staticland monads

reader.js

const Reader = {
  of: a => { return _ => a },
  map: f => run => {
    return x => f(run(x))
  },
  contramap: f => run => { 
    return x => run(f(x))
  },
  chain: f => run => {
    return x => f(run(x))(x)
  },
  run: x => run => run(x)
}
pipe(
  Reader.map(x => x * 2),
  Reader.chain(x => Reader.of(x * 10)),
  Reader.run(3)
)(x => x) //=> 60

task.js

const stringise = f => str => {f.toString = () => str; return f}
const Task = {
 of: x => stringise((rej, res)=>{ res(x)})(`Task(${x})`),
 empty: () =>{},
 map: f => fork => (rej, res) => fork(rej, x=>res(f(x))),
 chain: f => fork => (rej, res) => fork(rej, data => f(data)(rej, res)),
 run: (err, success) => fork => fork(err, success) 
}

pipe(
    Task.of
  , Task.map(i=>i+1)
  , Task.chain(i => Task.of(i*8))
  , Task.run(console.error, console.log)
)(999)

Task.of(3)