map -package:containers -package:dlist -package:conduit -package:basement -package:invertible -package:integration -package:pipes -package:os-string -package:base-prelude -package:blaze-html -package:regex-tdfa package:hedgehog is:exact
Generates a map using a
Range to determine the length.
This may fail to generate anything if the keys produced by the
generator do not account for a large enough number of unique
items to satify the required map size.