[BUG] Marshal.to_string 3.14 [] raises Failure

[kenichi-asai]

let str = Marshal.to_string 3. []
let len = String.length str
let _ = print_endline (string_of_int len)

The above program runs fine but replacing 3. with 3.14 produces 0,248,Failure,-3,output_value: abstract value (number) on Safari. Is this a bug?

ocamlc 4.04.0, js_of_ocaml 3.5.2, Safari 12.1.2 on macOS Sierra

[hhugo]

From the readme
marshalling of floats is not supported (unmarshalling works);

Jsoo is not able to differentiate between floats with no decimal part and integer, explaining why marshaling 3. doesn't raise (it would wrongly marshal it as int though)

[kenichi-asai]

Oh, I see. Thank you.

I wanted to send OCaml values containing floats via socket.io, and tried to convert them into strings using Marshal module. If I cannot use Marshal module, is there any other way to send OCaml values?

[dbuenzli]

Marshal module

Marshal is very unsafe, make sure you go over the details mentioned in this preamble. This makes it unsuitable to be used in a distributed setting where you don't tightly control producers and consumers. Hence, in particular, on the web.

There are various serialisation technologies available in OCaml I think best for you is to ask for advice on https://discuss.ocaml.org/

[kenichi-asai]

Thank you. Yes, I know Marshal is unsafe. I tried to use it because it is in the standard library and thus I can use it without any installation. (In my situation, I do have control over produces and consumers.) I will ask in the caml mailing list; I prefer not to create one more account.

[dbuenzli]

I prefer not to create one more account.

You can login with your github account.