Python Fetch Functor

fetch.py

import requests
import threading

# a -> ()
def out(x):
  print x
def get(url, cb):
  def work():
    cb(requests.get(url).json())
  return work

# (b -> c) -> (a -> b) -> a -> c
compose = lambda f, g: lambda x: f(g(x))

# type Fetch a = (a -> ()) -> ()
# String -> Fetch JSON
fetch = lambda url: lambda cb: threading.Thread(target=get(url, cb)).start()
# (a -> b) -> Fetch a -> Fetch b
fmap = lambda f: lambda r: lambda cb: r(compose(cb, f))

# Fetch JSON
fetchGist = fetch('https://api.github.com/gists/5b2bb0e6ef1fe7deb976')
# JSON -> String
getContent = lambda x: x['files']['poem.txt']['content']
# String -> ()
printLen = compose(out, len)
# Fetch ()
fetchContent = fmap(compose(printLen, getContent))(fetchGist)
# ()
fetchContent(lambda x: x)