How to include other source files using the #use directive in OCaml?

Question

I'm a newbie with OCaml and I'd like to put some of the code into another file, say foo.ml, just as one would do in C++ or Python. But that part of code itself does not form a module.

I've included #use "foo.ml" in the head of my main source file. But when I build my project using ocamlbuild, it reports I/O error: "foo.ml: No such file or directory". But clearly foo.ml is in the current working directory.

I wonder if anyone knows how to achieve that aim in OCaml and let my project be built, or if that is not a convention in OCaml? Any suggestion is welcome.

Answer 1

#use "foo.ml" is a directive for the interactive toplevel, it doesn't work with the compiler.

If you want to split your code in different files (which is a good idea and is strongly recommended in OCaml), then you should use the module system. Why do you say your code doesn't form a module? If your code consists only of single-use functions, they should be in the same file as the functions that use them. If your code is reusable, then it forms a module.