Rethinking an http request in elm. This is an example app for a Front End Orlando talk on elm.
Start with the originalRequest branch, then maybeRefactor and finally unionTypesRefactor to see the progression.
This is how I originally began to write elm code. I set the repos model to an empty List Repo. It comes from working with react / redux. Have to set loading and request received flags to check what to display to the screen.
I changed the repos model to a Maybe (List Repo) in order to eliminate the request received flags. This made the view function more readable, but we were still checking for error messages and loading states.
This is the final version. I changed repos to take a union type of ExternalRequest error data with values of NotRequested | Loading | Failure error | Success data. I no longer had any flags to set and moved the errors into the ExternalRequest union type. The model shrank in half and the view function became a pattern matching case expression, making it much more readable.
