Formatting with many generics

[PaulWoitaschek]

I have a function with a lot of generics. I can't make intellij autoformat it in a way t hat ktlint stops complaining.
I installed the settings for intellij ktlint --apply-to-idea-project --android . However it complains about the intendation.

package my.package

import io.reactivex.Observable
import io.reactivex.ObservableSource

inline fun <T1 : Any, T2 : Any, T3 : Any, T4 : Any, T5 : Any, T6 : Any, T7 : Any, T8 : Any, T9 : Any, T10 : Any, T11 : Any, T12 : Any,
  T13 : Any, T14 : Any, R : Any>
  combineLatest(
  source1: ObservableSource<T1>,
  source2: ObservableSource<T2>,
  source3: ObservableSource<T3>,
  source4: ObservableSource<T4>,
  source5: ObservableSource<T5>,
  source6: ObservableSource<T6>,
  source7: ObservableSource<T7>,
  source8: ObservableSource<T8>,
  source9: ObservableSource<T9>,
  source10: ObservableSource<T10>,
  source11: ObservableSource<T11>,
  source12: ObservableSource<T12>,
  source13: ObservableSource<T13>,
  source14: ObservableSource<T14>,
  crossinline combiner: (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14) -> R
): Observable<R> {
  return Observable.combineLatest<Any, R>(
    arrayOf(
      source1,
      source2,
      source3,
      source4,
      source5,
      source6,
      source7,
      source8,
      source9,
      source10,
      source11,
      source12,
      source13,
      source14
    )
  ) {
    @Suppress("UNCHECKED_CAST")
    combiner(
      it[0] as T1,
      it[1] as T2,
      it[2] as T3,
      it[3] as T4,
      it[4] as T5,
      it[5] as T6,
      it[6] as T7,
      it[7] as T8,
      it[8] as T9,
      it[9] as T10,
      it[10] as T11,
      it[11] as T12,
      it[12] as T13,
      it[13] as T14
    )
  }
}

If you run ktlint, it fails:

/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:9:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:10:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:11:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:12:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:13:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:14:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:15:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:16:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:17:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:18:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:19:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:20:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:21:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:22:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:23:3: Unexpected indentation (expected 4, actual 2)
/home/ph1b/Dev/Yazio/features/rx/src/main/java/com/yazio/android/rx/T.kt:24:1: Unexpected indentation (expected 2, actual 0)

[shyiko]

Yeah, unless combineLatest is kept on the same line as <T1 : Any, ..., R : Any> IntelliJ appears to format things differently. Two options until it's fixed:

• move combineLatest to the prev line (unless I'm missing something "TN : Any" can be simplified to TN)

inline fun  <T1, ..., R> combineLatest(
	...

• or

/* ktlint-disable parameter-list-wrapping */
inline fun <T1 : Any, ...>
	combineLatest(
		...

[PaulWoitaschek]

Two options until it's fixed

Who fixes this? Is this a ktlint or an intellij issue?

unless I'm missing something "TN : Any" can be simplified to TN

I explicitly want the upper bound to be of type Any.
combineLatest<Observable<Int?>>... should fail to compile.

[shyiko]

Who fixes this? Is this a ktlint or an IntelliJ issue?

Ideally, IntelliJ would allow

inline fun <
  T1 : Any, 
  T2 : Any, 
  ...
> combineLatest(
  source1: ObservableSource<T1>,
  source2: ObservableSource<T2>,
  ...
) {
  ...
}

In this case, no changes would be needed in ktlint.

We could add a workaround on ktlint side to accept

inline fun <T1 : Any, ...>
  combineLatest(
  source1: ObservableSource<T1>,
  ...

but, personally, I don't think that's a good idea. It's inconsistent at best.

I explicitly want the upper bound to be of type Any.

Got it.

P.S. there is a way to force IntelliJ to skip reformatting certain regions - https://stackoverflow.com/a/23485817/482225.

[romtsn]

Not sure if this is still an issue with the new indentation rule promoted from experimental, and just landed #769, I will close this for now, feel free to reopen if it's still a problem