Thank you for the long reply, I do agree that I could have been more constructive and what I said could have been more on point with the thread at hand and better argued. I do like a complete and well written rebuttal, chance for me to learn from it :).
On Thu, Aug 3, 2017 at 5:14 PM, Austin Zheng <austinzh...@gmail.com> wrote: > > > On Thu, Aug 3, 2017 at 8:13 AM, Goffredo Marocchi <pana...@gmail.com> > wrote: > >> Because what is the current idiomatic Swift of today may not be the Swift >> of tomorrow if people are allowed to keep shaping it as it gets used in the >> real world. Ideas can be imported from other languages and today's ideas >> and philosophy are not dogmas. >> > > The problem I see with your email is that it does not contribute anything > to the discussion. > > - We _know_ Swift has an expressivity problem compared to Objective-C, > many people have made this point loud and clear. > - There are no useful concrete proposals or suggestions of design > directions expressed in this email besides the rehashing of a point that > has been made ad nauseaum on these lists, especially in places more > appropriate for it (e.g. in proposal reviews that involved strengthening > the type system). > > >> Swift does value expressiveness, see the use of argument labels which is >> perhaps more pervasive than it was in Objective-C (even more before the >> change in argument labels that hit closures and callbacks). >> > > Here is the crux of my disagreement with your email. > > Method naming conventions and static typing can be adjusted nearly > independently of one another, and bringing up the latter in a discussion > about the former is _not helpful_. > > You could remove Swift's type system tomorrow and still improve how > methods are named. In fact, Swift's current naming conventions are quite > suited for a dynamic language. You could also strengthen Swift's type > system and improve method naming conventions. The two do not march in > lockstep. "Expressiveness" is a huge, vague, and wide-reaching topic. > Claiming that static typing is an expressiveness concern and therefore that > complaining about it in a thread that deals with an almost completely > unrelated feature strikes me as disingenuous. Help me out here. > > >> >> > >> I do not want to add noise to useful discussions so please do not assume >> the worst in my statements, but I also do not think that the idea of "if >> you do not like <a>, go back to your <insert expletive> country" has merit >> or is helpful to the evolution of the language. >> > > Please. > > The issue at hand is not "go back to your country", it is "use the right > tool for the job at hand". > > Engineering, like every field of human endeavor, has political elements, > but it is not itself a fundamentally political endeavor. This gross > anthropomorphization is beneath both you and I, and is better avoided for > the happiness of all. > > As for contributing to the evolution of the language, your post is not the > first of its quality, specific form, and sentiment that I've seen on the > list, but only the first that I've been moved to respond to. So if I can > steer future discussion in a more productive direction, I will consider > this email chain to be a net positive, even if I have to send out quite a > few more of these emails in reply :). > > With the utmost respect, > Austin > > > > >> On Thu, Aug 3, 2017 at 3:16 PM, Austin Zheng <austinzh...@gmail.com> >> wrote: >> >>> If you want to use Objective-C you're free to use Objective-C, or more >>> generally any of the wonderful languages that choose a different tradeoff >>> regarding convenience over expressiveness. Otherwise, I'm not really sure >>> what productive forward movement bringing up complaints about a fundamental >>> philosophical underpinning of Swift that's not realistically going to >>> change is supposed to achieve. As was mentioned in a message earlier this >>> week, swift-evolution is a list to discuss making changes to the Swift >>> language, not a list for ranting about things in Swift you don't like but >>> cannot change. >>> >>> Regards, >>> Austin >>> >>> On Aug 2, 2017, at 11:43 PM, Goffredo Marocchi via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>> >>> Sent from my iPhone >>> >>> On 3 Aug 2017, at 04:39, Brent Royal-Gordon via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>> On Aug 2, 2017, at 10:49 AM, Xiaodi Wu via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>> Brent had a draft proposal to revise the names of collection methods to >>> improve the situation here. There is room for improvement. >>> >>> >>> It didn't change `remove(at:)`, though. (Well, it might have affected >>> its return value or something, I don't remember.) It mostly addressed the >>> `dropLast()`, `prefix(_:)` etc. calls. >>> >>> To respond to the original post: >>> >>> Some of the APIs you cite are not very well named, but I think your >>> diagnosis is incorrect and so your prescription isn't going to help. >>> >>> The reason for this is, whenever a preposition is used in English, it >>> almost always takes a dyadic form, relating a subject to the preposition's >>> object. The two most common dyadic formats are: >>> >>> *<subject> [<preposition> <object of preposition>]* >>> <The boy> [<with> <the dog>] crossed the street. >>> >>> *[<preposition> <** object of preposition**>] <subject>* >>> [<In> <space>], <no one> can hear you scream. >>> [<On> <the Moon>] are <many craters>. >>> >>> Now, in Objective C through Swift 1 and 2, prepositions' dyadic nature >>> were generally respected in method signatures. However, Swift 3's migration >>> of the preposition inside the parentheses also seems to have been >>> accompanied by the stripping away of either the subject, the prepositional >>> object, or both—according to no discernible pattern. For example: >>> >>> (1) CloudKit: >>> >>> old: myCKDatabase.fetchRecordWithID(recordID) >>> new: myCKDatabase.fetch(withRecordID: recordID) >>> *(subject "Record" got removed)* >>> >>> >>> (2) String: >>> >>> old: myString.capitalizedStringWithLocale(_: myLocale) >>> new: myString.capitalized(with: myLocale) >>> *(subject "String" and prep. object "Locale" both got removed)* >>> >>> >>> (3) Dictionary: >>> >>> old: myDict.removeAtIndex(myIndex) >>> new: myDict.remove(at: myIndex) >>> *(subject "element" already missing from both; prep. object "Index" got >>> removed)* >>> >>> >>> The thing is, the subjects and prepositional objects *are* present in >>> all of these—they are the parameters and targets of the calls. >>> >>> In your own example, you say "In space, no one can hear you scream", not >>> "In location space, group-of-people no one can hear you scream". So why is >>> it a problem that we say "myString, capitalized with myLocale" instead of >>> "myString, string capitalized with locale myLocale"? These are redundancies >>> that we would never tolerate in natural language; I don't see why you think >>> code should be different. >>> >>> (4) Date: >>> >>> old: myDate.timeIntervalSinceDate(myDate) >>> new: myDate.timeIntervalSince(date: myDate) >>> *(subject "timeInterval" and object "Date" both still present; but >>> oddly, preposition "since" got left outside of the parentheses)* >>> >>> >>> This is actually inaccurate—the parameter to `timeIntervalSince(_:)` is >>> unlabeled, so it's: >>> >>> new: myDate.timeIntervalSince(myDate) >>> >>> (5) Array: >>> >>> old: myArray.forEach({ thing in code}) >>> >>> new: myArray.forEach() { thing in //code } >>> >>> *(preposition “for” is outside of the parentheses)* >>> >>> >>> Yes, because the preposition does not apply to the parameter—it applies >>> to the operation as a whole. I'll have more to say on this in a moment. >>> >>> The inconsistency between the examples is shown in the bold text of each >>> example, but lets go over why this matters. It matters because any language >>> is easier to learn the more consistently it sticks to its own rules. >>> >>> >>> This is true, but you aren't just proposing sticking more closely to our >>> existing standards—you're proposing *changing* our standards. And I don't >>> think the changes you propose are an improvement. In fact, I'd say each of >>> these examples is worse: >>> >>> (1) myCKDatabase.fetchRecord(withRecordID:) >>> >>> >>> "Fetch record with record ID"? I mean, you could at least remove the >>> `Record` before `ID`. What other ID do you suppose it would be? >>> >>> I *can* see the case for going back to `fetchRecord` instead of just >>> `fetch`, though. On the other hand, I do think that, if you know it's a >>> database, the most obvious thing for `fetch` to be fetching is a record >>> from that database. It's not a dog—it won't be fetching a stick. >>> >>> (2) myString.stringCapitalized(withLocale:) >>> >>> >>> Let's translate this to an actual use site, which is what we care about. >>> >>> func tableView(_: UITableView, titleForHeaderInSection section: Int) -> >>> String? { >>> return sections[section].title.stringCapitalized(withLocale: .current) >>> } >>> >>> What is `string` contributing here? We already know it's a "title", >>> which sounds a lot like a string. If you asked for a "capitalized" string, >>> what else would you get back if not another string? >>> >>> The locale parameter is a little more tricky. You're right that `(with: >>> .current)` is vague, but I can imagine plenty of call sites where `with` >>> wouldn't be: >>> >>> title.capitalized(with: german) >>> title.capitalized(with: docLocale) >>> title.capitalized(with: otherUser.locale) >>> >>> Something at the call site needs to imply this is a locale, and there's >>> nothing in `(with: .current)` that does so. This is arguably just a style >>> issue, though: even though the language allows you to say `(with: >>> .current)`, you really ought to say `(with: Locale.current)` to be clearer. >>> Or perhaps the problem is with the name `current`—it ought to be >>> `currentLocale` (even though that's redundant when you write it out as >>> `Locale.currentLocale`), or it should use some location-ish terminology >>> like `home` or `native`. >>> >>> (Actually, I think there might be a new guideline there: Variable and >>> property names should at least hint at the type of the value they contain. >>> Names like `current` or `shared` or `default` are too vague, and should >>> usually be paired with a word that implies the type.) >>> >>> It might also help to change the `with` preposition to `in`, which would >>> at least imply that the parameter is related to some kind of location. >>> >>> title.capitalized(in: german) >>> title.capitalized(in: docLocale) >>> title.capitalized(in: otherUser.locale) >>> title.capitalized(in: .current) // Still not great, but better >>> >>> (3) myDictionary.elementRemoved(atIndex:) >>> >>> >>> This naming is exactly backwards, and is a perfect example of why we >>> *don't* want rigid consistency: >>> >>> 1. It emphasizes the element being returned, while making the "Removed" >>> operation an afterthought, even though the removal is the main thing you >>> want to happen and the element is returned as an afterthought. >>> >>> 2. It mentions the "Index", even though there is no other plausible >>> thing that could be labeled "at". (The only other plausible parameters to a >>> `remove` method are an element, an array of elements, a predicate, or a >>> range of indices. Of those four, only the range of indices could possibly >>> make sense with "at", but that ambiguity is a harmless overloading.) >>> >>> Again, think about a use site: >>> >>> func tableView(_: UITableView, commit edit: UITableViewCellEditingStyle, >>> forRowAt indexPath: IndexPath) { >>> assert(edit == .delete) >>> sections[indexPath.section].rows.elementRemoved(atIndex: indexPath.row) >>> // vs. >>> sections[indexPath.section].rows.remove(at: indexPath.row) >>> } >>> >>> In context, `elementRemoved` obscures the purpose of the line, and there >>> is no ambiguity about what `at` means. The current name is *far* better. >>> >>> (4) myDate.timeInterval(sinceDate:) >>> >>> >>> I have a hard time thinking of a call site where `sinceDate` would be an >>> improvement over `since`; the preposition already *strongly* implies a >>> temporal aspect to the parameter. >>> >>> If we remove `Date`, then in isolation I kind of like this change. The >>> problem arrives when you step out of isolation and think about the other >>> methods in its family. It would be strange to have >>> `myDate.timeInterval(since: otherDate)`, but `myDate.timeIntervalSinceNow() >>> `. >>> >>> One solution would be to add `now`, `referenceDate`, and `unixEpoch` (or >>> `utc1970`) as static properties on `Date`. Then you could have just the one >>> `timeInterval(since:)` method: >>> >>> myDate.timeInterval(since: otherDate) >>> myDate.timeInterval(since: .now) >>> myDate.timeInterval(since: .referenceDate) >>> myDate.timeInterval(since: .unixEpoch) >>> >>> Another solution would be to add a `-` operator that takes two `Date`s >>> and returns a `TimeInterval`, sidestepping the wording issue entirely. >>> >>> (5) myArray.each(inClosure: ) >>> >>> >>> I don't get this name at all. This operation is completely imperative >>> and side-effectful, but there's no verb? How is it "in" the closure? Why >>> "closure" when you can pass a function, and in fact you probably will >>> *only* see this label if you're passing a function? >>> >>> I do think there's a problem with `forEach(_:)`—it ought to be >>> `forEach(do:)`. This is much like `DispatchQueue.async(execute:)` or >>> the `withoutActuallyEscaping(_:do:)` function in the standard library. >>> When you pass a function parameter, and the call's primary purpose is to >>> run that parameter, it's often best to attach the verb to that parameter >>> instead of putting it in the base name. Of course, the complication there >>> is that the verb doesn't actually get written if you use trailing closure >>> syntax, but the curlies sort of fill that role. Kind of. >>> >>> Although I do understand removing "string" from the latter was to reduce >>> redundancy in function/method declarations, we only make one declaration, >>> yet we make many calls. So increasing ambiguity in calls does not seem like >>> a good trade-off for decreased boilerplate in declarations. More often than >>> not it's calls that we're reading, not the declarations—unless of course >>> the call was ambiguous and we had to read the declaration to make sense out >>> of it. So perhaps we might question if increased ambiguity is an overall >>> good thing. >>> >>> >>> I think you misunderstand the current Guidelines' goals. The Guidelines >>> are not trying to reduce redundancy at declaration sites—they're trying to >>> reduce redundancy at *call sites*. The idea is that, if the variable names >>> for the method's target and parameters imply something about the types they >>> contain, those names along with the prepositions will imply the purpose of >>> each parameter, and therefore the call. The types are just a more formal >>> version of that check. >>> >>> That's why the very first paragraph of the API Design Guidelines < >>> https://swift.org/documentation/api-design-guidelines/> says: >>> >>> Clarity at the point of use is your most important goal. Entities such >>> as methods and properties are declared only once but used repeatedly. >>> Design APIs to make those uses clear and concise. When evaluating a design, >>> reading a declaration is seldom sufficient; always examine a use case to >>> make sure it looks clear in context. >>> >>> >>> So the tradeoff is not between *declaration redundancy* and call site >>> clarity—it is between *call site redundancy* and call site ambiguity. >>> Because their parameters are unlabeled, most languages have severe call >>> site ambiguity problems. Objective-C has a pretty serious call site >>> redundancy problem. Swift's design is trying to hit the baby bear "just >>> right" point. >>> >>> It is quite possible that, in some areas, we have swung too far back >>> towards ambiguity. But I don't think `elementRemoved(atIndex:)` is going to >>> fix that. >>> >>> However this removal of explicit contextual cues from the method >>> signature harms readability, since now, the compiler will let people write >>> code like: >>> >>> { return $0.fetch(withRecordID:$1) } >>> >>> Clearly, the onus is now on the developer not to use cryptic, short >>> variable names or NO variable names. However, spend much time on GitHub or >>> in CocoaPods and you will see an increasing number of codebases where >>> that's exactly what they do, especially in closures. >>> >>> >>> What I think you're missing with this example—and in fact with all of >>> your closure-based examples—is that closures don't exist in isolation; >>> they're in some larger context. (Otherwise, they won't compile.) For >>> instance, the above closure might be in a line like: >>> >>> return zip(databases, recordIDs) >>> .map { return $0.fetch(withRecordID:$1) } >>> >>> Read in the context of its line, the meanings of $0 and $1 are fairly >>> clear. >>> >>> Another problem is that the compiler doesn't care if you write: >>> >>> { ambiguousName in >>> let myRecordID = ambiguousName.fetch(withRecordID:myID) >>> return myRecordID } >>> >>> This is highly problematic because someone reading this code will have >>> no reason to expect the type of "myRecordID" not to be CKRecordID. (In >>> fact, it's CKRecord.) >>> >>> >>> Again, in the larger context, this line will end up generating a >>> `[CKRecord]` array instead of a `[CKRecordID]` array, which is probably >>> going to cause a type mismatch once you try to actually use the alleged >>> record IDs. (But as I said earlier, I can see the case for using >>> `fetchRecord(withID:)` or `fetchRecord(with:)` instead of >>> `fetch(withRecordID:)`.) >>> >>> Ambiguous names can hide bugs in their ambiguity, but verbose names can >>> also hide bugs in the sheer mass of code they generate. The difference is, >>> developers can manage the ambiguity in their code by naming variables well, >>> but they can't manage verbosity if verbose names are imposed on them. >>> >>> We also have examples like: >>> >>> { return $0.draw(with:$1) } >>> >>> What is $0? What is $1? This is a real Apple API, BTW. >>> >>> >>> Again, the context of the closure would tell you, but part of the >>> problem here is that they held onto an Objective-C preposition which was >>> poorly chosen. If the line were `$0.draw(in:$1)`, you would know that >>> `$1` specified an area of the screen and `$0` was something that could be >>> drawn, which frankly is all you really *need* to know to understand what >>> this line does. >>> >>> {array, key in >>> let number = array.remove(at:key) >>> return number } >>> >>> This will compile and run even though number will be a tuple key-value >>> pair, array will be a dict, and key will be an index type! This may seem >>> like a ridiculous example, but I have literally seen things like this. >>> >>> >>> Where have you seen something like this? `array` would have to be passed >>> `inout` for this to work at all. >>> >>> Nevertheless, how would more verbose names help with this problem? This >>> is every bit as incorrect, and the compiler will still accept it: >>> >>> {array, key in >>> let number = array.elementRemoved(atIndex:key) >>> return number } >>> >>> Are you thinking that they'll notice that `atIndex` is not `atKey`? >>> There is already a much stronger safeguard against that: `Dictionary.Index` >>> and `Dictionary.Key` are different, totally incompatible types. Every >>> mechanism I can think of to get a `Dictionary.Index` has "index" or >>> "indices" in its name, so you could only make this mistake if you confused >>> dictionary indices with dictionary keys, in which case `atIndex:` would not >>> stand out to you either. >>> >>> Ultimately, unless the compiler actually understands identifiers, it's >>> just not going to be able to catch mistakes like calling a dictionary an >>> "array", or many of the other problems you describe here. But the type >>> system can and often does flag these kinds of problems pretty close to the >>> source. >>> >>> Orphaning method signatures by stripping useful return type and argument >>> type information wouldn't be so bad if variables were all named >>> descriptively, but that is a strangely optimistic hope for a language >>> that's as paranoid about safety that it was specifically designed to >>> prevent many categories of common mistakes. >>> >>> >>> Personally, I think of Swift's approach to safety as similar to Reagan's >>> "trust, but verify". Our naming conventions trust the programmer to write >>> code with clear names; our picky type system verifies that the code is >>> plausible. We don't force the programmer to explain herself to us until we >>> notice that something doesn't seem right. >>> >>> The bottom line is, a language can't force you to write clear and >>> correct code, but it has many tools it can use to encourage it. Swift >>> chooses not to use the "heavily redundant names" tool because its cost to >>> good code is too high. We instead rely more on other tools, like strong >>> typing, value types, and definite initialization, to encourage high-quality >>> code at a lower cost. >>> >>> >>> More verbose rather than heavily redundant names tool, but what have we >>> lost by being reliant on strongish static typing and value types? Would >>> Cocoa/ UIKit be so nice to use if rewritten fully in idiomatic non @objc >>> Swift (compared to working with UI on C++ platforms)? What would it tell us? >>> Sorry for the rant... do not take static typing laying down j/k ;). >>> (still quite in “love” with the opt-in security that annotations and clang >>> warnings bring in Objective-C rather than the opt-out freedom model some >>> other languages have) >>> >>> -- >>> Brent Royal-Gordon >>> Architechies >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> >>> >>> >> >
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