<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div><blockquote type="cite" class=""><div class="">On Mar 26, 2017, at 8:30 AM, Matthew Johnson <<a href="mailto:matthew@anandabits.com" class="">matthew@anandabits.com</a>> wrote:</div><div class=""><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">On Mar 26, 2017, at 4:13 AM, John McCall via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class=""></div><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><div class=""><div class=""><blockquote type="cite" class=""><div class="">On Mar 26, 2017, at 4:27 AM, Goffredo Marocchi <<a href="mailto:panajev@gmail.com" class="">panajev@gmail.com</a>> wrote:</div><div class=""><div dir="auto" class=""><div class="">On 26 Mar 2017, at 06:54, John McCall via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><div class=""><blockquote type="cite" class=""><div class="">On Mar 25, 2017, at 2:11 AM, Carl Brown1 via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><div class=""><div class=""><p class=""><font size="2" class="">Yes, it would change my opinion of it. I wouldn't become a strong supporter because I don't see any value in it, but a rigorous proof that this proposal could not possibly introduce regressions to any existing codebases would change my opinion from "strongly against" to "doesn't matter to me, I'll stop arguing against it and go get my real work done".</font><br class=""></p></div></div></blockquote><div class="">Speaking just for myself, this was a key part of why I was attracted to this proposal: it seemed to me to be extremely unlikely to cause regressions in behavior. Even without any special behavior in the migrator, code will mostly work exactly as before: things that would have been invalid before will become valid, but not the other way around. The exception is that old-private declarations from scopes in the same file can now be found by lookups in different scopes (but still only within the same file). It should be quite straightforward for the migrator to detect when this has happened and report it as something for the programmer to look at. The proposal causes a small regression in functionality, in that there's no longer any way to protect scopes from accesses within the file, but (1) it's okay for Swift to be opinionated about file size and (2) it seems to me that a workable sub-module proposal should solve that more elegantly while simultaneously addressing the concerns of the people who dislike acknowledging the existence of files.</div></div></div></blockquote><div class=""><br class=""></div><div class="">The opinionated flag sometimes, like being Swifty, is being used to swath away disagreement, but opinions should be reasonable and pragmatic too... opinionated as "you will code this way and you will like it" seems hardly ideal too if abused constantly. Programming is a creative endeavour too.</div><div class=""><br class=""></div><div class="">Also, removing a feature that is used and is useful because "maybe" a year or more away there could be a feature that may address the concerns of the people we are stripping away the current feature from seems quite harsh and unfriendly at best... not very logical either.</div></div></div></blockquote><div class=""><br class=""></div><div class="">Scoped-private is not some awesomely expressive feature. It's an access restriction. The "opinion" I'm talking about hardly prevents you from coding however you like. It's just this: organizing your code into smaller, more self-contained components separated by file is good practice anyway, and when you do that, Swift will let you enforce that each component is properly encapsulated.</div></div></div></blockquote><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class=""></div><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">This does not address the case where we have a small helper type that is only 10s of lines long, is not visible outside the file, and encapsulates an important part of the implementation using scoped private. The whole file is usually only a couple hundred lines. This is not an excessively long file and already contains a single component that is presented to the rest of the program.</div></div></blockquote><div><br class=""></div>I acknowledge that this case exists, but by definition, it's a tiny amount of code being "protected" from an almost equally tiny amount of code.</div><div><br class=""></div><div>Access control is primarily communicative. A person who adds unwanted uses of a private property can also just as easily change the access restriction. The point of private access control is to communicate that you've thought about it and that people should think before assuming that it's okay to use something. When you're talking about about tiny amounts of code, that level of communication really is good enough. It has to be, because access control is never going to be sufficiently expressive to express constraints like "this method can only be called from this other method" — we actively would not want to encourage programmers to engage in that level of pedantry, because some of them will, and they'll make themselves miserable and accomplish nothing of value, and they'll blame Swift (correctly) for implying that it was important.</div><div><br class=""></div><div><blockquote type="cite" class=""><div class=""><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">Some designs of submodules might allow us to properly encapsulate everything but if that requires us to put a small helper type in a separate file that would be a very unfortunate and inflexible constraint on how we are able to organize our code. </div><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class=""></div><div style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""> I don't want encapsulation concerns dictating how I physically organize my code. That is significant and unnecessary complexity if you ask me. It forces a tradeoff between desired physical organization and desired encapsulation. We should not force users to make this tradeoff.</div></div></blockquote><div><br class=""></div>See, you say this, and you're apparently talking talking about the burdens of maintaining a 200-line file. Someone else says it, and their files are 10,000 lines long. I'm going to be opinionated and say that, no, physical organization is inherently linked to encapsulation because of the implicit outer scope of the file, and that if you care about encapsulation, you should also be organizing your code to minimize that outer scope, which will also make it trivial to understand how a private declaration is used and recognize in code reviews for changes that touch that file that they're accessing something they shouldn't.</div><div><br class=""></div><div>John.</div><div><br class=""><blockquote type="cite" class=""><div class=""><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><div class=""><div class=""><br class=""></div><div class="">John.</div><div class=""><br class=""><blockquote type="cite" class=""><div class=""><div dir="auto" class=""><br class=""><blockquote type="cite" class=""><div class=""><div class=""><div class=""><br class=""></div><div class="">John.</div><blockquote type="cite" class=""><div class=""><div class=""><p class=""><font size="2" class="">-Carl</font><br class=""><br class=""><span id="cid:1__=8FBB0A7DDFB206B68f9e8a93df938690918c8FB@" class=""><graycol.gif></span><font size="2" color="#424282" class="">Xiaodi Wu ---03/25/2017 12:33:55 AM---Would it change your opinion on the proposal? On Sat, Mar 25, 2017 at 12:10 AM, Carl Brown1 <Carl.Br</font><br class=""><br class=""><font size="2" color="#5F5F5F" class="">From:<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font><font size="2" class="">Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" class="">xiaodi.wu@gmail.com</a>></font><br class=""><font size="2" color="#5F5F5F" class="">To:<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font><font size="2" class="">Carl Brown1/US/IBM@IBM</font><br class=""><font size="2" color="#5F5F5F" class="">Cc:<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font><font size="2" class="">Drew Crawford <<a href="mailto:drew@sealedabstract.com" class="">drew@sealedabstract.com</a>>, Jonathan Hull <<a href="mailto:jhull@gbis.com" class="">jhull@gbis.com</a>>, swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>></font><br class=""><font size="2" color="#5F5F5F" class="">Date:<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font><font size="2" class="">03/25/2017 12:33 AM</font><br class=""><font size="2" color="#5F5F5F" class="">Subject:<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font><font size="2" class="">Re: [swift-evolution] [Review] SE-0159: Fix Private Access Levels</font><br class=""></p><hr width="100%" size="2" align="left" noshade="" class="" style="color: rgb(128, 145, 165);"><br class=""><br class=""><br class="">Would it change your opinion on the proposal?<br class=""><br class=""><br class="">On Sat, Mar 25, 2017 at 12:10 AM, Carl Brown1 <<a href="mailto:Carl.Brown1@ibm.com" target="_blank" class=""><u class=""><font color="#0000FF" class="">Carl.Brown1@ibm.com</font></u></a>> wrote:<ul class=""><font size="2" class="">I would very much like to see your proof that the resultant code is unchanged in an arbitrary codebase.<span class="Apple-converted-space"> </span></font><br class=""><font size="2" class=""><br class="">-Carl</font><br class=""><br class=""><span id="cid:1__=8FBB0A7DDFB206B68f9e8a93df938690918c8FB@" class=""><graycol.gif></span><font size="2" color="#424282" class="">Xiaodi Wu ---03/25/2017 12:01:26 AM---On Fri, Mar 24, 2017 at 11:55 PM, Carl Brown1 <</font><a href="mailto:Carl.Brown1@ibm.com" target="_blank" class=""><u class=""><font size="2" color="#0000FF" class="">Carl.Brown1@ibm.com</font></u></a><font size="2" color="#424282" class="">> wrote: > Maybe this is the core</font><br class=""><font size="2" color="#5F5F5F" class=""><br class="">From:<span class="Apple-converted-space"> </span></font><font size="2" class="">Xiaodi Wu <</font><a href="mailto:xiaodi.wu@gmail.com" target="_blank" class=""><u class=""><font size="2" color="#0000FF" class="">xiaodi.wu@gmail.com</font></u></a><font size="2" class="">></font><font size="2" color="#5F5F5F" class=""><br class="">To:<span class="Apple-converted-space"> </span></font><font size="2" class="">Carl Brown1/US/IBM@IBM</font><font size="2" color="#5F5F5F" class=""><br class="">Cc:<span class="Apple-converted-space"> </span></font><font size="2" class="">Drew Crawford <</font><a href="mailto:drew@sealedabstract.com" target="_blank" class=""><u class=""><font size="2" color="#0000FF" class="">drew@sealedabstract.com</font></u></a><font size="2" class="">>, Jonathan Hull <</font><a href="mailto:jhull@gbis.com" target="_blank" class=""><u class=""><font size="2" color="#0000FF" class="">jhull@gbis.com</font></u></a><font size="2" class="">>, swift-evolution <</font><a href="mailto:swift-evolution@swift.org" target="_blank" class=""><u class=""><font size="2" color="#0000FF" class="">swift-evolution@swift.org</font></u></a><font size="2" class="">></font><font size="2" color="#5F5F5F" class=""><br class="">Date:<span class="Apple-converted-space"> </span></font><font size="2" class="">03/25/2017 12:01 AM</font><font size="2" color="#5F5F5F" class=""><br class="">Subject:<span class="Apple-converted-space"> </span></font><font size="2" class="">Re: [swift-evolution] [Review] SE-0159: Fix Private Access Levels</font><br class=""><hr width="100%" size="2" align="left" noshade="" class=""><br class=""><br class=""><br class="">On Fri, Mar 24, 2017 at 11:55 PM, Carl Brown1 <<a href="mailto:Carl.Brown1@ibm.com" target="_blank" class=""><u class=""><font color="#0000FF" class="">Carl.Brown1@ibm.com</font></u></a>> wrote:<span class="Apple-converted-space"> </span><p class="">My point is that, in rolling back the specific portion of SE-0025, case-sensitive find-and-replace will be the trickiest thing in most codebases, save those that result in invalid redeclarations. The behavior of the resultant code is, unless I'm mistaken, provably unchanged.</p><div class=""><br class="webkit-block-placeholder"></div></ul><br class=""><div class=""><br class="webkit-block-placeholder"></div><p class=""><br class=""></p></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></blockquote><blockquote type="cite" class=""><div class=""><span class="">_______________________________________________</span><br class=""><span class="">swift-evolution mailing list</span><br class=""><span class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a></span><br class=""><span class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br class=""></div></blockquote></div></div></blockquote></div><br class=""></div></blockquote><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><div class=""><span class="">_______________________________________________</span><br class=""><span class="">swift-evolution mailing list</span><br class=""><span class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a></span><br class=""><span class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span></div></blockquote></div></blockquote></div><br class=""></body></html>