tap

In std/io.

effectful fn tap<F : Format, T>(endpoint: Readable, format: Type<F>) : Stream<T>
effectful fn tap<F : Format, T>(id: String, format: Type<F>) : Stream<T>

The documents read from endpoint in format, one held at a time, as a Stream<T>. A format that is one whole document, such as Text, is a type error. tap(id) gives the elements of the finite source configured under id as a Stream; tap(c) of a Channel<T> gives each value as it is written; tap(file(path).end, F) follows what is appended. Effectful: it runs once, where it is written.