<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div><div style="font-family: Calibri,sans-serif; font-size: 11pt;">Goffredo, sorry if it felt offensive. It was not my intention. I've dealt with so many different libraries where, as many already pointed out here, has to rely on "fixing" the library themselves. This is not what a library was supposed to be and I might have left a few of my bad experiences speak louder.<br><br>L</div></div><div dir="ltr"><hr><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">From: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:panajev@gmail.com">Goffredo Marocchi</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Sent: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">07/07/2016 01:39 PM</span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">To: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:me@lmpessoa.com">Leonardo Pessoa</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Cc: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:mailing@xenonium.com">Jean-Daniel Dupas</a>; <a href="mailto:swift-evolution@swift.org">swift-evolution</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Subject: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">Re: [swift-evolution] [Review] SE-0117: Default classes to benon-subclassable publicly</span><br><br></div><div>I disagree that a stable for over 30 years of every OOP language that I know is equivalent to lack of care for good library design, but if we want to push value types by making working with classes harder so be it :P. </div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">Seriously though</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"><blockquote type="cite"><font color="#000000"><span style="background-color: rgba(255, 255, 255, 0);">Mine is the opinion of a library-maker,<br>yours of the user of poorly designed/developed libraries.</span></font></blockquote><div id="AppleMailSignature"><br></div>this kind of attitude on this list got to stop.<br><br>Sent from my iPhone</div><div><br>On 7 Jul 2016, at 17:23, Leonardo Pessoa via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><span>Jean, IMO marking every class as subclassable means the creator does</span><br><span>not care for you to design and develop a great library because s/he is</span><br><span>not caring for the library at all. I right now have to go through the</span><br><span>burdensome activity of marking too many classes/methods as final to</span><br><span>prevent misuse of my libraries and find good design workarounds when I</span><br><span>need to subclass internally what I don't want you to subclass.</span><br><span></span><br><span>IMO the usage of a library is to be crafted/planned/designed by their</span><br><span>developers not their users. Mine is the opinion of a library-maker,</span><br><span>yours of the user of poorly designed/developed libraries. By pushing</span><br><span>this proposal, developer of such libraries will have much burden to</span><br><span>make/keep a poor library or will have to work on better</span><br><span>design/implementation for it to suit its purpose.</span><br><span></span><br><span>L</span><br><span></span><br><span>On 7 July 2016 at 13:08, Jean-Daniel Dupas via swift-evolution</span><br><span><<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:</span><br><blockquote type="cite"><span> * What is your evaluation of the proposal?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Strong -1 too.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>I can’t count the number of times it save my hours tone able to override</span><br></blockquote><blockquote type="cite"><span>arbitrary classes and methods.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Sometimes to simply add log point to understand how the API work. Other</span><br></blockquote><blockquote type="cite"><span>times to workaround bugs in the library. Or even to extends the library in a</span><br></blockquote><blockquote type="cite"><span>way that the author did not intent in the first place, but that was</span><br></blockquote><blockquote type="cite"><span>perfectly supported anyway.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>I already see how libraries author will react to that new default. They will</span><br></blockquote><blockquote type="cite"><span>either don’t care and mark all classes as subclassable, or find to</span><br></blockquote><blockquote type="cite"><span>burdensome to get subclassability right and prohibit subclassing all</span><br></blockquote><blockquote type="cite"><span>classes.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Le 7 juil. 2016 à 02:27, Jonathan Hull via swift-evolution</span><br></blockquote><blockquote type="cite"><span><<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> a écrit :</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>* What is your evaluation of the proposal?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>A **strong** -1</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>First, I have often found that you can’t always predict the way which</span><br></blockquote><blockquote type="cite"><span>something will need to be extended. You think you know, but are then</span><br></blockquote><blockquote type="cite"><span>surprised by creative uses. My favorite features of Swift/Cocoa involve</span><br></blockquote><blockquote type="cite"><span>retroactive modeling.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Second, I don’t think this proposal will achieve its stated objective of</span><br></blockquote><blockquote type="cite"><span>forcing people to think about subclassing more. It will just add confusing</span><br></blockquote><blockquote type="cite"><span>boilerplate.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Things like Swift optionals work well because they make the (often</span><br></blockquote><blockquote type="cite"><span>forgotten) choices explicit in the context that they are used. In the world</span><br></blockquote><blockquote type="cite"><span>of Human Factors, we call it a forcing function. This proposal has the</span><br></blockquote><blockquote type="cite"><span>inverse structure, and will be ineffective, because the “forcing” part of it</span><br></blockquote><blockquote type="cite"><span>shows up in a different context (i.e. trying to use a framework) than the</span><br></blockquote><blockquote type="cite"><span>decision is being made in (writing the framework). This type of thinking</span><br></blockquote><blockquote type="cite"><span>leads to things like Java and the DMV.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>As Tino said:</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>No matter what the defaults are, good libraries are hard to build, so I</span><br></blockquote><blockquote type="cite"><span>predict this proposal would not only fail in increasing framework quality,</span><br></blockquote><blockquote type="cite"><span>but also will make it much harder for users of those frameworks to work</span><br></blockquote><blockquote type="cite"><span>around their flaws, which are just a natural part of every software.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>I think he is right on here. Those who were prone to be thoughtful about</span><br></blockquote><blockquote type="cite"><span>their design would have been anyway. Those who are not thoughtful about</span><br></blockquote><blockquote type="cite"><span>their design will just leave these annotations off… leaving us with no</span><br></blockquote><blockquote type="cite"><span>recourse to extend/modify classes. When people complain, they will add the</span><br></blockquote><blockquote type="cite"><span>annotations without actually thinking about the meaning (i.e. stack overflow</span><br></blockquote><blockquote type="cite"><span>/ the fixit tells me I need to add this word to make the compiler happy).</span><br></blockquote><blockquote type="cite"><span>All this does is put framework users at the mercy of the framework writers.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Finally, this proposal is missing important aspects of the problem space.</span><br></blockquote><blockquote type="cite"><span>If we truly want to solve the issue of subclassing, we need to consider all</span><br></blockquote><blockquote type="cite"><span>of the common issues which arise. Looking at the cocoa documentation you</span><br></blockquote><blockquote type="cite"><span>will see several types of annotations:</span><br></blockquote><blockquote type="cite"><span>1) This method MUST be overridden</span><br></blockquote><blockquote type="cite"><span>2) This method should NOT be overridden</span><br></blockquote><blockquote type="cite"><span>3) This method MUST be called</span><br></blockquote><blockquote type="cite"><span>3) This method should NOT be called except by subclasses</span><br></blockquote><blockquote type="cite"><span>4) This method should NOT be called except by a method override calling</span><br></blockquote><blockquote type="cite"><span>super</span><br></blockquote><blockquote type="cite"><span>5) This method MUST call super</span><br></blockquote><blockquote type="cite"><span>6) Overrides of this method should NOT call super</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>If we are attempting to bring thoughtfulness to the design of classes, I</span><br></blockquote><blockquote type="cite"><span>would like to see things be extendable by default, but with annotations that</span><br></blockquote><blockquote type="cite"><span>thoughtful framework designers can use to designate how a particular method</span><br></blockquote><blockquote type="cite"><span>should be used. In most cases, it should not explicitly forbid the end user</span><br></blockquote><blockquote type="cite"><span>from subclassing, but require them to acknowledge that what they are doing</span><br></blockquote><blockquote type="cite"><span>is not intended by the framework. (e.g. "unsafe override func"…). That</span><br></blockquote><blockquote type="cite"><span>would feel 1000x more swifty to me. Opt-out safety.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>* Is the problem being addressed significant enough to warrant a change to</span><br></blockquote><blockquote type="cite"><span>Swift?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>No. It doesn’t actually solve the problem... and I haven’t actually run into</span><br></blockquote><blockquote type="cite"><span>this problem in the real world.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>* Does this proposal fit well with the feel and direction of Swift?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>No, it gives Swift more of a feeling of busywork and unnecessary boilerplate</span><br></blockquote><blockquote type="cite"><span>while failing to achieve its objective. It goes against the retroactive</span><br></blockquote><blockquote type="cite"><span>modeling allowed by other areas of Swift.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>* If you have used other languages or libraries with a similar feature, how</span><br></blockquote><blockquote type="cite"><span>do you feel that this proposal compares to those?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>I tend to avoid languages which require this sort of thing. In other</span><br></blockquote><blockquote type="cite"><span>languages that lock things down, there is a need to unlock things soon after</span><br></blockquote><blockquote type="cite"><span>(e.g. friend classes).</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>I predict the same thing will happen here. People will quickly be asking</span><br></blockquote><blockquote type="cite"><span>for the ability to patch/override in cases where the framework designer was</span><br></blockquote><blockquote type="cite"><span>wrong. That shows a problem inherent with the design...</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>* How much effort did you put into your review? A glance, a quick reading,</span><br></blockquote><blockquote type="cite"><span>or an in-depth study?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Read the proposal & discussion. Read earlier discussions around access</span><br></blockquote><blockquote type="cite"><span>control that touched on this subject as well. I have been designing</span><br></blockquote><blockquote type="cite"><span>frameworks for years.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Thanks,</span><br></blockquote><blockquote type="cite"><span>Jon</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Hello Swift community,</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>The review of "SE-0117: Default classes to be non-subclassable publicly"</span><br></blockquote><blockquote type="cite"><span>begins now and runs through July 11. The proposal is available here:</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span> <a href="https://github.com/apple/swift-evolution/blob/master/proposals/0117-non-public-subclassable-by-default.md">https://github.com/apple/swift-evolution/blob/master/proposals/0117-non-public-subclassable-by-default.md</a></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Reviews are an important part of the Swift evolution process. All reviews</span><br></blockquote><blockquote type="cite"><span>should be sent to the swift-evolution mailing list at</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span> <a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>or, if you would like to keep your feedback private, directly to the review</span><br></blockquote><blockquote type="cite"><span>manager.</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>What goes into a review?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>The goal of the review process is to improve the proposal under review</span><br></blockquote><blockquote type="cite"><span>through constructive criticism and contribute to the direction of Swift.</span><br></blockquote><blockquote type="cite"><span>When writing your review, here are some questions you might want to answer</span><br></blockquote><blockquote type="cite"><span>in your review:</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span> * What is your evaluation of the proposal?</span><br></blockquote><blockquote type="cite"><span> * Is the problem being addressed significant enough to warrant a change to</span><br></blockquote><blockquote type="cite"><span>Swift?</span><br></blockquote><blockquote type="cite"><span> * Does this proposal fit well with the feel and direction of Swift?</span><br></blockquote><blockquote type="cite"><span> * If you have used other languages or libraries with a similar feature, how</span><br></blockquote><blockquote type="cite"><span>do you feel that this proposal compares to those?</span><br></blockquote><blockquote type="cite"><span> * How much effort did you put into your review? A glance, a quick reading,</span><br></blockquote><blockquote type="cite"><span>or an in-depth study?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>More information about the Swift evolution process is available at</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span> <a href="https://github.com/apple/swift-evolution/blob/master/process.md">https://github.com/apple/swift-evolution/blob/master/process.md</a></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Thank you,</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>-Chris Lattner</span><br></blockquote><blockquote type="cite"><span>Review Manager</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>_______________________________________________</span><br></blockquote><blockquote type="cite"><span>swift-evolution mailing list</span><br></blockquote><blockquote type="cite"><span><a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a></span><br></blockquote><blockquote type="cite"><span><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>_______________________________________________</span><br></blockquote><blockquote type="cite"><span>swift-evolution mailing list</span><br></blockquote><blockquote type="cite"><span><a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a></span><br></blockquote><blockquote type="cite"><span><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><span>_______________________________________________</span><br><span>swift-evolution mailing list</span><br><span><a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a></span><br><span><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></div></blockquote></body></html>