[swift-evolution] Stdlib closure argument labels and parameter names
Erica Sadun
erica at ericasadun.com
Wed Jun 22 21:02:23 CDT 2016
On Jun 20, 2016, at 3:25 PM, Dave Abrahams via swift-evolution <swift-evolution at swift.org> wrote:
>
>
> Hi All,
>
> A couple of weeks ago we started to notice that we had some poorly-named
> closure parameters and argument labels in the standard library, so we
> did a complete audit of the standard library's APIs and came up with a
> preliminary proposal for changes, which we applied in a branch and you
> can review in https://github.com/apple/swift/pull/2981. Let's please
> carry on further discussion here rather than in the pull request, though.
- /// - `isEquivalent(a, a)` is always `true`. (Reflexivity)
- /// - `isEquivalent(a, b)` implies `isEquivalent(b, a)`. (Symmetry)
- /// - If `isEquivalent(a, b)` and `isEquivalent(b, c)` are both `true`, then
- /// `isEquivalent(a, c)` is also `true`. (Transitivity)
+ /// - `areEquivalent(a, a)` is always `true`. (Reflexivity)
+ /// - `areEquivalent(a, b)` implies `areEquivalent(b, a)`. (Symmetry)
+ /// - If `areEquivalent(a, b)` and `areEquivalent(b, c)` are both `true`, then
+ /// `areEquivalent(a, c)` is also `true`. (Transitivity)
I like this change!
- func forEach<S: SequenceType>(_ body: (S.Iterator.Element) -> ())
+ func forEach<S: SequenceType>(invoke body: (S.Iterator.Element) -> ())
Adding an external label makes sense here. This is a procedural call and
using it within the parens should have a "code ripple".
That said, would prefer `do` or `perform` over `invoke` or `invoking` as in
`runRaceTest`, `_forAllPermutationsImpl`, `expectFailure`, etc. This also applies
where there's a `body` label instead of an empty external label.
-public func withInvalidOrderings(_ body: ((Int, Int) -> Bool) -> Void) {
+public func withInvalidOrderings(invoke body: ((Int, Int) -> Bool) -> Void) {
For any with/external label pair, I'd prefer `with-do` or `with-perform`
over `with-invoke`.
- return IteratorSequence(it).reduce(initial, combine: f)
+ return IteratorSequence(it).reduce(initial, accumulatingBy: f)
For `reduce`, I'd prefer `applying:` or `byApplying:`
Similarly in `starts(with:comparingBy:)`, I'd prefer byComparing`,
min/max, byOrdering
- ).encode(encoding, output: output)
+ ).encode(encoding, sendingOutputTo: processCodeUnit)
How about `exportingTo`?
- tempwords.sort(isOrderedBefore: <)
+ tempwords.sort(orderingBy: <)
With `sort` and `sorted`, I'd prefer `by:`
- if !expected.elementsEqual(actual, isEquivalent: sameValue) {
+ if !expected.elementsEqual(actual, comparingBy: sameValue) {
I'm torn on this one. I don't like but I don't have a good solution.
- /// for which `predicate(x) == true`.
+ /// for which `isIncluded(x) == true`.
- _base: base.makeIterator(), whereElementsSatisfy: _include)
+ _base: base.makeIterator(), suchThat: _include)
How about simply `include` for both? I get the `is` desire but it's being tossed away
in a lot of other places in this diff. and `suchThat` feels out of place.
- || u16.contains({ $0 > 127 || _isspace_clocale($0) }) {
+ || u16.contains(elementWhere: { $0 > 127 || _isspace_clocale($0) }) {
I assume the challenge here is differentiating contains(element) from contains(closure).
This feels predicate-y, which is why I put it near the predicates. But I think something
like `containsElement(where:)` works better.
- let result = try base._withUnsafeMutableBufferPointerIfSupported(body)
+ let result = try base._withUnsafeMutableBufferPointerIfSupported(invoke: body)
I hate "ifSupported" but that's another discussion (withSupportedUnsafeMutableBufferPointer,
withAvailableUnsafeMutableBufferPointer, it's all lipstick)
This is procedural, so `do` or `perform` rather than `invoke`
- for test in removeFirstTests.filter({ $0.numberToRemove == 1 }) {
+ for test in removeFirstTests.filter(
+ suchThat: { $0.numberToRemove == 1 }
The difference between `filter` and `forEach` is that `forEach` is explicitly
procedural while `filter` is functional. I do not like functional chainable
calls being modified to use explicit external labels in this way.
I'd prefer no label here.
public func split(
maxSplits: Int = Int.max,
omittingEmptySubsequences: Bool = true,
- isSeparator: @noescape (Base.Iterator.Element) throws -> Bool
+ separatedWhere isSeparator: @noescape (Base.Iterator.Element) throws -> Bool
I'm torn on this one. It's not the worst ever but something more like where/at/when
makes more sense to me than "separatedWhere/separatedAt/separatedWhen".
+ count: __manager._headerPointer.pointee.count)
For the sake of Zippy the Pinhead, surely there has to be something better than `pointee`.
Like...`reference`?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160622/ce404f44/attachment.html>
More information about the swift-evolution
mailing list