[swift-evolution] [SHORT Review] SE-0132: Rationalizing Sequence end-operation names

[Nevin Brackett-Rozinsky]

Whoops, hit reply too soon. Please consider the following inserted in the
gap in my last email:

2. We're not comfortable with heavily overloading a property with a bunch
> of methods, and didn't want to make `first` and `last` into methods.


I am okay with this overload precisely *because* the functionality is so
similar.


3. Most APIs work fine, but `hasFirst(_:)` is atrocious, and we see no
> better alternative which includes the word `first`.


Agreed. Both `starts(with:)` or `hasPrefix(_:)` are much better, and I
would be happy with either.


…and I seem to have cut off a sentence at the end of my last email:

Something like `prefix(limit: n)` is more descriptive than the bare
`prefix(n)` form, however in my view it still falls short of clarity
achieved by `first(n)`.

Nevin


On Tue, Jul 26, 2016 at 7:16 PM, Nevin Brackett-Rozinsky <
nevin.brackettrozinsky at gmail.com> wrote:

> * We considered using `first` and `last` as the basis for both
>>    single-element and multiple-element operations (such that `prefix(3)`
>>    would become `first(3)`, etc.), but:
>>
>
>
>    1. These seemed like distinct functionalities, particularly since
>>       their types are different.
>
>
> I think the functionality of “Please give me the first 1 element” is
> extremely similar to “Please give me the first n elements”.
>
>
>
>
> Keeping those issues in mind, do you still prefer `first(n)` over
>> `prefix(n)`?
>
>
> In my subjective opinion, `.first`, `.first(n)`, and `starts(with: [1, 2,
> 3])` are crystal-clear at the use site, and coexist just fine.
> Additionally, `hasPrefix([1, 2, 3])` is equally clear and I would be fine
> with that—in particular I am fine with the “get” and “test” methods using
> different words.
>
> By contrast, I find `prefix(n)` to be unclear about the role of `n`.
> Something like `prefix(limit: n)`
>
>
> On Tue, Jul 26, 2016 at 3:46 PM, Brent Royal-Gordon <
> brent at architechies.com> wrote:
>
>> > On Jul 26, 2016, at 8:30 AM, Nevin Brackett-Rozinsky <
>> nevin.brackettrozinsky at gmail.com> wrote:
>> >
>> > However, I believe that `first(n)` and `last(n)` read more clearly at
>> the point of use than `prefix(n)` and `suffix(n)`.
>>
>> I've seen this a couple of times. It's something I bring up in "Other
>> alternatives":
>>
>> > * We considered using `first` and `last` as the basis for both
>> >   single-element and multiple-element operations (such that `prefix(3)`
>> >   would become `first(3)`, etc.), but:
>> >
>> >   1. These seemed like distinct functionalities, particularly since
>> >      their types are different.
>> >
>> >   2. We're not comfortable with heavily overloading a property with a
>> >      bunch of methods, and didn't want to make `first` and `last` into
>> >        methods.
>> >
>> >   3. Most APIs work fine, but `hasFirst(_:)` is atrocious, and we see
>> >      no better alternative which includes the word `first`.
>>
>> To give you an idea of what I mean by #3:
>>
>>         if numbers.hasFirst([1, 2, 3, 4, 5]) && numbers.hasLast([5, 4, 3,
>> 2, 1]) { … }
>>
>> Keeping those issues in mind, do you still prefer `first(n)` over
>> `prefix(n)`?
>>
>> --
>> Brent Royal-Gordon
>> Architechies
>>
>>
>
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