1 files changed, 71 insertions, 0 deletions
diff --git a/src/components/servo/macros.rs b/src/components/servo/macros.rs
new file mode 100644
index 00000000000..8fe65bccfb6
--- /dev/null
+++ b/src/components/servo/macros.rs
@@ -0,0 +1,71 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+{
+    macro_rules! move_ref(
+        { $x:expr } => { unsafe { let y <- *ptr::to_unsafe_ptr(*$x); y } }
+    )
+
+    macro_rules! move_val(
+        { $x:expr } => { unsafe { let y <- *ptr::to_unsafe_ptr(*$x); y } }
+    )
+
+    // select!
+    macro_rules! select_if(
+    
+        {
+            $index:expr,
+            $count:expr
+        } => {
+            fail
+        };
+    
+        {
+            $index:expr,
+            $count:expr,
+            $port:path => [
+                $(type_this $message:path$(($(x $x: ident),+))dont_type_this*
+                  -> $next:ident => { $e:expr }),+
+            ]
+            $(, $ports:path => [
+                $(type_this $messages:path$(($(x $xs: ident),+))dont_type_this*
+                  -> $nexts:ident => { $es:expr }),+
+            ] )*
+        } => {
+            if $index == $count {
+                match pipes::try_recv($port) {
+                  $(Some($message($($(ref $x,)+)* ref next)) => {
+                    // FIXME (#2329) we really want move out of enum here.
+                    let $next = move_ref!(next);
+                    $e
+                  })+
+                  _ => fail
+                }
+            } else {
+                select_if!(
+                    $index,
+                    $count + 1
+                    $(, $ports => [
+                        $(type_this $messages$(($(x $xs),+))dont_type_this*
+                          -> $nexts => { $es }),+
+                    ])*
+                )
+            }
+        };
+    )
+    
+    macro_rules! select(
+        {
+            $( $port:path => {
+                $($message:path$(($($x: ident),+))dont_type_this*
+                  -> $next:ident $e:expr),+
+            } )+
+        } => {
+            let index = pipes::selecti([$(($port).header()),+]/_);
+            select_if!(index, 0 $(, $port => [
+                $(type_this $message$(($(x $x),+))dont_type_this* -> $next => { $e }),+
+            ])+)
+        }
+    )
+}