CODEWITHSUNDEEP
ocamlocaml-core
Jay Lee
Jay Lee

Reputation: 1912

Confusing OCaml Base/Core library deprecation warnings

I've been trying Jane Street's Base / Core libraries for a few hours now, and I got very confused by depracation warnings.

With the following code:

open Base
(* open Core *)
open Stdio

let _ = printf "%d" (4 mod 3)

I get a deprecation warning:

Alert deprecated: Base.mod
[2016-09] this element comes from the stdlib distributed with OCaml.
Use (%), which has slightly different semantics, or Int.rem which is equivalent.

I get that I have to use % or Int.rem, but when I simply open Core, the warning disappears. The documentation doesn't seem to clarify much regarding these 'deprecations'.

Also, with the following code:

(* open Base *)
open Core
(* open Stdio *)

let _ = Out_channel.output_string stdout "Hello, OCaml"
let line = In_channel.input_line_exn stdin

I get

Alert deprecated: Core.stdin
[since 2016-04] Use [In_channel.stdin]

but surprisingly, no alert for stdout.

When I uncomment the (* open Stdio *) line, I no longer get warnings. I can guess that Stdio module is probably shadowing the stdin/stdout, but I thought open Core was enough for this as it depends on the Stdio module.

I used

ocamlfind ocamlopt -o output.out -linkpkg -package base,stdio -thread output.ml

and with -package base,stdio, respectively.

  1. Why am I not getting a deprecation warning for 'mod' when I use open Core, if it warned me if I used open Base?

  2. Why am I getting no alert for stdout?

2-1. Is it normal necessary to open Stdio as well when I open Core?

Upvotes: 3

Views: 658

Answers (0)

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