src/doc/book/listings/ch13-functional-features/listing-13-03/src/main.rs

   1 use std::thread;
   2 use std::time::Duration;
   3
   4 fn simulated_expensive_calculation(intensity: u32) -> u32 {
   5     println!("calculating slowly...");
   6     thread::sleep(Duration::from_secs(2));
   7     intensity
   8 }
   9
  10 // ANCHOR: here
  11 fn generate_workout(intensity: u32, random_number: u32) {
  12     if intensity < 25 {
  13         println!(
  14             "Today, do {} pushups!",
  15             simulated_expensive_calculation(intensity)
  16         );
  17         println!(
  18             "Next, do {} situps!",
  19             simulated_expensive_calculation(intensity)
  20         );
  21     } else {
  22         if random_number == 3 {
  23             println!("Take a break today! Remember to stay hydrated!");
  24         } else {
  25             println!(
  26                 "Today, run for {} minutes!",
  27                 simulated_expensive_calculation(intensity)
  28             );
  29         }
  30     }
  31 }
  32 // ANCHOR_END: here
  33
  34 fn main() {
  35     let simulated_user_specified_value = 10;
  36     let simulated_random_number = 7;
  37
  38     generate_workout(simulated_user_specified_value, simulated_random_number);
  39 }