This example illustrates a way to keep and modify server-side state accesible through a websocket client, with query logging.
The code features the use of monad transformers and lenses.
To run the example, build or just run it with Stack and open 127.0.0.1:8080 in a web-browser.
$ stack repl
ghci starts up
*Main AppState Cmd Host> main
starts server and prints logs