An unknown exception was thrown when the command was being run
The user wanted to exit the REPL
Failing results never call their callbacks, and just remain unchanged
A known failure occured, maybe caused by an exception (e.
Successes map and flatmap just like a simple Box[T]
Nothing was entered
Maps a Res-returning function across a collection M[T]
, failing fast and
bailing out if any individual element fails.