Am Donnerstag, den 09.04.2015, 17:33 +0200 schrieb Daniel Bünzli:
> In the assemblage project we are quite interested in seeing packages as named entities providing flags/and or objects to use in a given command execution context (defined as pre-processing, compiling, linking, etc. see [1] for more details).
> 
> During the first build ("configure") we want to `ocamlfind query` packages for the right flags in each context and cache them so that we don't have to go through ocamlfind during the compilation (which slows down things quite a bit). 
> 
> Is there an invocation that allow us to get the flags or objects to use, the following don't seem to work:
> 
> > ocamlfind query -predicates ppx -pp lwt.ppx
> > ocamlfind query -pp lwt.ppx 
> 
> 
> and I don't see an obvious specifier for `-format` I can use. 

ocamlfind query -format '%(ppx)' lwt.ppx

-pp is not meant for ppx.

> It would be nice in general if ocamlfind would allow us to use `ocamlfind query` in obvious ways so that we can exactly reproduce what it does when whatever `ocamlfind TOOL -pkg PKG1,PKG2,PKG3` is being invoked. 

E.g.

ocamlfind ocamlc -only-show ...

then get the command from stdout and run it as often as you want.

Gerd

> I'm not working on this at the moment and don't have these things in my head but I remember that it proved to be quite challenging (if not impossible) to achieve that goal. 
> 
> Best,
> 
> Daniel
> 
> [1] http://samoht.github.io/assemblage/Assemblage.Ctx.html
> 
> 
> 

-- 
------------------------------------------------------------
Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
My OCaml site:          http://www.camlcity.org
Contact details:        http://www.camlcity.org/contact.html
Company homepage:       http://www.gerd-stolpmann.de
------------------------------------------------------------