Here's an example I still don't know how to accomplish: module Map = struct module Make (Ord : BatInterfaces.OrderedType) : sig include module type of BatMap.Make(Ord).Labels (* this line is invalid *) end = struct include BatMap.Make(Ord) include Labels end end The idea is I only want "module type of Labels" for the functor's output, but I need BatMap.Make(Ord) within the implementation (perhaps to implement some other functions). I thought I can simply replace the line "include BatMap.Make(Ord)" with "open BatMap.Make(Ord)", and then not provide the explicit signature. But "open BatMap.Make(Ord)" gives a syntax error. 2012/2/22 Till Varoquaux > 2012/2/22 Milan Stanojević d > > On Tue, Feb 21, 2012 at 3:32 PM, Hezekiah M. Carty wrote: > >> On Tue, Feb 21, 2012 at 2:37 PM, Ashish Agarwal > wrote: > >>> I must've accidentally deleted part of my email before hitting send. > The > >>> point was to make the first code sample compile after removing the > commented > >>> line. But that is not allowed; I get a syntax error: > >>> > >>> $ ocamlfind ocamlc -c -package batteries a.ml > >>> File "a.ml", line 6, characters 38-39: > >>> Error: Syntax error: 'end' expected > >>> File "a.ml", line 4, characters 16-19: > >>> Error: This 'sig' might be unmatched > >>> > >>> I'm wondering if there is a better solution than my second code sample. > >>> > > > > I would consider this a bug. I think than any module expression than > > can be used with "include" should be usable with "include module type > > of" > > > > -- > > Caml-list mailing list. Subscription management and archives: > > https://sympa-roc.inria.fr/wws/info/caml-list > > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners > > Bug reports: http://caml.inria.fr/bin/caml-bugs > > > > Milan is right: the language grammar does say that both [include] and > [module type of] should work on module_expr. However, based upon the > manual(*), [A(B)] and [A.B] are syntacticly valid module_expr's but > [A(B).C] isn't. Is this because of an inherent limitation in the > module system? > > [*]http://caml.inria.fr/pub/docs/manual-ocaml/manual019.html#module-expr >