Jozef Kosoru writes:
 > OK, and then I want to compile it (within a root directory):
 > 
 > 	$ ocamlc -c Kernel/Parser/pdf.ml
 > 	$ ocamlc -I . Kernel/Parser/pdf.cmo main.ml -o app
 > 
 > 	File "main.ml", line 1, characters 0-22:
 > 	Unbound value Kernel.Parser.Pdf.init
 > 
 > Is this supposed to work somehow?

No.

First, to compile  main.ml you need to pass  "-I Kernel/Parser" to the
compiler, because it needs to find the file pdf.cmi.

Second,  in   main.ml  you  have   to  write  "Pdf.init"   instead  of
"Kernel.Parser.Pdf.init" because the directory structure is not turned
into a module structure in ocaml.

However, you can use the option -pack and -for-pack of the compiler to
pack several  files as submodules of  a new module; see  the manual at
http://caml.inria.fr/pub/docs/manual-ocaml/manual025.html

-- 
Jean-Christophe