> On Jun 28, 2016, at 19:03, Matthew Judge <matthew.ju...@gmail.com> wrote: > > Comments inline. > > On Jun 28, 2016, at 04:14, David Hart via swift-evolution > <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: > >> Hello everybody, >> >> I tried using the access rules defined in SE-0025 in some code of mine to >> see what effect it would have. I came out of the experiment more >> disappointed than I thought. Here are several reasons: >> >> 1) The new rules make `private` more prominent compared to `fileprivate` >> (the latter has a somewhat worse name). But at the same time, the Swift >> community has developed a style of coding where a type is defined through a >> set of extensions. To hide members from other types, but have access to them >> inside the type extensions, we have often used `private` and placed the type >> and its extensions in the same file. Because `private` is scoped, we are >> forced into using `fileprivate` pervasively (which is uglier), using >> `internal` instead (which is less safe) or moving the extension code into >> the type's scope (which is against the way Swift code is being written >> today). All of these options look worse to be than before SE-0025. > > If I understand SE-0025 (even with the amendment) you can still spell the > access modifier to types as 'private' and get the same characteristics as the > pre-SE-0025 meaning or private, so I'm not sure I understand the concern > here. However (continued below) >> >> 2) The new amended rules look complicated to me. I think they have the risk >> of being confusing in practice, but we’ll have to see. >> > > I definitely agree that the amended rules look complicated. It seems to me > that the amended set of rules is favoring simplifying the implementation over > simplifying the mental model. > > My impression of what SE-0025 decided was that 'private' meant private to the > enclosing scope. If the access modifying 'private' was applied to a type at > the file scope, then it was synonymous with fileprivate and the default > access of members of that type should be fileprivate. > > If a inner type was declared private, than the default access of members of > that inner type should be private to the Outer type, not fileprivate. There > is currently no way of expressing this access explicitly, but it does not > seem like an especially useful thing to need to spell. > > Said in code, my impression of SE-0025 is that > > private class Outer { // exactly equivalent to fileprivate > var myVar = 0 // default: fileprivate > private class Inner { // private to Outer > var hiddenVar = 0 // default: private to Outer > private var reallyHiddenVar = 0 // default private to Inner > } > }
This is definitely one of the considered alternatives. Both Brent and I didn’t like the idea of an access level that you couldn’t actually spell, and even if we got past that, we’d still need a way to refer to it in documentation and diagnostics. I would count that as a larger change than just allowing ‘fileprivate’ in places that previously would have been called redundant. Jordan
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