> On 21 May 2016, at 15:47, Honza Dvorsky <[email protected]> wrote:
>
> While I agree that it'd be nice to add a Map abstraction into which we could
> move a lot of the Dictionary-ness, my original pitch is *just* about adding
> the specific implementation of `mapValues` in its regular, non-lazy form. My
> example was about only keeping a subset of the information in memory in a
> Dictionary to allow for quick and frequent access (lazy goes against that). I
> think it'd be better to get that in first, or at least evaluate that
> separately from a comprehensive refactoring of the Dictionary, which would
> just accumulate more opinions and slow this specific step down.
Sorry, my point was that I think it’s better to wait until we can also do the
lazy equivalent and have both done together, otherwise we end up with one map
function that can work both lazily and one that never does. Sure that will
require a refactoring into a protocol, but it seems to me that it’s better to
do that as the first step, then add the feature after that. In the mean time
extensions have you well covered for convenience.
Another alternative to this feature might be to add a key/value pair
constructor to Dictionary (it technically already has one, but it’s variadic
only) so you could do something like this:
let myTransformedDictionary = Dictionary(myIntegerDictionary.lazy.map {
($0, $1 + 5) })
Since this would be a useful initialiser both now and in future. I dunno, it’s
just my opinion, but I find it a bit weird to get half the implementation now,
and could lead to misunderstandings with people trying to do
myMap.lazy.mapValues (won’t be recognised) and wondering why there isn’t one._______________________________________________
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