node.js + express.js + bacon.js -> wrap express.js in functional reactive programming

app.coffee

express = require("express")
Bacon = require("baconjs")
app = express()


route = (app) -> (path) ->
  bus = new Bacon.Bus()
  app.get path, (req,res) ->
    bus.push
      req: -> req
      res: -> res
  bus

#app.get "/hello.txt", (req, res) ->
app2 = route(app)

r1 = app2('/hello/:a.txt')

incr = (n) -> Bacon.fromCallback (next) ->
  fn = -> next(parseInt(n) + 1)
  setTimeout fn,3000


map_data = (con) ->
  con.incr_a = incr con.req().params.a
  Bacon.combineTemplate con

r1.filter( (con) -> con.req().params.a == '1' ).flatMap(map_data).log().onValue (con) -> con.res().end con.incr_a.toString()
r1.filter( (con) -> con.req().params.a != '1' ).onValue (con) -> con.res().end con.req().params.a

app.listen 3000
console.log "Listening on port 3000"