This page suggests by pressing Control + Space I should get a complete list of code completion options.
If I type a letter I do see the code completion options for that letter, but Control + Space on a Mac toggles the keyboard language. What am I doing wrong?
As you have Ctrl+space bound to input switching in OSX preferences, you have to re-bind either the OS shortcut or the IDE one to avoid conflicts; for example, you can assign Cmd+space to Main Menu | Code | Code Completion | Basic action in Preferences | Keymap and use Cmd+space to trigger code completion