Cancel main without closing ghci

Question

I'm working on a web server using Scotty. I can run ghci and keep using :r to get it to reload my code, but if I even run main I cant' restart the web server without killing ghci.

How can I cancel main without closing ghci? Is there a better way to handle web servers and automatically restart them?

Answer 1

Invoke :set args <arg> ... in ghci to set the arguments that will be returned by System.getArgs.

Then, using the async package, launch the server in ghci with something like a <- async main.

Later invoke cancel a to kill the server.

See also this link that explains how to reload code even while the server is running.