example of Reader.T(Task) and express

func.js

const Task = require('data.task');
const { Reader, Maybe } = require('ramda-fantasy');
const ReaderTask = Reader.T(Task);
const R = require('ramda');
const express = require('express');

const app = express();

const MOCK_DB = {
	5 : {
		user: 'markus'
	}
};

const GLOBALENV = {
	db : {
		get(id) {
			const user = MOCK_DB[id];
			return user != null 
				? Task.of(user) 
				: Task.rejected({ code: 404, message: 'user not found'});
		}
	}
}

app.getF = function(route, requestFn) {
  this.get(route, (req, res) => 
      requestFn(req)
	    .run(GLOBALENV)
		.fork(error => res.status(error.code).send(error.message),
			  data => res.json(data)));
}

/* HERE IS OUR USER LEVEL CODE */

const fetchUser = id => ReaderTask(env => env.db.get(id));

app.getF('/user/:id', req => fetchUser(req.params.id));

app.listen(3000);