Streams in node.js 10.x → Syndicate

Streams can be in binary or object mode

Desiderata: Like enumerator/observable, it seems like readable/writable should be duals. If they're not, why not, other than historical reasons?

GENERAL

stream.finished()

Has a buffer of to-be-accepted elements.

Emits:

close (optional), after all resources have been released. No more events, no more computation, nothing more will happen.
drain, when the buffer runs empty, to signal a demand for more input.
error
finish, exactly equivalent to a callback-function acknowledging the end() call: the "no more input is available" signal has been completely processed and has made its way through to the underlying/backing medium.
pipe/unpipe, notifies the Writable of an attached/detached pipe sender.

Methods:

cork/uncork, for batching supplied inputs
destroy, abandon the Writable without bothering to try to finish; dual to error, more or less
end, does an optional write and then signals the clean end of the input stream. If a callback is supplied, it is attached as a listener to finish.
write, delivers a chunk of input. Yields false when the buffer is full at the time the call to write returns; will issue drain later in this case.

Properties:

Has a buffer of to-be-relayed elements.

Emits:

close (optional), exactly the same as for Writable.
readable, when the buffer becomes nonempty from having been empty, to signal the possibility of more output.
error
end, when no more data will be produced; analogous to TCP's FIN. Is in-order wrt other data.
data, delivers a chunk of output.

Methods:

pipe/unpipe, for attaching a Writable to this Readable. Many of them can be attached! I guess that makes a fan-out? By default, the end method of the Writable is called when the Readable emits its end event, but this can be overridden with an option.
isPaused, pause and resume control and interrogate XON/XOFF-style flow control.
destroy, abandon the Readable without bothering to try to finish reading from it; not quite dual to error since a Readable is a source, not a sink
read, explicitly get a chunk
push, internal API for poking a chunk into the "last-in" end of the FIFO to-be-delivered buffer. Returns false when the buffer is (over-)full.
unshift, internalish API for poking a chunk into the "first-in" end of the FIFO buffer, like ungetc() etc. There are complications in using this, check the docs.

Properties: