<div dir="ltr">I don't want this to come across as though I'm trying to shut down discussion (because it's not my place to do so), but a significant amount of time was spent during the Swift 4 design phases debating how access levels should work, decisions were made, and I think many of us would like to move on and give time to other topics.<div><br></div><div>I'd encourage you to look back through the archives and familiarize yourselves with the points made during that time. While it's always possible, I think it's unlikely that there will be new evidence introduced that would be so strong as to give the Swift team reason to, once again, make major source-breaking changes to access levels as late as Swift 5.</div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr">On Thu, Sep 28, 2017 at 5:31 PM Jonathan Hull 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">+1000<div><br></div><div>This is the way it always should have worked… and it is the way my brain still expects it to work. All of the extraneous “Public”s clutter the code and make it much more difficult to read. Without it, the relatively few properties marked Internal or Private stand out.</div><div><br></div><div>I know there is the argument about making people think about whether they want to expose each item… but it doesn’t work that way. Once you assign someone a rote task (assigning Public to most of the things), you lose the effect of having them think. From a cognitive psychology lens, when you give the brain a number of decisions to make in a row that are very similar, it will naturally make that task more efficient by automating as much of it as possible (i.e. thinking about it less). Mistakes become much more likely as a result.</div><div><br></div><div>Tl;dr: <b> </b>Despite the<b> myth</b>/intention<b> </b>that the current setup makes you<b> think about the problem more,</b> it actually does the<b> opposite</b> and leads to an <b>increased risk of error</b>.</div><div><br></div><div>Thanks,</div><div>Jon</div></div><div style="word-wrap:break-word"><div><br></div><div><br><div><blockquote type="cite"><div>On Sep 28, 2017, at 10:44 AM, James Valaitis via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br class="m_-8011517302153124232Apple-interchange-newline"><div><div>When declaring a public class or struct the properties still default to internal.<br>```<br>public final class NewType {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// This property defaults to internal.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>var property: Any?<br>}<br>```<br><br>This is not the same for a public extension on the type, where then the access modifier is respected for any function or calculated property within the extension.<br>```<br>public extension NewType {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// This function inherits the public modifier.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>func function() {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>}<br>}<br>```<br><br>I dislike this inconsistency, and I frequently find that when using my dynamic frameworks my code will not compile, and it will be due to my accidentally writing a public struct but not declaring the properties public.<br><br>I believe in the idea that explicitly stating the access modifier leads to more legible code, but in my opinion it can be overdone, and I much prefer to explicitly state my intentions in the modifier on the definition or extension. For example:<br><br>```<br>public struct Coordinate {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// Should default to public.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>let latitude: Double<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// Should default to public.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>let longitude: Double<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// Should default to public<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>init?(latitude: Double, longitude: Double) {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>guard validate(latitude: latitude, longitude: longitude) else { return nil }<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>…<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>}<br>}<br>internal extension Coordinate {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// Convenience initialiser to me used internally within the module.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>init(coordinate: CLLocationCoordinate2D) {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>…<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>}<br>}<br>private extension Coordinate {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>/// Private validation of the coordinate.<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>func validate(latitude: Double, longitude: Double) -> Bool {<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>…<br><span class="m_-8011517302153124232Apple-tab-span" style="white-space:pre-wrap"> </span>}<br>}<br>```<br><br>This is legible and intuitive. The current behaviour is not.<br><br>_______________________________________________<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></div></blockquote></div><br></div></div>_______________________________________________<br>
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