Add tests for while let

src/test/compile-fail/lint-unnecessary-parens.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![deny(unnecessary_parens)]
-#![feature(if_let)]
+#![feature(if_let,while_let)]
 
 #[deriving(Eq, PartialEq)]
 struct X { y: bool }
@@ -34,6 +34,7 @@ fn main() {
         _ => {}
     }
     if let 1i = (1i) {} //~ ERROR unnecessary parentheses around `if let` head expression
+    while let 1i = (2i) {} //~ ERROR unnecessary parentheses around `while let` head expression
     let v = X { y: false };
     // struct lits needs parens, so these shouldn't warn.
     if (v == X { y: true }) {}

src/test/compile-fail/while-let.rs

@@ -0,0 +1,37 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(macro_rules,while_let)]
+
+fn macros() {
+    macro_rules! foo{
+        ($p:pat, $e:expr, $b:block) => {{
+            while let $p = $e $b
+        }}
+    }
+    macro_rules! bar{
+        ($p:pat, $e:expr, $b:block) => {{
+            foo!($p, $e, $b)
+        }}
+    }
+
+    foo!(a, 1i, { //~ ERROR irrefutable while-let
+        println!("irrefutable pattern");
+    });
+    bar!(a, 1i, { //~ ERROR irrefutable while-let
+        println!("irrefutable pattern");
+    });
+}
+
+pub fn main() {
+    while let a = 1i { //~ ERROR irrefutable while-let
+        println!("irrefutable pattern");
+    }
+}

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

@@ -0,0 +1,56 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(while_let)]
+
+use std::collections::PriorityQueue;
+
+fn make_pq() -> PriorityQueue<int> {
+    PriorityQueue::from_vec(vec![1i,2,3])
+}
+
+pub fn main() {
+    let mut pq = make_pq();
+    let mut sum = 0i;
+    while let Some(x) = pq.pop() {
+        sum += x;
+    }
+    assert_eq!(sum, 6i);
+
+    pq = make_pq();
+    sum = 0;
+    'a: while let Some(x) = pq.pop() {
+        sum += x;
+        if x == 2 {
+            break 'a;
+        }
+    }
+    assert_eq!(sum, 5i);
+
+    pq = make_pq();
+    sum = 0;
+    'a: while let Some(x) = pq.pop() {
+        if x == 3 {
+            continue 'a;
+        }
+        sum += x;
+    }
+    assert_eq!(sum, 3i);
+
+    let mut pq1 = make_pq();
+    sum = 0;
+    while let Some(x) = pq1.pop() {
+        let mut pq2 = make_pq();
+        while let Some(y) = pq2.pop() {
+            sum += x * y;
+        }
+    }
+    assert_eq!(sum, 6i + 12 + 18);
+}