Is there a way to shorter this `listOf(1) + listOf...

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[nil2l]

Is there a way to shorter this listOf(1) + listOf(2,3,4,5). Something like this 1 :: listOf(2,3,4,5).

[karelpeeters]

listOf(1,2,3,4,5) 🧌

[nil2l]

😑

[karelpeeters]

If this is something you have to do often you can can define something like this:

operator fun <T> T.plus(list: List<T>): List<T> =
    ArrayList<T>(list.size + 1).also { it.add(this); it.addAll(list) }

[nil2l]

This means ‘no’. Ok.

[karelpeeters]

Huh?

[nil2l]

Yeah, your solution works fine. I mean it’s not built-in one. Though it may be JB’s strategy..

[karelpeeters]

Ah I see. Actually the problem with my function is that it shadows Iterable<T>.plus(Iterable<T>), so it can cause unexpected behavior.

[nil2l]

Does it? Iterable<T>.plus(List<Iterable<T>>) would be shodawed.

[nil2l]

Also body can be shorter:
operator fun <T> T.plus(list: List<T>): List<T> = list + this

[karelpeeters]

That changes the other, and if you wanted that you could have done listOf(2,3,4,5) + 1 in the first palce.

[karelpeeters]

I'm not sure if it is shadowed actually, the compiler might pick T = Any and shadow it that way.

[nil2l]

Oh.. you’re right 🙂