“Eval” a string in OCaml

Question

I\'m trying to \"eval\" a string representing an OCaml expression in OCaml. I\'m looking to do something equivalent to Python\'s eval.

So far I\'ve not been able to find

Answer 1

Here is how to do it, but I didn't tell you. (Also the Parsing module is about Parsing, not executing code)

#require "compiler-libs" (* Assuming you're using utop, if compiling then this is the package you need *)
let eval code =
  let as_buf = Lexing.from_string code in
  let parsed = !Toploop.parse_toplevel_phrase as_buf in
  ignore (Toploop.execute_phrase true Format.std_formatter parsed)

example:

eval "let () = print_endline \"hello\";;"

Notice the trailing ;; in the code sample.

To use ocamlbuild, you will need to use both compiler-libs and compiler-libs.toplevel.