Let the complete callback return the character to append to the selected
completion.
I didn't want to document this because it's specifically meant for
properties and unlikely to be needed by other scripts, but silently
interpreting the 3rd return value can screw you over if you do something
like
return candidates, code:find('[%w_]*$')
I was doing this in my lua-repl script, and find() returns the end
position as the 2rd argument, this becomes the 3rd return value and gets
appended to completions. So you have to do
return candidates, code:find('[%w_]*$'), nil
Needed to split running commands out of console.lua.