Gleam: To be used anonymously in same module, functions must be exported

Created on 22 Dec 2019 · 2Comments · Source: gleam-lang/gleam

If I define a function in a Gleam module, it can't be referred to without being invoked unless it is public. For example:

// hello_world.gleam
import gleam/string

fn hello(to whom: String) -> String {
  string.append(to: "Hello ", suffix: whom)
}

pub fn hello_world() -> String {
  let greeting = hello

  greeting("world")
}

generates the following Erlang code:

-module(hello_world).
-compile(no_auto_import).

-export([hello_world/0]).

hello(Whom) ->
    gleam@string:append(<<"Hello ">>, Whom).

hello_world() ->
    Greeting = fun hello_world:hello/1,
    Greeting(<<"world">>).

This will produce a runtime error when executed because the hello/1 function is qualified by the current module name, which means that it needs to be exported. If I change it to fun hello/1, everything works as expected!

bug

Source