Bah, of course. No point in trying to qualify the word; let's just call it the memory layout stride and be done with it.
On Fri, Jul 1, 2016 at 02:05 Dave Abrahams <dabrah...@apple.com> wrote: > No, actually both can be something other than the minimum. These are > usually going to be the minimum-without-performance-degradation. > > > Sent from my illudium Q-36 explosive space modulator > > On Jun 30, 2016, at 11:29 PM, Xiaodi Wu <xiaodi...@gmail.com> wrote: > > I don't think it needs qualifying. It cannot be anything other than the > minimum, just like we have `alignment` instead of `minimumAlignment`. > On Fri, Jul 1, 2016 at 00:50 Jacob Bandes-Storch via swift-evolution < > swift-evolution@swift.org> wrote: > >> There seems to be agreement that "stride" is sensical term for the >> distance between values in memory, but it seems like what MemoryLayout >> wants to expose is the *minimum* possible stride for a particular type. How >> do folks feel about "*minimumStride*"? >> >> On Thu, Jun 30, 2016 at 10:46 PM, James Berry via swift-evolution < >> swift-evolution@swift.org> wrote: >> >>> >>> > On Jun 30, 2016, at 10:07 PM, Dave Abrahams <dabrah...@apple.com> >>> wrote: >>> > >>> > >>> > on Thu Jun 30 2016, Matthew Johnson <matthew-AT-anandabits.com >>> <http://matthew-at-anandabits.com>> wrote: >>> > >>> >>> On Jun 30, 2016, at 8:12 PM, Dave Abrahams <dabrah...@apple.com> >>> wrote: >>> >>> >>> >>> >>> >>> on Thu Jun 30 2016, Matthew Johnson <matthew-AT-anandabits.com >>> <http://matthew-at-anandabits.com> <http://matthew-at-anandabits.com/>> >>> wrote: >>> >>> >>> >> >>> >>>> Sent from my iPad >>> >>>> >>> >>>>> On Jun 30, 2016, at 6:59 PM, Erica Sadun via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>>>> >>> >>>>> >>> >>>>>>> On Jun 30, 2016, at 5:47 PM, James Berry <jbe...@rogueorbit.com> >>> wrote: >>> >>>>>>> >>> >>>>>>> >>> >>>>>>> On Jun 30, 2016, at 4:05 PM, Dave Abrahams via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>>>>>> on Thu Jun 30 2016, Erica Sadun <erica-AT-ericasadun.com >>> <http://erica-at-ericasadun.com>> wrote: >>> >>>>>>> >>> >>>>>>>>> On Jun 30, 2016, at 4:41 PM, Dave Abrahams < >>> dabrah...@apple.com> wrote: >>> >>>>>>>>>> I mentioned this in a comment on the gist already, but I'm >>> really not >>> >>>>>>>>>> digging the "array" in `arraySpacing`. We've already moved >>> from top-level >>> >>>>>>>>>> "stride" to "memory layout spacing," gaining plenty of >>> clarity. I'm >>> >>>>>>>>>> skeptical that the "array" adds anything more. Moreover, it >>> muddies the >>> >>>>>>>>>> waters by mentioning a specific type (Array) in a context >>> where you're >>> >>>>>>>>>> querying the memory layout properties of another type. >>> >>>>>>>>> >>> >>>>>>>>> OK, I agree with that. If we have “alignment” rather than >>> >>>>>>>>> “defaultAlignment,” I suppose we can have plain “spacing.” >>> >>>>>>>> >>> >>>>>>>> No way to last-second sell you on interval rather than spacing? >>> >>>>>>> >>> >>>>>>> If you can explain why it's better. >>> >>>>>>> >>> >>>>>>>> // Returns the least possible interval between distinct >>> instances of >>> >>>>>>>> /// `T` in memory. The result is always positive. >>> >>>>>>> >>> >>>>>>> For me, “interval” doesn't go with “size” and “alignment,” which >>> are all >>> >>>>>>> about physical distances and locations. There are all kinds of >>> >>>>>>> “intervals,” e.g. time intervals. >>> >>>>>> >>> >>>>>> Hmm. Sounds like stride to me. stride or byteStride? >>> >>>>>> >>> >>>>>> James >>> >>>>> >>> >>>>> FAQ: "Why aren't you using the obvious phrase `stride` for >>> something that clearly >>> >>>>> returns the memory stride?" >>> >>>>> >>> >>>>> ANSWER: "As stride already has a well-established meaning in the >>> standard library, >>> >>>>> this proposal changes the name to spacing, providing a simple but >>> correct name that >>> >>>>> works well enough in its intended use. Measuring memory is >>> sufficiently esoteric >>> >>>>> that we prefer to reserve `stride` for a more common use case." >>> >>>> >>> >>>> Counter: some words have more than one well established meaning when >>> >>>> used in different contexts. 'spacing' isn't too bad here (much >>> better >>> >>>> than 'arraySpacing') but sticking to the term of art 'stride' would >>> be >>> >>>> best IMO. As James mentioned, spacing implies empty space *between* >>> >>>> items whereas stride matches the meaning of this property *exactly* >>> >>>> (which is why it is the term of art). >>> >>>> >>> >>>> If a programmer can't distinguish between a 'stride' property on >>> >>>> MemoryLayout and the 'stride' function they probably have no >>> business >>> >>>> doing anything which requires use of MemoryLayout in the first >>> place. >>> >>> >>> >>> I don't believe that “stride” *is* the accepted term of art for this >>> >>> meaning. I never heard of the idea of types having an intrinsic >>> >>> “stride” until I arrived on the Swift project. That usage came from >>> >>> “strideof.” >>> >>> >>> >>> If you all swear up and down that you've been talking about “the >>> stride >>> >>> of a type” for more than 2 years, I won't fight you on this. >>> >>> Otherwise... well, I still won't fight; I'm being crushed by an >>> >>> avalanche of bikesheds and I can't muster the energy ;->... but I'll >>> >>> forever be plagued by doubts about the name. >>> >> >>> >> I was just throwing in my 2 cents and planned to leave it at that. >>> >> The primary reason I chimed in is because I didn’t find the rationale >>> >> in the “answer” compelling. This isn’t something I feel like bike >>> >> shedding any further over either. >>> >> >>> >> https://en.wikipedia.org/wiki/Stride_of_an_array >>> >> >>> >> Maybe stride isn’t as common as I thought it was (if it was I’m sure >>> >> you would have heard of it before Swift) but it certainly predates >>> >> Swift in usage. >>> > >>> > But that's actually a different meaning altogether. Two “arrays” of >>> > type T can have different strides. They're talking about taking a view >>> > onto an underlying series of contiguous Ts that (potentially) skips >>> over >>> > elements. >>> >>> Maybe I come from an esoteric part of the universe. While I’ve never >>> heard of stride applied to a type, in particular, the concept of stride as >>> I know it applies to any item as laid out in memory, and seems to me to >>> apply equally well to any “object” in the loosest form of the word. I >>> believe my first experience with it, some 30 years ago, dealt with the row >>> stride in a frame buffer or bitmap. This meaning is similar to the array >>> reference as above. I disagree that they’re not in that article above >>> talking primarily about the same thing that we are: their very first >>> example, under the “Padding” headline, seems to exactly match our intent. >>> Their additional examples are just hacks/extensions of this concept. >>> >>> If we were talking about waveforms we’d be talking about period. Stride >>> indicates the same thing with regard to items in memory: how long a step do >>> you need to take to get from the start of one item to the start of the >>> next. So we could use “period”, or “interval”, or “step”, or something. I’m >>> just arguing that the most recognizable word to describe this concept, as >>> applied to any sort of item in memory, is stride. But again, maybe that’s >>> just based on my own experience. >>> >>> Ultimately, I’m sure it’s not a big deal. I agree with Mathew that >>> people using MemoryLayout aren’t likely to confuse the two uses within >>> swift. It’s just that if I had to describe the concept we’re describing in >>> MemoryLayout, stride would be my first choice, as it seems most apt. Short >>> of that, I’m sure that I could read comments and ultimately figure out that >>> “interval,” or “spacing,” or whatever, really means “stride” ;) >>> >>> James >>> >>> >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> >> >> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org >> https://lists.swift.org/mailman/listinfo/swift-evolution >> >
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