Out of curiosity, is there a reason why the parent...

# announcements

[Luke]

Out of curiosity, is there a reason why the parentheses of a function without parameters are not optional?

[Shawn]

w/o parens it looks like a property, potentially

[Shawn]

Kotlin in general tries to avoid ambiguity

[Shawn]

imo function calls should be immediately apparent to the reader

[Ruckus]

Also, you could potentially run into ambiguity with the invoke operator.

fun test(op: Thing.() ->) {
    op  // Does this reference the value, or invoke the lambda?
}

[streetsofboston]

You can create some confusion by creating this extension function operator fun Type1.invoke(block: () -> Type2) : Type3 🙂

[streetsofboston]

For

fun test(op: Thing.() -> Unit) {
    op  // Does this reference the value, or invoke the lambda?
}

the op refers to the lambda value; you don’t invoke it. someThing.op() invokes it.

[Luke]

No, I didn’t mean when calling the function. Yes the call should absolutely use empty parentheses. I’m referring to the function definition. What if instead of defining fun foo() {...}, you could write fun foo {...}. I don’t see a confusion or ambiguity here

[streetsofboston]

Ah!
That would be indeed a little less typing and because of the fun keyword, it won't be ambiguous.
But somehow it looks odd/off to me....

[Luke]

Yeah, I got that feeling too, but it might just be a out of habbit. Like we’re so used to see functions declared with them that removing them feels odd but we could get used to that new way

[Luke]

Anyway, I’m just thinking out loud here