The Atom editor has great support for Idris. When I tried to get into it, I happened upon a rather nasty longstanding bug that made it impossible for me to use it, I couldn’t type backslash on a Swedish keyboard. Atom defines loads of Ctrl-Alt keybindings that overloads the AltGr bindings commonly found on European keyboards.

To fix it I did the following:

• I toggled the keybinding resolver (in the packages menu) to see exactly what the keybinding is named and what it’s triggering.
• I found that the keybinding was ctrl-alt-= and that it resized a pane, hardly an essential thing so I didn’t need to allocate a new binding for it.
• I added the following to the user bindings file (choose ‘Open yor keymap’ in the files menu) to make it use the native keybinding for that combo:

    'atom-text-editor':
        'ctrl-alt-=': 'native!'