Nikolay Lunyak
34 lines
791 B
Kotlin
Vendored
34 lines
791 B
Kotlin
Vendored
// !LANGUAGE: +ContextReceivers
|
|
|
|
class File(name: String)
|
|
interface InputStream
|
|
|
|
interface AutoCloseScope {
|
|
fun defer(closeBlock: () -> Unit)
|
|
fun close()
|
|
}
|
|
class AutoCloseScopeImpl : AutoCloseScope {
|
|
override fun defer(closeBlock: () -> Unit) = TODO()
|
|
override fun close() = TODO()
|
|
}
|
|
|
|
context(AutoCloseScope)
|
|
fun File.open(): InputStream = TODO()
|
|
|
|
fun withAutoClose(block: context(AutoCloseScope) () -> Unit) {
|
|
val scope = AutoCloseScopeImpl() // Not shown here
|
|
try {
|
|
with(scope) { block<!NO_VALUE_FOR_PARAMETER!>()<!> }
|
|
} finally {
|
|
scope.close()
|
|
}
|
|
}
|
|
|
|
fun test() {
|
|
withAutoClose {
|
|
val input = File("input.txt").open()
|
|
val config = File("config.txt").open()
|
|
// Work
|
|
// All files are closed at the end
|
|
}
|
|
} |