Type Alias OutputSink 

pub type OutputSink = Box<dyn FnMut(ExecEvent) -> OutputFlow + Send>;

A callback for output. Only ExecEvent::Output is delivered; the result carries the exit status. Answering std::ops::ControlFlow::Break stops delivery, and the call still waits for and acks the exec, so nothing is left running unobserved (BIND-8).

Aliased Type

pub struct OutputSink(/* private fields */);