Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

On Fri, Dec 9, 2016, at 11:50 AM, Dave Abrahams via swift-evolution wrote: > > on Fri Dec 09 2016, Andrew Trick wrote: > > >> On Dec 9, 2016, at 10:27 AM, Dave Abrahams via swift-evolution > > wrote: > >> > >> > >> on Thu Dec 08 2016, Xiaodi Wu >> > wrote: > >

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 9, 2016, at 11:50 AM, Dave Abrahams via swift-evolution > wrote: > > > on Fri Dec 09 2016, Andrew Trick wrote: > >>> On Dec 9, 2016, at 10:27 AM, Dave Abrahams via swift-evolution >> wrote: >>> >>> >>> on Thu Dec 08 2016, Xiaodi Wu >> > wrote: >>>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Fri Dec 09 2016, Andrew Trick wrote: >> On Dec 9, 2016, at 10:27 AM, Dave Abrahams via swift-evolution > wrote: >> >> >> on Thu Dec 08 2016, Xiaodi Wu > > wrote: >> > >>> On Thu, Dec 8, 2016 at 6:53 PM, Ben Cohen via swift-evolution < >>> swift-evolution@sw

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Ben Cohen wrote: > Probably needs an argument label since it's performing an explicit purpose, > not just a vanilla > conversion initializer. So maybe > UnsafeRawBufferPointer.init(rebasing:) I disagree that we need a label here. It's a value-preserving conversion; the res

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 9, 2016, at 10:27 AM, Dave Abrahams via swift-evolution > wrote: > > > on Thu Dec 08 2016, Xiaodi Wu > wrote: > >> On Thu, Dec 8, 2016 at 6:53 PM, Ben Cohen via swift-evolution < >> swift-evolution@swift.org> wrote: >> >>> >>> On Dec 8, 2016, at 4:3

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 9, 2016, at 10:22 AM, Dave Abrahams wrote: > > > on Thu Dec 08 2016, Jordan Rose wrote: > >>> On Dec 8, 2016, at 16:22, Andrew Trick via swift-evolution >>> wrote: >>> In practice, it needs to be able to interoperate with [UInt8] and be >>> interchangeable in the same >> generic c

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Xiaodi Wu wrote: On Thu, Dec 8, 2016 at 6:53 PM, Ben Cohen via swift-evolution < swift-evolution@swift.org> wrote: On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution < swift-evolution@swift.org> wrote: Um, Sequence doesn’t have a subscript (or indexes). Sequenc

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Ben Cohen wrote: On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution wrote: Um, Sequence doesn’t have a subscript (or indexes). Sequences are single-pass. So if this is important, it needs to stay a Collection. Just because something fulfills one of the req

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Jordan Rose wrote: On Dec 8, 2016, at 16:22, Andrew Trick via swift-evolution wrote: In practice, it needs to be able to interoperate with [UInt8] and be interchangeable in the same generic context. e.g. `byteBuffer += rawBuffer[payloadIndex..typical. I think Seque

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

Probably needs an argument label since it's performing an explicit purpose, not just a vanilla conversion initializer. So maybe UnsafeRawBufferPointer.init(rebasing:) Or since we have same-type constrained extensions now on master maybe you could do it as a property: extension RandomAccessSli

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

So now that I look at it, it appears UnsafeRawBufferPointer(copyBytes:) has the same problems we are trying to solve on initialize(as:from) i.e. it is completely at the mercy of the passed-in collection's count being accurate, and if it isn't it'll scribble over memory. We should probably apply

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 5:44 PM, Xiaodi Wu via swift-evolution > wrote: > > On Thu, Dec 8, 2016 at 6:53 PM, Ben Cohen via swift-evolution > mailto:swift-evolution@swift.org>> wrote: > >> On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution >> mailto:swift-evolution@swift.org>> wrote: >>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

On Thu, Dec 8, 2016 at 6:53 PM, Ben Cohen via swift-evolution < swift-evolution@swift.org> wrote: > > On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution < > swift-evolution@swift.org> wrote: > > Um, Sequence doesn’t have a subscript (or indexes). Sequences are > single-pass. So if this is

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

Sorry, let me clarify. Can you, Dave, elaborate as to why the issue you stated as "this" ("untyped memory without bounds checks" conforming to Collection) seems, as you say, "suspect"? On Thu, Dec 8, 2016 at 18:32 Dave Abrahams wrote: on Thu Dec 08 2016, Xiaodi Wu wrote: > Can you elaborate o

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 4:54 PM, Jordan Rose wrote: > > >> On Dec 8, 2016, at 16:53, Ben Cohen > > wrote: >> >> >>> On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution >>> mailto:swift-evolution@swift.org>> wrote: >>> >>> Um, Sequence doesn’t have a subscrip

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 16:53, Ben Cohen wrote: > > >> On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution >> mailto:swift-evolution@swift.org>> wrote: >> >> Um, Sequence doesn’t have a subscript (or indexes). Sequences are >> single-pass. So if this is important, it needs to stay a Col

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 4:35 PM, Jordan Rose via swift-evolution > wrote: > > Um, Sequence doesn’t have a subscript (or indexes). Sequences are > single-pass. So if this is important, it needs to stay a Collection. > Just because something fulfills one of the requirements of a Collection does

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 16:22, Andrew Trick via swift-evolution > wrote: > > In practice, it needs to be able to interoperate with [UInt8] and be > interchangeable in the same generic context. > > e.g. `byteBuffer += rawBuffer[payloadIndex.. > I think Sequence is sufficient for that purpose. U

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Xiaodi Wu wrote: Can you elaborate on this? Why aren't you sure this is a wise idea? Whom are you asking? What is “this?” -- -Dave ___ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/list

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 12:50 PM, Dave Abrahams via swift-evolution > wrote: > > > on Thu Dec 08 2016, Ben Cohen wrote: > >>> On Dec 2, 2016, at 8:27 PM, Nate Cook wrote: >>> On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution mailto:swift-evolution@swift.org>> wrote: >>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

Can you elaborate on this? Why aren't you sure this is a wise idea? On Thu, Dec 8, 2016 at 16:19 Dave Abrahams via swift-evolution < swift-evolution@swift.org> wrote: > > on Thu Dec 08 2016, Alexis Beingessner wrote: > > >> On Dec 8, 2016, at 3:50 PM, Dave Abrahams via swift-evolution < > swift-

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Alexis Beingessner wrote: >> On Dec 8, 2016, at 3:50 PM, Dave Abrahams via swift-evolution >> wrote: >> >> >> on Thu Dec 08 2016, Ben Cohen wrote: >> > On Dec 2, 2016, at 8:27 PM, Nate Cook wrote: > On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evoluti

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 8, 2016, at 3:50 PM, Dave Abrahams via swift-evolution > wrote: > > > on Thu Dec 08 2016, Ben Cohen wrote: > >>> On Dec 2, 2016, at 8:27 PM, Nate Cook wrote: >>> On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution mailto:swift-evolution@swift.org>> wrote: >>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 08 2016, Ben Cohen wrote: >> On Dec 2, 2016, at 8:27 PM, Nate Cook wrote: >> >>> On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution >>> mailto:swift-evolution@swift.org>> >>> wrote: > >>> On Dec 1, 2016, at 11:33 PM, Nate Cook via swift-evolution mailto:swift-evolu

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 2, 2016, at 8:27 PM, Nate Cook wrote: > >> On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution >> mailto:swift-evolution@swift.org>> wrote: >> >>> On Dec 1, 2016, at 11:33 PM, Nate Cook via swift-evolution >>> mailto:swift-evolution@swift.org>> wrote: >>> >>> 3) Make all buffe

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution > mailto:swift-evolution@swift.org>> wrote: > >> On Dec 1, 2016, at 11:33 PM, Nate Cook via swift-evolution >> mailto:swift-evolution@swift.org>> wrote: >> >> 3) Make all buffer pointers their own slices but use a different index type.

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

How about providing an Int subscript in addition to switching the index type for the purpose of Subsequence? > On Dec 2, 2016, at 2:12 PM, Ben Cohen via swift-evolution > wrote: > > >> On Dec 1, 2016, at 11:33 PM, Nate Cook via swift-evolution >> mailto:swift-evolution@swift.org>> wrote: >>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Dec 1, 2016, at 11:33 PM, Nate Cook via swift-evolution > wrote: > > 3) Make all buffer pointers their own slices but use a different index type. > If the indices were just wrapped pointers, that would handle the index > sharing without needing an additional property on the buffer. We co

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

+1 on the third option it being clearly the best way to model pointers. Making the index strideable makes its use in index computations easy. It takes a bit care to make it work as conveniently for UnsafeBufferPointer where the stride will need to be special. > On Dec 1, 2016, at 11:33 PM, Nat

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Nov 30, 2016, at 6:15 PM, Dave Abrahams via swift-evolution > wrote: > > on Wed Nov 30 2016, Kevin Ballard > wrote: > >> This sounds like a sensible idea. But there is one behavioral change you >> haven't addressed, which is that this changes how indexes

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Thu Dec 01 2016, Jordan Rose wrote: >> On Nov 30, 2016, at 16:15, Dave Abrahams via swift-evolution > wrote: >> >> >> on Wed Nov 30 2016, Kevin Ballard >> >> > >> wrote: >> >>> This sounds like a sensible idea. But there is one behavioral change you >>>

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

> On Nov 30, 2016, at 16:15, Dave Abrahams via swift-evolution > wrote: > > > on Wed Nov 30 2016, Kevin Ballard > wrote: > >> This sounds like a sensible idea. But there is one behavioral change you >> haven't addressed, which is that this changes how indexe

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

on Wed Nov 30 2016, Kevin Ballard wrote: > This sounds like a sensible idea. But there is one behavioral change you > haven't addressed, which is that this changes how indexes work on the > slice. With all other slice types that come to mind, the slice shares > the same indexes as the base, e.g.

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

This sounds like a sensible idea. But there is one behavioral change you haven't addressed, which is that this changes how indexes work on the slice. With all other slice types that come to mind, the slice shares the same indexes as the base, e.g. let ary = Array(0..<10) print(ary[3]) // pri

Re: [swift-evolution] [Pitch] Normalize Slice Types for Unsafe Buffers

+1. Sensible change. > On 30 Nov 2016, at 18:15, Nate Cook via swift-evolution > wrote: > > Hello all— > > This is a proposal for a fairly minor change in slicing behavior for unsafe > buffers. > > Nate > > > -- > > > This proposal changes Swift's typed UnsafeBufferPointers to be the