Did I just find a bug with the Kotlin compiler? The following example throws an error at line 4: `'i...

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[spnda]

Did I just find a bug with the Kotlin compiler?
The following example throws an error at line 4:
'if' must have both main and 'else' branches if used as an expression

fun exampleFunc(someBoolean: Boolean) = when (someBoolean) {
    else -> {
        val otherBoolean = Random.nextBoolean()
        if (otherBoolean) {
            print("Yay!")
        }
    }
}

It seems to think it is a ternary, I guess.

[kqr]

isn't that because last expression is implicit return?

[Adam Powell]

Specifically because you've defined the function as an expression using = when

[spnda]

if (otherBoolean) {
    val t = 1
}

yet this wouldn't be a implicit return, yet it still throws the same error

@Adam Powell, I guess...

[Adam Powell]

The contents of the if block don't matter, without an else it's not a valid expression

[Rob Elliot]

if (otherBoolean) {
    val t = 1
}

is a statement, it doesn’t need an else

val t = if (otherBoolean} {
  1
}

is an expression, so it needs an else branch to know what to evaluate t to if otherBoolean is false.

In your when, the when needs to be an expression to return a value from the function, so the `when`’s else block needs to be an expression, so the `if`/`else` needs to be an expression.

[Stephan Schroeder]

with = when(...) { Kotlin assumes that a returnvalue is supposed to be given back. But using a multistatement-method form works

fun exampleFunc(someBoolean: Boolean) {
  when (someBoolean) {
    else -> {
      val otherBoolean = Random.nextBoolean()
      if (otherBoolean) {
        print("Yay!")
      }
    }
  } 
}

[Rob Elliot]

edited: Apologies, misread your post