>> KDAB (France) S.A.S., a KDAB Group company >>> Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com/ >>> KDAB - The Qt, C++ and OpenGL Experts >>> >>> -- >>> Development mailing list >>> Development@qt-project.org >>> https://lists.qt-project.org/listinfo/development > -- > Marc Mutz > Principal Software Engineer > > The Qt Company > Erich-Thilo-Str. 10 12489 > Berlin, Germany > http://www.qt.io/ > > Geschäftsführer: Mika Pälsi, Juha Varelius, Jouni Lintunen > Sitz der Gesellschaft: Berlin, > Registergericht: Amtsgericht Charlottenburg, > HRB 144331 B > > -- > Development mailing list > Development@qt-project.org > https://lists.qt-project.org/listinfo/development -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Marc Mutz via Development wrote: > Until then, either you want to be notified of sub-optimal APIs asap, What is "suboptimal" about Java-style iterators, other than that they do not work the same way as the STL ones? I find the Java-style iterators to be easier to use and less error-prone than the STL-style ones (which, as I understand it, is why they were originally added to Qt to begin with). Kevin Kofler -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Il 05/12/23 03:52, Kevin Kofler via Development ha scritto: Marc Mutz via Development wrote: Until then, either you want to be notified of sub-optimal APIs asap, What is "suboptimal" about Java-style iterators, other than that they do not work the same way as the STL ones? I find the Java-style iterators to be easier to use and less error-prone than the STL-style ones (which, as I understand it, is why they were originally added to Qt to begin with). The huge downside is that they don't work with any algorithms or range-based facilities. They work, in their little bubble. My 2 c, -- Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer KDAB (France) S.A.S., a KDAB Group company Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com KDAB - Trusted Software Excellence smime.p7s Description: Firma crittografica S/MIME -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
On 05.12.23 10:06, Giuseppe D'Angelo via Development wrote: > Il 05/12/23 03:52, Kevin Kofler via Development ha scritto: >> Marc Mutz via Development wrote: >>> Until then, either you want to be notified of sub-optimal APIs asap, >> What is "suboptimal" about Java-style iterators, other than that they >> do not >> work the same way as the STL ones? I find the Java-style iterators to be >> easier to use and less error-prone than the STL-style ones (which, as I >> understand it, is why they were originally added to Qt to begin with). > > The huge downside is that they don't work with any algorithms or > range-based facilities. They work, in their little bubble. Const ones are ok-ish, except they need to maintain two iterators instead of one, like STL ones, and the state depends on the history (specifically, whether next() or previous() was called). The problem is the Mutable ones. Which element does setValue() work on? Which one does remove() remove? I don't want to look it up, but I remember there was some conceptional problem there. Also, remove() in a loop is quadratic, and since no-one ever made Java-style iterators for C arrays and STL containers, and they hard-code the name of the container in the class name without containers providing a typedef for them, they cannot possibly be used in generic code. Thanks, Marc -- Marc Mutz Principal Software Engineer The Qt Company Erich-Thilo-Str. 10 12489 Berlin, Germany www.qt.io Geschäftsführer: Mika Pälsi, Juha Varelius, Jouni Lintunen Sitz der Gesellschaft: Berlin, Registergericht: Amtsgericht Charlottenburg, HRB 144331 B -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Hi, would QDirIterator[1] be part of this deprecation? Its API clearly seems be inspired by the Java-style iterators. While I do not care much about the other Java-style iterators, I really like this iterator and use it a lot. What would be this iterator's modern replacement in Qt? Ciao Mathias [1] https://doc.qt.io/qt-6/qdiriterator.html Am 03.12.2023 um 21:56 schrieb Christian Ehrlicher: Hi, Some days ago we got an error report in the forum about QHashIterator, turned out to be a missing documentation for a complete class which remained unnoticed since Qt 6.0 (https://bugreports.qt.io/browse/QTBUG-119461). This leads to the question if we should deprecate all java-style iterators since they seem to be a) not widely used and b) it looks like we don't support them in a way we should. What do you think? Cheers, Christian -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
How about QDir::iterator, QDir::cbegin, basically make QDir a container? Or make a new class that serves the same purpose… /me likes the QDir idea.. :-) Andreas Tir 5 des 2023 kl. 22:15 skrev Mathias Hasselmann via Development: > Hi, > > would QDirIterator[1] be part of this deprecation? Its API clearly seems > be inspired by the Java-style iterators. > > While I do not care much about the other Java-style iterators, I really > like this iterator and use it a lot. > What would be this iterator's modern replacement in Qt? > > Ciao > Mathias > > [1] https://doc.qt.io/qt-6/qdiriterator.html > > Am 03.12.2023 um 21:56 schrieb Christian Ehrlicher: > > Hi, > > > > Some days ago we got an error report in the forum about QHashIterator, > > turned out to be a missing documentation for a complete class which > > remained unnoticed since Qt 6.0 > > (https://bugreports.qt.io/browse/QTBUG-119461). > > This leads to the question if we should deprecate all java-style > > iterators since they seem to be a) not widely used and b) it looks like > > we don't support them in a way we should. > > What do you think? > > > > > > Cheers, > > Christian > > > > > -- > Development mailing list > Development@qt-project.org > https://lists.qt-project.org/listinfo/development > -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
https://code.qt.io/cgit/qt-creator/qt-creator.git/tree/src/libs/utils/filesearch.h FileContainer & FileContainerIterator could be an inspiration, too. The SubDirFileContainer enables traversal according to the selected filters and exclusion filters. This all is a part of the Utils lib inside QtCreator. Jarek From: Development on behalf of Andreas Aardal Hanssen Sent: Tuesday, December 5, 2023 10:26 PM To: Qt Development Subject: Re: [Development] Future of java-style iterators? How about QDir::iterator, QDir::cbegin, basically make QDir a container? Or make a new class that serves the same purpose… /me likes the QDir idea.. :-) Andreas Tir 5 des 2023 kl. 22:15 skrev Mathias Hasselmann via Development: Hi, would QDirIterator[1] be part of this deprecation? Its API clearly seems be inspired by the Java-style iterators. While I do not care much about the other Java-style iterators, I really like this iterator and use it a lot. What would be this iterator's modern replacement in Qt? Ciao Mathias [1] https://doc.qt.io/qt-6/qdiriterator.html Am 03.12.2023 um 21:56 schrieb Christian Ehrlicher: > Hi, > > Some days ago we got an error report in the forum about QHashIterator, > turned out to be a missing documentation for a complete class which > remained unnoticed since Qt 6.0 > (https://bugreports.qt.io/browse/QTBUG-119461). > This leads to the question if we should deprecate all java-style > iterators since they seem to be a) not widely used and b) it looks like > we don't support them in a way we should. > What do you think? > > > Cheers, > Christian > > -- Development mailing list Development@qt-project.org<mailto:Development@qt-project.org> https://lists.qt-project.org/listinfo/development -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
Hello, Il 05/12/23 22:15, Mathias Hasselmann via Development ha scritto: would QDirIterator[1] be part of this deprecation? Its API clearly seems be inspired by the Java-style iterators. While I do not care much about the other Java-style iterators, I really like this iterator and use it a lot. What would be this iterator's modern replacement in Qt? Some classes still only have Java-like iterators, not STL-like, so it would not make sense to deprecate them there. QDirIterator, QRegularExpressionMatchIterator, (private) QStringIterator and similar don't have replacements yet. Yes, one can wrap a Java iterator back into a range API (as I've done for QREMI, so you can use do `for (auto match : re.globalMatch(subj)`), but then one really wants C++20 for the algorithms. Thank you, -- Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer KDAB (France) S.A.S., a KDAB Group company Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com KDAB - Trusted Software Excellence smime.p7s Description: Firma crittografica S/MIME -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
Re: [Development] Future of java-style iterators?
On Tuesday, 5 December 2023 14:02:36 PST Giuseppe D'Angelo via Development wrote: > QDirIterator, QRegularExpressionMatchIterator, (private) QStringIterator > and similar don't have replacements yet. > > Yes, one can wrap a Java iterator back into a range API (as I've done > for QREMI, so you can use do `for (auto match : re.globalMatch(subj)`), > but then one really wants C++20 for the algorithms. QDirIterator could be rewritten either as an input or a forward Standard Library iterator. It wouldn't be a bad idea because its implementation is broken: while you're trying to get the information about the current item, it's stat()ing the next. It's also hard to guess which element you're getting and whether you're accidentally skipping the first entry, or missing the last one. All of which are caused by the fact that it *is* a Java-style iterator. -- Thiago Macieira - thiago.macieira (AT) intel.com Cloud Software Architect - Intel DCAI Cloud Engineering smime.p7s Description: S/MIME cryptographic signature -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
