BackpressureChannel has a control mechanism that allows consumer to influence the producer. There is a back pressure channel. Protocol: sender

Callback[A] is a function that takes A and error. A is only valid if error is nil.

Closable is a value that is accompanied with the Close(). This is an internal structure that should not be used outside of the resource package.

ClosableIO is a simple resource that implements Close method.

Collector reads the stream and produces some value.

Consumer can receive an instance of A and perform some operation on it.

Continuation represents some multistep computation. It is being used to avoid stack overflow. It's a universal way to do "trampolining".

Either is a simple data structure that can have either left value or right value.

ExecutionContext is a resource capable of running tasks in parallel. NB! This is not a safe resource and it is not intended to be used directly.

Fiber[A] is a type safe representation of Go routine. One might Join() and receive the result of the go routine. After Close() subsequent joins will f

GoResult[A] is a data structure that represents the Go-style result of a function that could fail.

IO[A] represents a calculation that will yield a value of type A once executed. The calculation might as well fail. It is designed to not panic ever.

Number is a generic number interface that covers all Go number types.

Option[A] can represent a value or an absent value of type A.

Pair is a data structure that has two values.

Pipe is a conversion of one stream to another. Technically it's a function that takes one stream and returns another.

Predicate is a function with a boolean result type.

Resource[A] is an structure that can only be _used_ via Use. Unfortunately, it's not an interface, because interface methods do not support generics a

ResultOrContinuation is either a final result (value or error) or another continuation.

Runnable is a computation that performs some side effect and takes care of errors and panics. It task should never fail. In case it fails, application

Set is a map with a dummy value.

Sink is a pipe that does not return meaningful values.

StepResult[A] represents the result of a single step in the step machine. It might be one of - empty, new value, or finished. The step result also ret

Stream is modelled as a function that performs a single step in the state machine.

Fields should be checked in order - If Error == nil, If !IsFinished, then Value

Unit is a type that has only a single value.

if result is already available, there is no need to use callbacks channel. The result will be immediately delivered.