If needs else branch in expression of type Unit

roschlau · June 6, 2018, 7:54am

I don’t think special treatment of if in such a special edge case is justified. Kotlin tries to push you toward immutability and reducing side effects, and a when expression with a Unit return type just screams “SIDE EFFECT”. Sure, a lot of the time you can’t avoid those cases, but I’m not sure the language should actively encourage them. I think having a little more verbosity in a case like this is quite acceptable, because it makes inadvertently creating side effects harder.

Topic		Replies	Views
If operator in function expression Language Design	9	4459	March 28, 2018
‘when’ expression requires to be exhaustive, even be 'else' branch is empty Language Design	5	3309	April 18, 2023
[SOLVED] 'when' expression recommended to be exhaustive, even if it is impossible to reach the else branch Language Design	3	18330	April 12, 2018
Using an "else-less if" as an expression should not compile	4	2561	August 9, 2015
Returning a when needs else, but using just when (without return) doesn't Language Design	4	871	February 25, 2022

If needs else branch in expression of type Unit

Related topics