Who says it’s useful only for beginners?
The way I see it, it’s about expressivity. What conveys the intention better
when you want to do something 10 times? `10.times { … }` or an iteration over a
range from 0 to 10?
— Radek
> On 18 Dec 2015, at 20:13, Félix Cloutier via swift-evolution
> <[email protected]> wrote:
>
> It doesn't need to be an underscore, but when it is not, the compiler emits
> an educative warning steering you towards _:
>
> /tmp/test.swift:3:7: warning: immutable value 'i' was never used; consider
> replacing with '_' or removing it
>
> You can also use inclusive ranges instead if you're more comfortable with
> that: 1...5000 will do just that.
>
> I don't mean to come across as dismissive, and I'm all for an inclusive Swift
> that you can pick up without knowing advanced concepts. However, there is
> definitely value in helping people learn, and learning always moves you a
> little bit out of your comfort zone. When do we remove the training wheels?
> How long can we hide the fact that indices usually start at 0? How long
> before you need to iterate an array using the same range-based for loop?
>
> I spend a lot of time on Stack Overflow and I've seen lots of beginners ask
> for lots of things, but the people who ask about the for loop are usually
> people with a background in another C-like language who try to use the
> arguably less readable C-like for loop. I've never seen anyone before say
> that it looks unclean or unreadable.
>
>> Le 18 déc. 2015 à 13:38:59, Cihat Gündüz via swift-evolution
>> <[email protected] <mailto:[email protected]>> a écrit :
>>
>> I agree with both of you about the alternative implementations.
>>
>> That’s exactly what I’d love to see integrated to the standard library like
>> Ruby is here:
>> http://ruby-doc.org/core-2.2.4/Integer.html#method-i-times
>> <http://ruby-doc.org/core-2.2.4/Integer.html#method-i-times>
>>
>> My main problem is that it neither looks clean nor readable especially for
>> beginners that there is an underscore in the closure. Also beginners often
>> get confused with the number of times some code is run when starting to
>> count from 0 which is also why I think it shouldn’t appear. The .times
>> method would solve both of these problems.
>>
>>> Am 18.12.2015 um 19:33 schrieb Etan Kissling <[email protected]
>>> <mailto:[email protected]>>:
>>>
>>> (or with a for in loop -- but i guess you have a reason for using .foreach)
>>>
>>> for _ in 0..<5_000 {
>>> print("asdf")
>>> }
>>>
>>>
>>>> On 18 Dec 2015, at 19:31, Etan Kissling via swift-evolution
>>>> <[email protected] <mailto:[email protected]>> wrote:
>>>>
>>>> You don't need stride for this.
>>>>
>>>> func foo() {
>>>> (0..<5_000).forEach { _ in
>>>> print("asdf")
>>>> }
>>>> }
>>>>
>>>>
>>>>> On 18 Dec 2015, at 19:25, Cihat Gündüz via swift-evolution
>>>>> <[email protected] <mailto:[email protected]>> wrote:
>>>>>
>>>>> Dear Swift-Community,
>>>>>
>>>>> I’d like to propose an addition of a useful method, especially for
>>>>> beginners that also makes Swift much more readable in some situations:
>>>>> The addition of a .times method to Integer type(s).
>>>>>
>>>>> For example recently in one of my projects I wanted to test the
>>>>> scalability of an important piece of code and wrote this method:
>>>>>
>>>>> func testPerfQualityInPercentWithoutQualityImprovements() {
>>>>> self.measureBlock {
>>>>> let expectedQuality = 33.33
>>>>> 0.stride(to: 5_000, by: 1).forEach { _ in
>>>>>
>>>>> XCTAssertEqualWithAccuracy(self.crossword.qualityInPercent,
>>>>> expectedQuality, accuracy: 0.1)
>>>>> }
>>>>> }
>>>>> }
>>>>>
>>>>> As you can see what I basically wanted was to repeat the test some
>>>>> thousand times. I also like to use the Ruby language and one thing I love
>>>>> about it is that it has some really handy methods integrated to the
>>>>> language in situations like this which make the code very readable and
>>>>> therefore fun to use.
>>>>>
>>>>> I’m an even bigger fan of Swift so I’d love to see such useful methods
>>>>> appear in Swift, too and this is the first I came across that I really
>>>>> missed. So I’m asking myself, what if I could write the same code above
>>>>> like this:
>>>>>
>>>>> func testPerfQualityInPercentWithoutQualityImprovements() {
>>>>> self.measureBlock {
>>>>> let expectedQuality = 33.33
>>>>> 5_000.times {
>>>>>
>>>>> XCTAssertEqualWithAccuracy(self.crossword.qualityInPercent,
>>>>> expectedQuality, accuracy: 0.1)
>>>>> }
>>>>> }
>>>>> }
>>>>>
>>>>> I think it could be added to the Swift standard library very easily (for
>>>>> example by using the .stride method like I used) without any side effects
>>>>> and has enough advantages to be part of Swift itself. What do you think?
>>>>>
>>>>> I wish you all the best,
>>>>> Cihat
>>>>>
>>>>>
>>>>> P.S.: This is my very first mail in such a mailing list so I did
>>>>> everything correctly. ^.^
>>>>>
>>>>>
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>>>>
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