I have now released ~preview4 which resolves Issue #8 OCaml 4.07: the new Stdlib.Seq.t is functionally equivalent to Cf_seq.t. For OCaml 4.06, this introduces an external dependency on the seq compatibility package. I’ve also checked that documentary comments are available with odig, so this might be the last preview release before 1.0. (It depends on whether I decide to remove the support for the ppx_let syntax extension.)