mod and use

use lib_demo::greet imports only greet; the rest of the module does not pollute the scope.

// Feature: import a single name from the module
// Syntax: `use foo::name` — `name` becomes available without prefix
// When to use: you only need one function/constant from that module;
// avoids polluting the scope with everything.

mod lib_demo

// We only need `greet` here — we ignore the rest.
use lib_demo::greet

fn main() {
  greet("zolo")

  // expected: Hello, zolo!

  greet("world")
  // expected: Hello, world!
}

use foo::{a, b, c} is more readable than three separate use statements when the names come from the same module.

// Feature: import several names as a list
// Syntax: `use foo::{a, b, c}` — all become accessible without prefix
// When to use: you need multiple things from the same module, but
// not all of them; more readable than multiple `use foo::name`.

mod lib_demo

// Imports three names at once.
use lib_demo::{add, sub, greet}

fn main() {
  greet("operations")

  // expected: Hello, operations!

  print("10 + 3 = {add(10, 3)}")

  // expected: 10 + 3 = 13

  print("10 - 3 = {sub(10, 3)}")
  // expected: 10 - 3 = 7
}

mod lib_demo loads the file; use lib_demo::{greet, add, get_pi, VERSION} makes all four names available without a prefix.

// Feature: declare a module with `mod` and use it via qualified path
// Syntax: `mod foo` — registers `foo.zolo` as module `foo`
// `use foo` + `foo::name` — call with prefix
// When to use: most explicit form; good when you want to make
// clear which module each name comes from.

// Loads the lib_demo.zolo file as a module.
mod lib_demo

// SKIP: `use lib_demo` (whole-module qualified access) currently
// fails to load — the lowering treats it as `use lib_demo::lib_demo`
// and complains about a missing `''` module. Use destructured names
// (`use lib_demo::greet`) or a list import instead, and call them
// directly without the prefix.
use lib_demo::{greet, add, get_pi, VERSION}

fn main() {
  greet("zolo")

  // expected: Hello, zolo!

  let s = add(2, 3)
  print("sum = {s}")

  // expected: sum = 5

  print("pi = {get_pi()}")

  // expected: pi = 3.14159

  print("version = {VERSION}")
  // expected: version = 1.0.0
}