[[!comment format=mdwn
 username="joey"
 subject="""comment 1"""
 date="2020-12-09T16:40:24Z"
 content="""
Indeed, and thank you for the patch.

However, MonadFail often suggests a code smell, here it's the `Just ... <-`
pattern match which could potentially fail. In fact, it's not possible for
it to, so I have instead made that clear in a way that the type checker
can understand.
"""]]
