Update reader/config.scala

[aaronlevin]

Just playing around. I don't quite understand how the for comprehension gets unwrapped so I created a trivial example that combines various ConfigReader functions and used only map and flatMap.

Mostly just an exercise.

An example of composing functions relying on various ConfigReader instances without using for comprehension.

[overthink]

Not unless a DBConnection implements map.

You can use plain "=" in a for comprehension though. e.g.

for {
  hello2String <- sayHello2
  dbHost <- dbHostReader
  dbConnection = new DBConnection(dbHost)
} yield (hello2String + getFromDb(dbConnection)