`module Pattern : sig ... end`
`val split_path : Ppxlib__.Import.string ‑> Ppxlib__.Import.string * Ppxlib__.Import.string Ppxlib__.Import.option`

Split the path part of a name:

`split_path "a.b.C.D" = "a.b", Some "C.D"`

`val dot_suffixes : Ppxlib__.Import.string ‑> Ppxlib__.Import.string Ppxlib__.Import.list`

`fold_dot_suffixes "foo.@bar.blah" ~init ~f` is

          ["bar.blah"; "foo.bar.blah"]

`module Registrar : sig ... end`
`module Whitelisted : sig ... end`
`module Reserved_namespaces : sig ... end`
`val comes_from_merlin : Ppxlib__.Import.string ‑> Ppxlib__.Import.bool`