pull-monad
v1.1.1
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pull-monad
Monadic functions for pull-streams
These are the methods that make something "monadic." These functions and their interactions with each other satisfy the laws laid out in fantasy-land.
Usually these methods exist on the protytpe and are used like so:
const lift2 = (f, a, b) => b.ap(a.map(f))
Because these are simply through
's, though, they must be used as such:
const lift2 = (f, a, b) => pull(b, ap(pull(a, map(f))))
example
const pull = require('pull-stream')
const { map, of, ap, chain } = require('pull-monad')
const plus1 = x => x + 1 // takes a number and returns a number
const times7 = x => x * 7 // takes a number and returns a number
const triplicate = x => pull.values([x, x, x]) // takes a number and returns a stream
pull(
lift2(a => b => a + b, of(1), of(2)),
map(times7),
chain(triplicate),
ap(of(plus1)),
pull.collect((err, arr) => console.log(arr)))
// => [22, 22, 22]