What is the more concise way to write

if (arg == null) null else myfun(arg)

? I can only think of

arg?.let { myfun(it) } ?: null

but this seems less readable to me.

arg?.let(::myFun)

You don’t need

?:

ah yes, in this case

arg?.let { myfun(it) }

so would

let

be the appropriate function to use?

if you need a concise way, yes

Ok, thanks. I wonder about creating an extension function:

MyArgClass.myfun() = this?.let {myfun(this)}

so I can then do

arg?.myfun()

?

depends on case I suppose. If you have a lot of such usages, why not. It’s like any other

toSomething

functions, including stdlib

Another alternative would be to let

myfun()

accept a null arg and return null in that case. Is there some general way (contracts?) that a function can declare that a null arg will return null result?

IMHO if a function accepts a

null

it should deal with it more intelligently than returning another

null

immediately. In your situation an extension on a not-null type is the most obvious way IMO

arg?.myFunc()

I think

run

instead of

let

looks more concise

you cannot use run with method reference