Thanks Erica. I’ve been able to transform arrays of strings into arrays of my
OptionSets using an enum approach like you describe. I was looking more for a
generic approach that I could apply to all of the various OptionSets I have to
decode from JSON. I suppose whether it’s from an array of strings or array of
the OptionSet is less important, but getting to the array of the OptionSet
itself is something I can already do.
Thanks,
Jon
> On Nov 3, 2016, at 9:37 PM, Erica Sadun <er...@ericasadun.com> wrote:
>
> Maybe something like this? Or you could just bitwise || individual sets. Or
> you could use a dictionary to lookup [string: rawValue]. etc.
>
> public struct MyOptionSet: OptionSet {
> public static let one = MyOptionSet(rawValue: 1 << 0)
> public static let two = MyOptionSet(rawValue: 1 << 1)
> public static let three = MyOptionSet(rawValue: 1 << 2)
>
> public var rawValue: Int { return _rawValue }
> public init(rawValue: Int) { self._rawValue = rawValue }
> private let _rawValue: Int
>
> private enum StringEnum: String { case one, two, three }
> public init(strings: [String]) {
> var set = MyOptionSet()
> strings.flatMap({ StringEnum(rawValue: $0) })
> .flatMap({ MyOptionSet(rawValue: 1 << $0.hashValue) })
> .forEach { set.insert($0) }
> _rawValue = set.rawValue
> }
> }
>
> let stringArray: [String] = ["one", "three"]
> let stringOptions = MyOptionSet(strings: stringArray)
> stringOptions.rawValue
>
>> On Nov 3, 2016, at 7:09 PM, Jon Shier via swift-users <swift-users@swift.org
>> <mailto:swift-users@swift.org>> wrote:
>>
>> Swifters:
>> I’m dealing with a JSON API where sets of options are returned as
>> arrays of strings. Representing these as OptionSets seems ideal. I can
>> decode the arrays of strings into an array of individual OptionSet values,
>> but I’ve run into a dead end when trying generically reduce the array of
>> OptionSets to a single OptionSet value. I’ve tried variety of ways of
>> definition a Collection extension, even tried defining a global function,
>> but I can’t seem to use the OptionSet sequence initializer or reduce itself
>> (cannot invoke insert with argument of type (OptionSet) (or T)). Any
>> guidance here?
>> Here’s what I’ve tried:
>>
>> extension Collection where Iterator.Element == OptionSet {
>>
>> func reduced() -> Iterator.Element {
>> return reduce(Iterator.Element()) {
>> var newResult = $0
>> newResult.insert($1)
>> return newResult
>> }
>> }
>>
>> }
>>
>> extension Collection where Iterator.Element == OptionSet {
>>
>> func reduced<T: OptionSet>() -> T {
>> return reduce(T()) {
>> var newResult = $0
>> newResult.insert($1)
>> return newResult
>> }
>> }
>>
>> }
>>
>>
>> extension Collection where Iterator.Element == OptionSet {
>> func reduced() -> Iterator.Element {
>> return Iterator.Element(self)
>> }
>> }
>>
>> func reduced<T: OptionSet>(_ options: [T]) -> T {
>> return options.reduce(T()) {
>> var newResult = $0
>> newResult.insert($1)
>>
>> return newResult
>> }
>> }
>>
>> Jon Shier
>> _______________________________________________
>> swift-users mailing list
>> swift-users@swift.org <mailto:swift-users@swift.org>
>> https://lists.swift.org/mailman/listinfo/swift-users
>
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