[Issue 3258] Calling private or package override methods calls the base implementation
https://issues.dlang.org/show_bug.cgi?id=3258 RazvanN changed: What|Removed |Added Status|NEW |RESOLVED CC||razvan.nitu1...@gmail.com Resolution|--- |FIXED --- Comment #14 from RazvanN --- Code fails to compile in D2 git master stating that private and package members cannot be overridden. Closing as FIXED. --
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #12 from Diggory diggory.ha...@gmail.com 2012-12-22 02:26:22 PST --- (In reply to comment #11) (In reply to comment #10) I forgot one thing that completes the circle, and that is friend declarations. There are no friend declarations in D. So what exactly are you talking about? Look up friend classes/functions in C++ and his meaning should be clear. For the problem at hand though, without causing a lot of breakage, that means either private/package become virtual by default, private/package can never be virtual, or a 'virtual' (or 'overridable') keyword is introduced. In theory I agree with Andrej, but would probably vote that handling all protection methods in the same way is preferable. In an ideal world though, I think I'd choose to make overriding explicit and shadowing illegal: i.e. unless 'virtual'/'override' is specified names must not clash with those from a base class. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #13 from Stewart Gordon s...@iname.com 2012-12-22 03:56:58 PST --- (In reply to comment #12) For the problem at hand though, without causing a lot of breakage, that means either private/package become virtual by default, private/package can never be virtual, or a 'virtual' (or 'overridable') keyword is introduced. In theory I agree with Andrej, but would probably vote that handling all protection methods in the same way is preferable. At the moment, we have final, which is roughly the negation of virtual. In an ideal world though, I think I'd choose to make overriding explicit and shadowing illegal: i.e. unless 'virtual'/'override' is specified names must not clash with those from a base class. I agree that it would be a way forward to kill overriding without the override attribute once and for all. Once this is done, we can implement this principle: - If a private symbol is redeclared in a subclass in the same module, it must have the override attribute, and it overrides the superclass method. - If a private symbol is redeclared in a subclass in a different module, it must not have the override attribute, and the two are distinct symbols with no relation to each other. Basically, the subclass has no knowledge of the superclass's private members (as it should be). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Andrej Mitrovic andrej.mitrov...@gmail.com changed: What|Removed |Added CC||andrej.mitrov...@gmail.com Version|D1 D2 |D1 --- Comment #6 from Andrej Mitrovic andrej.mitrov...@gmail.com 2012-12-21 10:39:11 PST --- I don't know the state of D1 but in D2 these overloads are flagged as errors, so I'm removing D2 from the list. As for non-virtual private/package - this should be an enhancement request, but it's probably been debated many times already (I personally believe access specifiers should not mess with the virtuality of a method). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #7 from Diggory diggory.ha...@gmail.com 2012-12-21 11:19:38 PST --- Andrej, that seems like a funny change to me. Unless D2 either allows virtual package functions or states that these are not allowed it seems that it's still broken to me. The spec says All non-sta�tic non-pri�vate non-tem�plate mem�ber func�tions are vir�tual. which I interpret to include package members. Not that I particularly care any more... -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Jonathan M Davis jmdavisp...@gmx.com changed: What|Removed |Added CC||jmdavisp...@gmx.com --- Comment #8 from Jonathan M Davis jmdavisp...@gmx.com 2012-12-21 11:53:54 PST --- It's been discussed many times, and the spec is wrong in this case (I keep meaning to update it but haven't done so yet). public and protected member functions are _always_ virtual unless the compiler can determine that they're never overridden (which can only happen when they're final). private and package member functions are _never_ virtual. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #9 from Andrej Mitrovic andrej.mitrov...@gmail.com 2012-12-21 15:09:12 PST --- (In reply to comment #7) Yeah I know, the spec tells one thing on one page, then another thing on another. It says Package extends private on the protection attributes page, implying it's final like private. Small note: In terms of the compiler implementation, the private and package set to non-virtual boils down to a single `if` check in the front-end. Forcing private and package non-virtual must have a rationale in the spec. There isn't one, so Walter and Andrei should state exactly why this decision was made. Actually, Walter and Andrei obviously had a miscommunication, because Andrei expected private to allow being virtual in TDPL. And 'package' being non-virtual isn't mentioned in TDPL either (lots of people get confused by this). So maybe Walter is the one to write the rationale. I also believe it's not too late to change the state of things. We have the `final` keyword after all. Yes, making private and package virtual could potentially slow down code, but fixing it is trivial, it just requires a `final` keyword. Perhaps the the compiler can be made smart enough to optimize non-overriden private/package methods so they're made final. Maybe if -lib or -c are not used it can do such optimizations. It's ironic that the argument against private/package being virtual is because of performance reasons when we've already made the mistake of making all methods virtual by default. I *still* can't get used to the fact that a public method is virtual by default, it really lacks that documentation aspect of having a 'virtual' keyword right next to it. And as argumented before, you could easily forget to mark something as 'final' in a library, the user overriding such a method, followed by an API update where you do a bugfix and mark it as final, which ends up breaking the user code. Unfortunately this also becomes an argument against making private/package virtual by default too. Non-virtual by default + a virtual keyword + no limits on virtuality based on access specifiers = dream come true (for me). We're in an odd status-quo, all I can do is sigh at the situation. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #10 from Andrej Mitrovic andrej.mitrov...@gmail.com 2012-12-21 17:04:28 PST --- (In reply to comment #9) Non-virtual by default + a virtual keyword + no limits on virtuality based on access specifiers = dream come true (for me). I forgot one thing that completes the circle, and that is friend declarations. That way private inheritance actually becomes useful beyond the module the class is declared in. I never liked the idea of having private leak into the entire module to begin with, I want fine-grained access via friend declarations and access specifiers which don't mess with virtuality. Otherwise I'm left using PIMPL idioms or mixin templates (yuck!). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #11 from Stewart Gordon s...@iname.com 2012-12-21 17:14:10 PST --- (In reply to comment #10) I forgot one thing that completes the circle, and that is friend declarations. There are no friend declarations in D. So what exactly are you talking about? -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Mike Shulman viritrilbi...@gmail.com changed: What|Removed |Added CC||viritrilbi...@gmail.com --- Comment #5 from Mike Shulman viritrilbi...@gmail.com 2011-06-03 20:48:04 PDT --- Since private methods are visible to the entire module in which they are defined, and thus could reasonably be overridden by derived classes defined in the same module, I don't see why making them all non-virtual is any more valid of an optimization, in principle, than doing the same for package methods. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 --- Comment #3 from Diggory diggory.ha...@gmail.com 2009-08-19 23:14:26 PDT --- With private functions, yes. But I've never heard that package functions can't be virtual. Stewart Gordan, are you saying package functions aren't virtual by design (I hope not), or that this is just the current implementation? -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Jarrett Billingsley jarrett.billings...@gmail.com changed: What|Removed |Added CC||jarrett.billings...@gmail.c ||om --- Comment #4 from Jarrett Billingsley jarrett.billings...@gmail.com 2009-08-19 23:47:28 PDT --- (In reply to comment #3) With private functions, yes. But I've never heard that package functions can't be virtual. Stewart Gordan, are you saying package functions aren't virtual by design (I hope not), or that this is just the current implementation? Whether it's by design or not is not entirely clear. The only thing the spec says about 'package' in this regard is that it is basically an extension of 'private', in which case it makes sense (in a strange way) that 'package' would make a method nonvirtual. But it just seems like it's conflating two entirely different concepts: access and virtuality. Private methods can and should be nonvirtual, since that's a valid optimization. But it's entirely reasonable to have a package method that can be overridden. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Stewart Gordon s...@iname.com changed: What|Removed |Added CC||s...@iname.com --- Comment #1 from Stewart Gordon s...@iname.com 2009-08-19 12:41:34 PDT --- private and package methods aren't virtual and so don't override. There should be something in the spec to this effect, but I can't seem to find it. The bug is that the compiler accepts the override attribute on these, simple as that. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3258] Calling private or package override methods calls the base implementation
http://d.puremagic.com/issues/show_bug.cgi?id=3258 Matti Niemenmaa matti.niemenmaa+dbugzi...@iki.fi changed: What|Removed |Added CC||matti.niemenmaa+dbugzi...@i ||ki.fi --- Comment #2 from Matti Niemenmaa matti.niemenmaa+dbugzi...@iki.fi 2009-08-19 13:32:06 PDT --- http://www.digitalmars.com/d/1.0/attribute.html#ProtectionAttribute says: Private members cannot be overridden. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
