Just to add to that, it’s always seemed strange to me that to signify your sequence is multi-pass (i.e., to make it conform to CollectionType) you have to have it conform to Indexable.
> On 31 Dec 2015, at 17:52, Erica Sadun via swift-evolution > <[email protected]> wrote: > > I'm trying to work them out, so it's still muddled. > > Right now, I think SequenceType is better described as CollectionWalkType but > that's kind of (1) a mouthful and (2) not entirely accurate. > > Moving back a step: SequenceType is defined as: "A type that can be iterated > with a `for`...`in` loop." But it says nothing about whether that loop ever > terminates and many stdlib sequence functions currently don't make sense (at > least if they're not lazy) with respect to infinite sequences, which should > probably be "StreamType" not sequences. A couple of examples: > Here's my fib: http://swiftstub.com/189513594/ > <http://swiftstub.com/189513594/> > And here's Oisin's user-input sequence: > https://gist.github.com/oisdk/2c7ac33bf2188528842a > <https://gist.github.com/oisdk/2c7ac33bf2188528842a> > Both of these are theoretically filterable, but they aren't dropLast-able, > suffix-able, properly split-able, etc. > > Hopefully that's enough of a starting point to indicate where my thinking is > at and what I'm trying to think through when it comes to this. -- E > > >> On Dec 31, 2015, at 10:09 AM, Dave Abrahams <[email protected] >> <mailto:[email protected]>> wrote: >> >> >>> On Dec 31, 2015, at 9:05 AM, Erica Sadun via swift-evolution >>> <[email protected] <mailto:[email protected]>> wrote: >>> >>> It does seem that in Swift the concepts of collection, sequence, >>> permutation, stream, etc are a bit muddled. >> >> This is a pretty vague critique. Do you have specifics, and suggestions >> that address them? >> >>> >>> -- E >>> >>> >>>> On Dec 31, 2015, at 6:51 AM, Tino Heth via swift-evolution >>>> <[email protected] <mailto:[email protected]>> wrote: >>>> >>>>> Those are collections. Collections can be iterated over multiple times. >>>> Speaking of the Fibonacci-numbers: >>>> Sure we can write an algorithm that iterates over them several times — it >>>> just won't ever finish the first iteration ;-) >>>> (only nitpicking — I just couldn't resist) >>>> >>>> Happy new year! >>>> _______________________________________________ >>>> swift-evolution mailing list >>>> [email protected] <mailto:[email protected]> >>>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> [email protected] <mailto:[email protected]> >>> https://lists.swift.org/mailman/listinfo/swift-evolution >> >> -Dave >> > > _______________________________________________ > swift-evolution mailing list > [email protected] <mailto:[email protected]> > https://lists.swift.org/mailman/listinfo/swift-evolution > <https://lists.swift.org/mailman/listinfo/swift-evolution>
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