An element of the CoroutineContext. An element of the coroutine context is a singleton context by itself.

interface Element : CoroutineContext

Key for the elements of CoroutineContext. E is a type of element with this key.

interface Key<E : Element>

Accumulates entries of this context starting with initial value and applying operation from left to right to current accumulator value and each element of this context.

abstract fun <R> fold(
    initial: R, 
    operation: (R, Element) -> R
): R

Returns the element with the given key from this context or null.

abstract operator fun <E : Element> get(key: Key<E>): E?

Returns a context containing elements from this context, but without an element with the specified key.

abstract fun minusKey(key: Key<*>): CoroutineContext

Returns a context containing elements from this context and elements from other context. The elements from this context with the same key as in the other one are dropped.

open operator fun plus(
    context: CoroutineContext
): CoroutineContext

An empty coroutine context.

object EmptyCoroutineContext : CoroutineContext, Serializable