Infix function with when - is it possible?

is it possible to use infix function with when statement. Something similar to this:

infix fun Int.isGreater(value: Int): Boolean = this > value


and then:

when (value)
isGreater 2 -> doSomething()
isGreater 1 -> doSomethingElse()
else -> doNothing()



infix

2 Answers
2

Actually: no, this will not work. The reason can be seen when consulting the when grammar, which doesn't have a construct that takes the value given to when and calls functions of the whenCondition on it. So it doesn't have to do with the infix itself (while it is true that it needs a receiver on the left).

when

when

whenCondition

infix

What you could do is the following:

when {
value isGreater 2 -> ...
value.isGreater(1) -> ...


If you like, you can also read more about when in the Kotlin reference.

when

You cannot call infix functions like you do. It always needs a receiver on the left side:

when
value isGreater 2 -> doSomething()
value isGreater 1 -> doSomethingElse()
else -> doNothing()



Note that infix functions always require both the receiver and the parameter to be specified. When you're calling a method on the current receiver using the infix notation, you need to use this explicitly; unlike regular method calls, it cannot be omitted.

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