You can search for identifiers within the package.
in-package search v0.2.0
val any : Base.char t
val one_of : Base.char Base.list -> Base.char t
val not_one_of : Base.char Base.list -> Base.char t
val upper : Base.char t
val lower : Base.char t
val alpha : Base.char t
val digit : Base.char t
val alnum : Base.char t
val space : Base.char t