src/test/run-pass/while-let.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use std::collections::BinaryHeap;
  12
  13 fn make_pq() -> BinaryHeap<int> {
  14     BinaryHeap::from_vec(vec![1i,2,3])
  15 }
  16
  17 pub fn main() {
  18     let mut pq = make_pq();
  19     let mut sum = 0i;
  20     while let Some(x) = pq.pop() {
  21         sum += x;
  22     }
  23     assert_eq!(sum, 6i);
  24
  25     pq = make_pq();
  26     sum = 0;
  27     'a: while let Some(x) = pq.pop() {
  28         sum += x;
  29         if x == 2 {
  30             break 'a;
  31         }
  32     }
  33     assert_eq!(sum, 5i);
  34
  35     pq = make_pq();
  36     sum = 0;
  37     'a: while let Some(x) = pq.pop() {
  38         if x == 3 {
  39             continue 'a;
  40         }
  41         sum += x;
  42     }
  43     assert_eq!(sum, 3i);
  44
  45     let mut pq1 = make_pq();
  46     sum = 0;
  47     while let Some(x) = pq1.pop() {
  48         let mut pq2 = make_pq();
  49         while let Some(y) = pq2.pop() {
  50             sum += x * y;
  51         }
  52     }
  53     assert_eq!(sum, 6i + 12 + 18);
  54 }