Rustup (generator support)

tests/run-pass/generator_control_flow.rs

@@ -0,0 +1,65 @@
+// Copyright 2017 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(generators, generator_trait)]
+
+use std::ops::{GeneratorState, Generator};
+
+fn finish<T>(mut amt: usize, mut t: T) -> T::Return
+    where T: Generator<Yield = ()>
+{
+    loop {
+        match t.resume() {
+            GeneratorState::Yielded(()) => amt -= 1,
+            GeneratorState::Complete(ret) => {
+                assert_eq!(amt, 0);
+                return ret
+            }
+        }
+    }
+
+}
+
+fn main() {
+    finish(1, || yield);
+    finish(3, || {
+        let mut x = 0;
+        yield;
+        x += 1;
+        yield;
+        x += 1;
+        yield;
+        assert_eq!(x, 2);
+    });
+    finish(8, || {
+        for _ in 0..8 {
+            yield;
+        }
+    });
+    finish(1, || {
+        if true {
+            yield;
+        } else {
+        }
+    });
+    finish(1, || {
+        if false {
+        } else {
+            yield;
+        }
+    });
+    finish(2, || {
+        if { yield; false } {
+            yield;
+            panic!()
+        }
+        yield
+    });
+}