Expose (or un-expose) a function or type without scrolling around.
Put the cursor on the name of the function/type, press Option-Enter (macOS; Alt-Enter on Windows/Linux), and then select Add to exposing list (or, if it's already exposed, Remove from exposing list).
A special icon will be displayed next to exposed functions/types in the gutter next to the line number. Click the icon to jump to where it's exposed.
