The main argument against seems to be that using “scoped” doesn’t allow putting more code in extensions inside the same file. And the reason to put code into extensions is to group it in some meaningful way, the most common being implementation of a protocol. I completely agree that this is a nice feature, and I wouldn’t want to lose it myself. At the same time, I think that the most important grouping is one that is based on whether something needs access to internal state and can potentially break it. My reasoning:<br><br>- the compiler can help ensure correctness because it won’t let you use unsafe APIs that could break invariants / internal state.<br><br>- changing the implementation is much easier because implementation details are not scattered throughout the file and are isolated in one place (the scope).<br><br>- the tools can (and should) hide the “scoped” elements from the outside and make code completion for the rest of the code much more convenient<br><br>But the more general question is this: are you willing to give up on compiler's help with code correctness for a little more code grouping convenience? This same argument could be made about “private”. Let’s say you have a very large file that you want to break into smaller files, and the code uses “private” throughout the file. If you break it up, you have to remove “private” and make it “internal” and lose the compiler’s’ help with access control. If we go that route, only “public” vs “internal” makes sense. And yet, “private” is there. As it is today, it’s a good alternative to “friend” in C++, but it doesn’t address the problem that “scoped” solves.<br><br><div class="gmail_quote"><div dir="ltr">On Fri, Mar 4, 2016 at 4:12 AM Adrian Kashivskyy via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><blockquote type="cite"><div style="word-wrap:break-word"><div><div><blockquote type="cite">Does this proposal fit well with the feel and direction of Swift?</blockquote><br></div></div><div>Yes and no. Yes, because it a</div></div></blockquote><div><br></div></div><div style="word-wrap:break-word"><div>Sorry, I forgot to finish the sentence. 🙈</div><div><br></div><div></div></div><div style="word-wrap:break-word"><div><div style="word-wrap:break-word"><div><div><blockquote type="cite">Does this proposal fit well with the feel and direction of Swift?</blockquote></div></div></div><div style="word-wrap:break-word"><div><div><br></div></div></div></div></div><div style="word-wrap:break-word"><div><div style="word-wrap:break-word"><div>Yes and no. Yes, because it could in some small percent increase the safety of our programs. No, because it would strip away the "composability" of our code. </div></div></div><div><br></div><div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><font color="#929292"><br>Pozdrawiam – Regards,</font></div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><font color="#929292">Adrian Kashivskyy</font></div>
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<br><div><blockquote type="cite"><div>Wiadomość napisana przez Adrian Kashivskyy via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> w dniu 04.03.2016, o godz. 10:09:</div></blockquote></div></div><div style="word-wrap:break-word"><div><blockquote type="cite"><br><div><div style="word-wrap:break-word"><blockquote type="cite">What is your evaluation of the proposal?</blockquote><div><br></div><div>Neutral. While I agree that scoped access levels can be useful in some cases, I don't see much long-term profits, especially when using a "protocol conformance in an extension" style:</div><div><br></div><div>struct Foo {</div><div><span style="white-space:pre-wrap"> </span>private func doSomethingInternal()</div><div>}</div><div><br></div><div>extension Foo: Barable {</div><div><span style="white-space:pre-wrap"> </span>func bar() {</div><div><span style="white-space:pre-wrap"> </span>doSomethingInternal()</div><div><span style="white-space:pre-wrap"> </span>}</div><div>}</div><div><br></div><div>The above would not be possible to achieve with scoped access levels.</div><div><br></div><div><div><blockquote type="cite">Is the problem being addressed significant enough to warrant a change to Swift?</blockquote><br></div></div><div>I don't think so. File access level does the job well for me.</div><div><br></div><div><div><blockquote type="cite">Does this proposal fit well with the feel and direction of Swift?</blockquote><br></div></div><div>Yes and no. Yes, because it a</div><div><br></div><div><div><blockquote type="cite">If you have used other languages or libraries with a similar feature, how do you feel that this proposal compares to those?</blockquote><br></div></div><div>Yes, Ruby, PHP, C++. In those languages, there are no file access levels and so the scoped access levels are the only ones which allow to hide the implementation details from the outside world. In Swift, however, file access level allows us to do the same with additional bonus – we can use those `private` members in extensions.</div><div><br></div><div><div><blockquote type="cite">How much effort did you put into your review? A glance, a quick reading, or an in-depth study?</blockquote></div></div><div><br></div><div>
<div style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><font color="#929292"><br>Pozdrawiam – Regards,</font></div><div style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><font color="#929292">Adrian Kashivskyy</font></div>
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<br><div><blockquote type="cite"><div>Wiadomość napisana przez Douglas Gregor via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> w dniu 26.02.2016, o godz. 20:05:</div><br><div><div style="word-wrap:break-word"><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">Hello Swift community,</p><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">The review of SE-0025 “Scoped Access Level" begins now and runs through March 3, 2016. The proposal is available here:</p><blockquote style="margin:0px 0px 16px;padding:0px 15px;border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221);background-color:rgb(255,255,255)"><div style="margin-top:0px;margin-bottom:0px"><font color="#777777" face="Helvetica Neue, Helvetica, Segoe UI, Arial, freesans, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol" size="3"><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md" target="_blank">https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md</a></font></div></blockquote><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">Reviews are an important part of the Swift evolution process. All reviews should be sent to the swift-evolution mailing list at</p><blockquote style="margin:0px 0px 16px;padding:0px 15px;color:rgb(119,119,119);border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)"><div style="margin-top:0px;margin-bottom:0px"><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" style="background-color:transparent;color:rgb(64,120,192);text-decoration:none" target="_blank">https://lists.swift.org/mailman/listinfo/swift-evolution</a></div></blockquote><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">or, if you would like to keep your feedback private, directly to the review manager. When replying, please try to keep the proposal link at the top of the message:</p><blockquote style="margin:0px 0px 16px;padding:0px 15px;color:rgb(119,119,119);border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)"><p style="margin-top:0px;margin-bottom:16px">Proposal link:</p><blockquote style="margin:0px 0px 16px;padding:0px 15px;border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221)"><div style="margin-top:0px;margin-bottom:0px"><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md" target="_blank">https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md</a></div></blockquote><p style="margin-top:0px;margin-bottom:16px">Reply text</p><blockquote style="margin:0px;padding:0px 15px;border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221)"><div style="margin-top:0px;margin-bottom:0px">Other replies</div></blockquote></blockquote><h5 style="margin-top:1em;margin-bottom:16px;line-height:1.4;font-size:1em;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';background-color:rgb(255,255,255)"><a href="https://github.com/apple/swift-evolution#what-goes-into-a-review-1" style="background-color:transparent;color:rgb(64,120,192);text-decoration:none;display:inline-block;padding-right:2px;line-height:1.1" target="_blank"><u></u><u></u><u></u><u></u></a>What goes into a review?</h5><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">The goal of the review process is to improve the proposal under review through constructive criticism and, eventually, determine the direction of Swift. When writing your review, here are some questions you might want to answer in your review:</p><ul style="padding:0px 0px 0px 2em;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)"><li>What is your evaluation of the proposal?</li><li>Is the problem being addressed significant enough to warrant a change to Swift?</li><li>Does this proposal fit well with the feel and direction of Swift?</li><li>If you have used other languages or libraries with a similar feature, how do you feel that this proposal compares to those?</li><li>How much effort did you put into your review? A glance, a quick reading, or an in-depth study?</li></ul><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">More information about the Swift evolution process is available at</p><blockquote style="margin:0px 0px 16px;padding:0px 15px;color:rgb(119,119,119);border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)"><div style="margin-top:0px;margin-bottom:0px"><a href="https://github.com/apple/swift-evolution/blob/master/process.md" style="background-color:transparent;color:rgb(64,120,192);text-decoration:none" target="_blank">https://github.com/apple/swift-evolution/blob/master/process.md</a></div></blockquote><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">Thank you,</p><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">-Doug Gregor</p><p style="margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,'Segoe UI',Arial,freesans,sans-serif,'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol';font-size:16px;background-color:rgb(255,255,255)">Review Manager</p></div>_______________________________________________<br>swift-evolution mailing list<br><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br></div></blockquote></div><br></div>_______________________________________________<br>swift-evolution mailing list<br><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br></div></blockquote></div></div>_______________________________________________<br>
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