reference.md

River API Reference

These are a work-in progress.

Terms

term	meaning
iterator	An object that follows the Iterator Protocol.
reactor	Shorthand for an asynchronous iterator.
producer	An object that's either an iterator or reactor.
adapter	A function that transforms a value into a producer.
filter	A function that transforms a producer into another kind of producer.
reducer	A function that transforms a producer into an ordinary value, like an array or a number.
generic	A function that is polymorphic across one or more of its arguments.

Adapters

Adapters are functions that take a value and return a producer.

producer

producer value → producer

name	type	description
value	any	Any value intended to be transformed into a producer.
→ producer	producer	A producer (an iterator or reactor).

Example

assert isIterator (producer [])
assert isReactor (producer -> yield await null)

events

events name, source → reactor

name	type	description
name	string	The name of the event to produce.
source	object	The source of the events. Must have an on method for registering handlers.
→ reactor	reactor	A reactor that produces the named events from the source.

read

read stream → reactor

name	type	description
stream	stream	A readable stream-like object, with data, error, and end events.
→ reactor	reactor	A reactor that produces the data events from the stream.

union

flow

go

Filters

tee

map

project

accumulate

select

reject

compact

flatten

junction

fork

partition

take

limit

wait

lines

throttle

Reducers

start

each

collect

fold/reduce

foldr/reduceRight

any

all

zip

sum

average

delimit

write