For the uninitiated... Erlang 19's included Dialyzer improves the scenario of type-checking maps in useful ways. Namely that now you can represent an empty ma

For the uninitiated... Erlang 19's included Dialyzer improves the scenario of type-checking maps in useful ways. Namely that now you can represent an empty map, an arbitrary map of any type, and a partially arbitrary map which must include certain key type and value type associations but is not limited to those. Which leaves out one representation which is a map which includes and only includes a specific set of key type and value type associations. Erlang 18's Dialyzer has basically just #{} =:= map() which is equivalent to the union of #{none() => none()} and #{any() => any()}, so it was basically a giant escape hatch in the type-checking system, and thus not particularly valuable. Looking forward to a pending change in laxness as a result of the coming changes in 19. :-)