elm-spa-example | elm v0 | Single Page Application library

I think sometimes you just have to do what's right for you. I used the Cmd.map/Sub.map/Html.map approach for an application I wrote that had 3 "pages" - Initializing, Editing and Reporting.

I wanted to make each of these pages its own module as they were relatively complicated, each had a fair number of messages that are only relevant to each page, and it's easier to reason about each page independently in its own context.

The downside is that the compiler won't prevent you from receiving the wrong message for a given page, leading to a runtime error (e.g., if the application receives an Editing.Save when it is in the Reporting page, what is the correct behavior? For my specific implementation, I just log it to the console and move on - this was good enough for me (and it never happened anyway); Other options I've considered include displaying a nasty error page to indicate that something horrible has happened - a BSOD if you will; Or to simply reset/reinitialize the entire application).