Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

@Nate: Just another pitch. Do we really want the DocumentValues to be a MutableCollection? There are default implementations like sort which would destroy the correctness of your unordered dictionary. IMO all mutating functionality should be added manually to DocumentValues to ensure that it d

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 15, 2016, at 8:34 PM, Dave Abrahams via swift-evolution > wrote: > > > on Fri Oct 14 2016, Paul Cantrell > wrote: > >> A late-arriving strong +1 for me. The index-related stuff is elegant and >> much needed. I’m surprised >> to learn that dict.keys

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

on Fri Oct 14 2016, Paul Cantrell wrote: > A late-arriving strong +1 for me. The index-related stuff is elegant and much > needed. I’m surprised > to learn that dict.keys and dict.values are copies and not already > views! They are views. > Clearly they should be. > > Question: I hit a close

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

A late-arriving strong +1 for me. The index-related stuff is elegant and much needed. I’m surprised to learn that dict.keys and dict.values are copies and not already views! Clearly they should be. Question: I hit a closely related performance wall just last week, doing something like this:

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 13, 2016, at 1:28 AM, Dave Abrahams via swift-evolution > wrote: > > on Wed Oct 12 2016, Nate Cook > wrote: > >>> On Oct 12, 2016, at 9:32 AM, plx via swift-evolution >>> wrote: >>> >>> The issue addressed is real; I’m not sure this is the best app

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

on Wed Oct 12 2016, Nate Cook wrote: >> On Oct 12, 2016, at 9:32 AM, plx via swift-evolution >> wrote: >> >> The issue addressed is real; I’m not sure this is the best approach. >> >> In particular, unless I’m missing something obvious, the ownership strategy >> here would have to be: >>

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

on Wed Oct 12 2016, Alexis wrote: > Just to clarify: It seems like the only ABI-affecting change here is the type > of keys/values. As you > note at the end of your proposal, this should just be > Dictionary.Keys/Dictionary.Values regardless > of whether we implement this proposal or not, in w

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

on Tue Oct 11 2016, Nate Cook wrote: > Introduction > > This proposal addresses significant unexpected performance gaps when using > dictionaries. It > introduces type-specific collections for a Dictionary instance's keys and > values properties. > > New DictionaryKeys and DictionaryValues col

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 11, 2016, at 2:28 PM, Nate Cook via swift-evolution > wrote: > > Inefficient > Value Mutation > > Dictionary values can be modified through the keyed subscript by direct > reassignment

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

I agree that at least for stdlib purposes there’s something that looks like an explicit choice to make in-place mutation *available*. What I was trying to explain is whether or not in-place mutation *happens* is a bit implicit. It’s one thing to say that the difference here is just an idiom to

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

I believe the implementation of efficient in-place mutation is very explicit in the code -- it is done by implementing DictionaryValue’s subscript using a special “mutableAddressWithNativeOwner” addressor instead of a normal setter. https://github.com/natecook1000/swift/blob/ed95aec4a20589a3b9c

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Just to clarify: It seems like the only ABI-affecting change here is the type of keys/values. As you note at the end of your proposal, this should just be Dictionary.Keys/Dictionary.Values regardless of whether we implement this proposal or not, in which case this can be punted for Swift 4. It s

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Thanks for the quick reply; given that I’m quite wrong about the important mechanics I rescind my criticisms. I will say I care about this enough to reply because the inability to do in-place mutation of dictionary values has been an incredibly frustrating limitation and I’d just assumed the si

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 12, 2016, at 10:58 AM, Károly Lőrentey via swift-evolution > wrote: > > I think this is a lovely approach to solving this API design problem. > > One thing I don’t quite understand yet is how these kinds of mutable views > interact with copy on write semantics. COW rules can be subtl

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Ah, I see plx has already brought this up. So this is a bug in the implementation, and (presumably) DictionaryValue’s mutable subscript addressor is supposed to take care of COW semantics without introducing needless copying. (It’s too bad we aren’t supposed to use these magical addressors outsi

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

I think this is a lovely approach to solving this API design problem. One thing I don’t quite understand yet is how these kinds of mutable views interact with copy on write semantics. COW rules can be subtle, and these views seem to put an extra twist on top that seems hard to understand/explain

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

On Wed, Oct 12, 2016 at 10:31 AM, Nate Cook via swift-evolution < swift-evolution@swift.org> wrote: > Thanks for your feedback! Response below. > > On Oct 12, 2016, at 5:40 AM, Daniel Vollmer via swift-evolution < > swift-evolution@swift.org> wrote: > > Hi, > > I very much think the points mention

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Thanks for your feedback! Response below. > On Oct 12, 2016, at 5:40 AM, Daniel Vollmer via swift-evolution > wrote: > > Hi, > > I very much think the points mentioned in the motivation are worth addressing > (and IMO this is not an area where “maybe the optimizer can be made smarter” > can

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 12, 2016, at 9:32 AM, plx via swift-evolution > wrote: > > The issue addressed is real; I’m not sure this is the best approach. > > In particular, unless I’m missing something obvious, the ownership strategy > here would have to be: > > - `DictionaryKeys` and `DictionaryValues` wou

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

The issue addressed is real; I’m not sure this is the best approach. In particular, unless I’m missing something obvious, the ownership strategy here would have to be: - `DictionaryKeys` and `DictionaryValues` would each induce the expected +1 retain on the underlying storage - `DictionaryValu

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

+1 from me. Seems like a solid change. On Wed, Oct 12, 2016 at 12:39 AM, Jacob Bandes-Storch via swift-evolution < swift-evolution@swift.org> wrote: > +1. Haven't hit this issue personally, but I agree it's important and the > proposed solution seems like the right fix. > > On Tue, Oct 11, 2016 a

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

A clear win for me. +1 > On 11 Oct 2016, at 23:28, Nate Cook via swift-evolution > wrote: > > Introduction > > This proposal addresses significant unexpected performance gaps when using > dictionaries. It introduces type-specific collections for a Dictionary > instance's keys and values pro

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Hi, I very much think the points mentioned in the motivation are worth addressing (and IMO this is not an area where “maybe the optimizer can be made smarter” can cut it; I want performance guarantees, not hopes). > On 11 Oct 2016, at 23:28, Nate Cook via swift-evolution > wrote: [snip] On

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

+1 On Wed, 12 Oct 2016 at 09:09 Said Sikira via swift-evolution < swift-evolution@swift.org> wrote: > +1 > > > On October 12, 2016 at 8:54:45 AM, Rien via swift-evolution ( > swift-evolution@swift.org) wrote: > > Beautiful, +1 > > Rien > > > On 11 Oct 2016, at 23:28, Nate Cook via swift-evolution

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

+1 On October 12, 2016 at 8:54:45 AM, Rien via swift-evolution ( swift-evolution@swift.org) wrote: Beautiful, +1 Rien > On 11 Oct 2016, at 23:28, Nate Cook via swift-evolution < swift-evolution@swift.org> wrote: > > Introduction > > This proposal addresses significant unexpected performance ga

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Beautiful, +1 Rien > On 11 Oct 2016, at 23:28, Nate Cook via swift-evolution > wrote: > > Introduction > > This proposal addresses significant unexpected performance gaps when using > dictionaries. It introduces type-specific collections for a Dictionary > instance's keys and values propert

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

+1. Haven't hit this issue personally, but I agree it's important and the proposed solution seems like the right fix. On Tue, Oct 11, 2016 at 2:28 PM, Nate Cook via swift-evolution < swift-evolution@swift.org> wrote: > Introduction > > This proposal addresses significant unexpected performance ga

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

> On Oct 11, 2016, at 5:06 PM, Braeden Profile wrote: > > Awesome; +1. Does this address the lack of .init(keys:values:)? Would it > make that addition easier? No, I don't think this has any bearing on that question. There's a separate proposal for that sort of initializer that was deferred

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

I agree. I like this proposal. -- E > On Oct 11, 2016, at 3:38 PM, Xiaodi Wu via swift-evolution > wrote: > > Very elegant solution. Strong +1; no other feedback comes to mind atm. > > > On Tue, Oct 11, 2016 at 4:28 PM, Nate Cook via swift-evolution > mailto:swift-evolution@swift.org>> wrot

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Awesome; +1. Does this address the lack of .init(keys:values:)? Would it make that addition easier? > On Oct 11, 2016, at 3:38 PM, Xiaodi Wu via swift-evolution > wrote: > > Very elegant solution. Strong +1; no other feedback comes to mind atm. > > > On Tue, Oct 11, 2016 at 4:28 PM, Nate C

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

As someone who's hit this performance issue myself, a big +1 from me. The solution looks like it fits perfectly into Swift. On Tue, Oct 11, 2016 at 3:01 PM Matthew Johnson via swift-evolution < swift-evolution@swift.org> wrote: > Looks very nice. +1 here as well. > > On Oct 11, 2016, at 4:28 PM

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Looks very nice. +1 here as well. > On Oct 11, 2016, at 4:28 PM, Nate Cook via swift-evolution > wrote: > > Introduction > > This proposal addresses significant unexpected performance gaps when using > dictionaries. It introduces type-specific collections for a Dictionary > instance's keys

Re: [swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Very elegant solution. Strong +1; no other feedback comes to mind atm. On Tue, Oct 11, 2016 at 4:28 PM, Nate Cook via swift-evolution < swift-evolution@swift.org> wrote: > Introduction > > This proposal addresses significant unexpected performance gaps when using > dictionaries. It introduces ty

[swift-evolution] [Proposal Draft] Provide Custom Collections for Dictionary Keys and Values

Introduction This proposal addresses significant unexpected performance gaps when using dictionaries. It introduces type-specific collections for a Dictionary instance's keys and values properties. New DictionaryKeys and DictionaryValues collections provide efficient key lookup and mutable acc