Trying to find a better pattern. Have some code l...

# announcements

[Ian]

Trying to find a better pattern. Have some code like this:

var s : String? = null
exec {
    s = createS()
}
s!!.doSomething()

the exec block is executed synchronously so s will be assigned to a non-null value, but the type system doesn’t know this hence the !!. createS() can only be called within the exec block.

Obviously the !! is ugly, I’m trying to figure out whether there is a better way to get s “out” of the inner code block. I could modify exec such that it will return whatever is returned by the code block, but what if I need to get multiple variables out of the code block?

[umar]

ianclarke: maybe you need to return data class from `exec`:

data class Data(val str: String, val num: Double)

So you can use as normal class:

val data = exec  {
  Data(str = createS(), num = createD())
}
data.str.doSomething()
data.num.doSomething()

Or destructure it immediately:

val (str, num) = exec  {
  Data(str = createS(), num = createD())
}
str.doSomething()
num.doSomething()

[Ian]

Yes, I’ve been playing around and I’m thinking that just returning a single value through exec might be sufficient - it constrains some things but possibly in a good way. Thanks for your help 🙂

[umar]

You're welcome