Performs completions from the given line state.
The first String argument is the contents of the line to the left of the cursor,
The second String argument is the contents of the line to the right of the cursor.
The output String is the unused portion of the left half of the line, reversed.
|replacement :: String||Text to insert in line.
|display :: String||Text to display when listing
|isFinished :: Bool||Whether this word should be followed by a
space, end quote, etc.
|Disable completion altogether.
|Create a finished completion out of the given word.
|List all of the files or folders beginning with this path.
|Produced by Haddock version 2.4.2|