I suspect most people feel it should be inclusive I know I t

Question

I suspect most people feel it should be inclusive I know I think that way But obviously it s comfort and learning Just like Java s substring takes time to learn Generally people think it s inclusive of end index when it isn t

Dico · Answer

I think the use case for inclusive ranges is WAY less common than exclusive ranges I think it s a semantic decision assessing how best to distinguish between the two that resulted in this situation where most of the time you have to write `until` or `a b 1` Personally I find it very frustrating I think should represent an exclusive range because of the use case being so much more common It s counter intuitive with the style of indices starting at 0 rather than 1 But the window to change it has long faded

karelpeeters · Answer

Nearly every range is exclusive `subList` `random nextInt` the most common for loop is `0 size` exclusive etc I like what Rust did more ` ` is exclusive and ` =` is inclusive Too late to change now man shrugging

Mike · Answer

I think we can agree that both are very common It s whatever way you ve decided to approach it and subjective I also agree that the decision has been made

ghedeon · Answer

I don t think it s too late We just need to add ` lt ` Swift 0 5 amp 0 lt 5 I like it even more than Rust version

Dico · Answer

That s a great idea < ghedeon> I m happy to help with a KEEP

Dico · Answer

< Mike> when considering all languages both might be common I still think exclusive is more common though But in kotlin no inclusive ranges do not compare to exclusive ranges in terms of how common they are Moreover I would never even use `repeat` function if this design were the other way around

Mike · Answer

I m not seeing connection between repeat and substring I ve found people mess up substring in Java BECAUSE they think assume it s inclusive So it s opinion and YMMV situation all around I m happy to learn whatever the language I m using decides to have

karelpeeters · Answer

`repeat 10 println it ` is 0 to 10 exclusive too

Mike · Answer

I wasn t aware that `repeat` passed an index in Obviously it would be non intuitive if it was inclusive as it would repeat n+1 times

ghedeon · Answer

< Dico> could be something Have you done this before Any well written KEEP from the top of your head so we can follow the structure Let s push it

Dico · Answer

< ghedeon> well I wrote this KEEP But it hasn t had any answer from JB so probably not something to copy

Dico · Answer

But the general structure is motivation and then solution in this case and we re basically suggesting to add an `operator fun until` right

Dico · Answer

< Mike> the comparison is between `repeat 10 i gt ` and `for i in 0 10 ` I would prefer to write the latter but the problem is that it s not the same I d have to write `for i in 0 until 10 ` even though the exclusive range provided by `until` is a much more common use case

Dico · Answer

< ghedeon> This is probably a good place to start

Mike · Answer

Personally when I see 0 10 my brain instinctively thinks inclusive so 0 1 2 10 And now that I know `repeat` passes in the index I wouldn t be inclined to use `for i in 0 9 ` rather than `repeat 10 ` But I agree it s subjective and support submitting a KEEP if you feel that strongly about it Ultimately it s up to the Language team to decide

Dico · Answer

We re not going to suggest changing it that would break existing code But something like lt like < ghedeon> suggested should be considered

karelpeeters · Answer

< Dico> Kind of off topic but for what it s worth I really like that delegation proposal there s a lot of good ideas in there that are very necessary I hope it ends up getting somewhere

Dico · Answer

Thank you < karelpeeters> heart