package `in`.xyz

fun <A, B> ((A)->B).optionalApply(optional: A?): B? {
    return optional?.let(this) // "let" good for 1 arg 
}
// test
fun testfun1(i: Int) = i + 1
testfun1.optionalApply(null) // "Function invocation expected" on "testfun1"

in

containsKey(..)

HashMap

ConcurrentHashMap

Map

val nejkulaťoulinkatějšíKolečko = Circle(5f, 5f, 10f)

remote.foo != null && remote.foo != local.foo

remote.foo != local.foo ?: false

println("getMember($name)")
        when (name) {
            "toString" -> return { obj.toString() }
            "valueOf" -> return {
                when (obj) {
                    is JsonNull -> null
                    is JsonArray -> obj.toString()
                    is JsonPrimitive ->
                        if (obj.isNumber) obj.asNumber
                        else if (obj.isBoolean) obj.asBoolean
                        else obj.asString
                    else -> obj.toString()
                }
            }
            else -> {
                try {
                    return obj[name!!]
                } catch (e: NoSuchElementException) {
                    return null
                }
            }
        }

val p = item.p
if (p != null) {
} else {
  executeSomething()
}

val

if