A simple test for the elm-lang/keyboard package.
To run it:
cd .../elm-keyboard-example
elm reactor
Then aim your browser at localhost:8000/keyboard-test.elm, and press keys on your keyboard to see them displayed on the page, and their keycodes displayed in your browser's developer tools debugging console.
To include the elm-lang/keyboard package in your own project:
cd .../path/to/your/project/directory
elm package install elm-lang/keyboard
elm-lang/keyboard is documented here.
I built an HTML file with:
elm make keyboard-test.elm --output elm-keyboard-example.html
And uploaded that to lisplog.org/elm-keyboard-example.html.
The source code is at github.com/billstclair/elm-keyboard-example.
This example illustrates the problems documented at github.com/elm-lang/keyboard/issues/3: "Not all key codes work in every browser."