[swift-evolution] sortBy, minElementBy and maxElementBy methods

[Susan Cheng]

yes.
Shouldn't have shorter names to replace the minElementBy, maxElementBy and
sortInPlaceBy

minBy and maxBy?

Jacob Bandes-Storch <jtbandes at gmail.com> 於 2015年12月31日星期四 寫道：

> +1, although I wonder if the method names should be distinct (such as
> minElementBy, sortBy, etc.)
>
> On Wed, Dec 30, 2015 at 10:38 PM, Susan Cheng via swift-evolution <
> swift-evolution at swift.org
> <javascript:_e(%7B%7D,'cvml','swift-evolution at swift.org');>> wrote:
>
>>
>> Consider the follows:
>>
>>
>> struct Person {
>>
>>
>>
>>     var name: String
>>
>>     var age: Int
>>
>> }
>>
>>
>> let peoples = [Person(name: "Hawk", age: 24), Person(name: "Andrew",
>> age: 23)]
>>
>>
>> let youngest = peoples.minElement { $0.age < $1.age }
>>
>>
>> print(youngest?.name)
>>
>>
>> it's silly that we always have to write the code like { $0.some < $1.some }
>> or { some($0) < some($1) }
>>
>>
>> so, we should add those methods to stdlib:
>>
>>
>> extension SequenceType {
>>
>>     /// Returns the minimum element in `self` or `nil` if the sequence
>> is empty.
>>
>>     ///
>>
>>     /// - Complexity: O(`elements.count`).
>>
>>     ///
>>
>>     @warn_unused_result
>>
>>     public func minElement<R : Comparable>(@noescape by:
>> (Generator.Element) throws -> R) rethrows -> Generator.Element? {
>>
>>         return try self.minElement { try by($0) < by($1) }
>>
>>     }
>>
>>     /// Returns the maximum element in `self` or `nil` if the sequence
>> is empty.
>>
>>     ///
>>
>>     /// - Complexity: O(`elements.count`).
>>
>>     ///
>>
>>     @warn_unused_result
>>
>>     public func maxElement<R : Comparable>(@noescape by:
>> (Generator.Element) throws -> R) rethrows -> Generator.Element? {
>>
>>         return try self.maxElement { try by($0) < by($1) }
>>
>>     }
>>
>> }
>>
>>
>> public extension MutableCollectionType {
>>
>>
>>
>>     /// Return an `Array` containing the sorted elements of `source`.
>>
>>     /// according to `by`.
>>
>>     ///
>>
>>     /// The sorting algorithm is not stable (can change the relative
>> order of
>>
>>     /// elements that compare equal).
>>
>>     @warn_unused_result(mutable_variant="sortInPlace")
>>
>>     func sort<R : Comparable>(@noescape by: (Generator.Element) -> R) ->
>> [Generator.Element] {
>>
>>         return self.sort { by($0) < by($1) }
>>
>>     }
>>
>> }
>>
>>
>> public extension MutableCollectionType where Self.Index :
>> RandomAccessIndexType {
>>
>>
>>
>>     /// Sort `self` in-place according to `by`.
>>
>>     ///
>>
>>     /// The sorting algorithm is not stable (can change the relative
>> order of
>>
>>     /// elements that compare equal).
>>
>>     mutating func sortInPlace<R : Comparable>(@noescape by: (Generator.
>> Element) -> R) {
>>
>>         self.sortInPlace { by($0) < by($1) }
>>
>>     }
>>
>> }
>>
>>
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>>
>>
>
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