withoutFirst() withoutLast() -Thorsten
> Am 29.12.2015 um 21:43 schrieb Kevin Ballard via swift-evolution > <swift-evolution@swift.org>: > > Actually that's not true, CollectionType does not define dropFirst(). It > merely provides a default implementation. dropFirst() is only actually > defined in SequenceType, which does not have any mutating methods. Renaming > it to "removingFirst()" would be against the guidelines for all sequences > that are not also RangeReplaceableCollectionTypes. > > -Kevin Ballard > > On Tue, Dec 29, 2015, at 12:39 PM, Daniel Duan wrote: >> I made the same observation on Haskell in the original post :) >> >> “removeFirst()” is also defined in CollectionType. So “dropFirst()” is >> removeFirst()’s – in the Guidelines’ term – "non-mutating counterpart" for >> all CollectionTypes. Therefore, “removingFirst()” would be the winner. >> >> (My personal preference notwithstanding, that is). >> >>> On Dec 29, 2015, at 12:15 PM, Kevin Ballard <ke...@sb.org> wrote: >>> >>> I guess that's a good argument for keeping "prefix" and "suffix" instead of >>> "take" and "takeEnd". But there is no good noun phrase to use for >>> dropFirst/dropLast (Haskell's "init" and "tail" are nouns but they're very >>> confusing and don't really make sense once you add in an integral argument >>> anyway). The guidelines do say it's acceptable to use an imperative verb if >>> there is no good noun phrase, so "skip" and "skipEnd" (or "skipLast", or >>> maybe "skipSuffix" if we're keeping "suffix") are still reasonable. >>> >>> Incidentally, it occurs to me that "removingFirst" is actually not an >>> appropriate name here, because dropFirst is a method of SequenceType, and >>> SequenceType does not have mutating methods. removeFirst is actually >>> defined by RangeReplaceableCollectionType (and by Set, and also by >>> CollectionType if SubSequence == Self). >>> >>> -Kevin Ballard >>> >>> On Tue, Dec 29, 2015, at 11:55 AM, Daniel Duan wrote: >>>> Hi Kevin, >>>> >>>> “take" and “skip” are fine as free function names. As method names, they >>>> are a step back from following the API Guidelines (“non-mutating methods >>>> should read as noun phrases”). >>>> >>>> - Daniel >>>> >>>>> On Dec 29, 2015, at 11:40 AM, Kevin Ballard via swift-evolution >>>>> <swift-evolution@swift.org> wrote: >>>>> >>>>> On Mon, Dec 28, 2015, at 04:23 PM, Kevin Ballard wrote: >>>>>> That said, `droppingFirst` sounds pretty weird to me. "drop" (and the >>>>>> related verb "take" that we're not using) has precedent in multiple >>>>>> languages (Rust and Haskell come to mind) to mean "return a new sequence >>>>>> that skips the first N elements". And I'm not aware of any language that >>>>>> sets precedent for the verb "drop" to mean "mutate the receiver". >>>>> >>>>> Hmm, I just took a look, and while Rust does use "take", it actually >>>>> doesn't use "drop" (but Haskell does). Instead it uses "skip", which >>>>> seems like a good candidate if we're going to rename this. I'm tempted to >>>>> say we should use "take" instead of "prefix" as well, because >>>>> `seq.prefix(3)` isn't actually immediately obvious what it does (as the >>>>> verb "prefix" usually means to add onto the front, not to take the >>>>> front). And we can use "takeLast" for "suffix" (neither Rust nor Haskell >>>>> appears to have an equivalent of takeLast; I believe Rust doesn't because >>>>> none of its iterator adaptors use dynamically-allocated memory, and I >>>>> think Haskell expects you to just do `reverse . take n . reverse`). >>>>> Although I do notice Haskell has a function dropWhileEnd that drops the >>>>> suffix, which suggests "takeEnd" and "dropEnd" here. >>>>> >>>>> Which is to say, if we're going to rename these methods, my vote is: >>>>> >>>>> prefix -> take >>>>> suffix -> takeEnd or takeLast >>>>> dropFirst -> skip >>>>> dropLast -> skipEnd or skipLast >>>>> >>>>> -Kevin Ballard >>>>> _______________________________________________ >>>>> 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 _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution
