Use

Use allows you to bring names in modules into your current scope so they can be used without prefixing.

net::subscribe(...); // call subscribe in the net module
use net;
subscribe(...) // same function

Use is valid anywhere expressions are valid

let list = {
  use array;
  map([1, 2, 3, 4, 5], |x| x * 2)
};
list

will print [2, 4, 6, 8, 10]

let list = {
  use array;
  map([1, 2, 3, 4, 5], |x| x * 2)
};
map(list, |x| x * 2)

will not compile, e.g.

eric@katana ~> proj/graphix/target/debug/graphix ./test.gx
Error: in file "/home/eric/test.gx"

Caused by:
    at line: 5, column: 1 map not defined

Use shadows earlier declarations in it's scope. Consider,

let map = |a, f| "hello you called map!";
let list = {
  use array;
  map([1, 2, 3, 4, 5], |x| x * 2)
};
(list, map(list, |x| x * 2))

prints

eric@katana ~> proj/graphix/target/debug/graphix ./test.gx
([2, 4, 6, 8, 10], "hello you called map!")