[swift-evolution] map-like operation that returns a dictionary

[Donnacha Oisín Kidney]

I think that use of map is generally discouraged. forEach would probably be more explicit, or a for-loop.

> On 10 Jan 2016, at 18:58, 肇鑫 via swift-evolution <swift-evolution at swift.org> wrote:
> 
> You can use dictionary in a map. You just ignore the return value of the map.
> 
> var dic = [Int:String]()
> var index = 0
> 
> ["John", "Mike", "Amy", "Kavin"].map {
>     dic.updateValue($0, forKey: index)
>     index += 1
> }
> 
> print(dic) // [2: "Amy", 0: "John", 1: "Mike", 3: "Kavin"]
> 
> zhaoxin
> 
> On Mon, Jan 11, 2016 at 1:50 AM, Kenny Leung via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
> Hi All.
> 
> I find that instead of using map() on arrays, I more often use an operation that returns a dictionary from an array. A common case is fetching an array of data, then creating a local cache of it indexed by ID.
> 
> Is there a name for this operation? Is this something that others would like to see added to the standard library?
> 
> -Kenny
> 
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org <mailto:swift-evolution at swift.org>
> https://lists.swift.org/mailman/listinfo/swift-evolution <https://lists.swift.org/mailman/listinfo/swift-evolution>
> 
> 
> 
> -- 
> 
> Owen Zhao
>  _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160110/d30fdff7/attachment.html>