src/content/chapter5_advanced_features/lesson01_use_sugar/code.gleam


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

import gleam/io
import gleam/result

pub fn main() {
  let x = {
    use username <- result.try(get_username())
    use password <- result.try(get_password())
    use greeting <- result.map(log_in(username, password))
    greeting <> ", " <> username
  }

  case x {
    Ok(greeting) -> io.println(greeting)
    Error(error) -> io.println("ERROR:" <> error)
  }
}

// Here are some pretend functions for this example:

fn get_username() {
  Ok("alice")
}

fn get_password() {
  Ok("hunter2")
}

fn log_in(_username: String, _password: String) {
  Ok("Welcome")
}