Use try syntax for Option where appropriate

components/bluetooth/lib.rs

@@ -321,10 +321,7 @@ impl BluetoothManager {
             self.adapter = BluetoothAdapter::init().ok();
         }
 
-        let adapter = match self.adapter.as_ref() {
+        let adapter = self.adapter.as_ref()?;
-            Some(adapter) => adapter,
-            None => return None,
-        };
 
         if is_mock_adapter(adapter) && !adapter.is_present().unwrap_or(false) {
             return None;
@@ -422,14 +419,8 @@ impl BluetoothManager {
     }
 
     fn device_from_service_id(&self, service_id: &str) -> Option<BluetoothDevice> {
-        let device_id = match self.service_to_device.get(service_id) {
+        let device_id = self.service_to_device.get(service_id)?;
-            Some(id) => id,
+        self.cached_devices.get(device_id).cloned()
-            None => return None,
-        };
-        match self.cached_devices.get(device_id) {
-            Some(d) => Some(d.clone()),
-            None => None,
-        }
     }
 
     fn device_is_cached(&self, device_id: &str) -> bool {
@@ -471,10 +462,7 @@ impl BluetoothManager {
 
     fn get_gatt_service(&mut self, adapter: &mut BluetoothAdapter, service_id: &str) -> Option<&BluetoothGATTService> {
         return_if_cached!(self.cached_services, service_id);
-        let device_id = match self.service_to_device.get(service_id) {
+        let device_id = self.service_to_device.get(service_id)?.clone();
-            Some(d) => d.clone(),
-            None => return None,
-        };
         self.get_and_cache_gatt_services(adapter, &device_id);
         return_if_cached!(self.cached_services, service_id);
         None
@@ -508,10 +496,7 @@ impl BluetoothManager {
                                characteristic_id: &str)
                                -> Option<&BluetoothGATTCharacteristic> {
         return_if_cached!(self.cached_characteristics, characteristic_id);
-        let service_id = match self.characteristic_to_service.get(characteristic_id) {
+        let service_id = self.characteristic_to_service.get(characteristic_id)?.clone();
-            Some(s) => s.clone(),
-            None => return None,
-        };
         self.get_and_cache_gatt_characteristics(adapter, &service_id);
         return_if_cached!(self.cached_characteristics, characteristic_id);
         None
@@ -566,10 +551,7 @@ impl BluetoothManager {
                            descriptor_id: &str)
                            -> Option<&BluetoothGATTDescriptor> {
         return_if_cached!(self.cached_descriptors, descriptor_id);
-        let characteristic_id = match self.descriptor_to_characteristic.get(descriptor_id) {
+        let characteristic_id = self.descriptor_to_characteristic.get(descriptor_id)?.clone();
-            Some(c) => c.clone(),
-            None => return None,
-        };
         self.get_and_cache_gatt_descriptors(adapter, &characteristic_id);
         return_if_cached!(self.cached_descriptors, descriptor_id);
         None

components/devtools/lib.rs

@@ -317,16 +317,10 @@ fn run_server(sender: Sender<DevtoolsControlMsg>,
                           actor_pipelines: &HashMap<PipelineId, String>) -> Option<String> {
         let actors = actors.lock().unwrap();
         if let Some(worker_id) = worker_id {
-            let actor_name = match (*actor_workers).get(&(id, worker_id)) {
+            let actor_name = (*actor_workers).get(&(id, worker_id))?;
-                Some(name) => name,
-                None => return None,
-            };
             Some(actors.find::<WorkerActor>(actor_name).console.clone())
         } else {
-            let actor_name = match (*actor_pipelines).get(&id) {
+            let actor_name = (*actor_pipelines).get(&id)?;
-                Some(name) => name,
-                None => return None,
-            };
             Some(actors.find::<TabActor>(actor_name).console.clone())
         }
     }

components/layout/fragment.rs

@@ -2895,10 +2895,7 @@ impl Fragment {
     /// Returns the 4D matrix representing this fragment's transform.
     pub fn transform_matrix(&self, stacking_relative_border_box: &Rect<Au>) -> Option<Transform3D<f32>> {
         let list = &self.style.get_box().transform;
-        let transform = match list.to_transform_3d_matrix(Some(stacking_relative_border_box)) {
+        let transform = list.to_transform_3d_matrix(Some(stacking_relative_border_box))?;
-            Some(transform) => transform,
-            None => return None,
-        };
 
         let transform_origin = &self.style.get_box().transform_origin;
         let transform_origin_x =
@@ -3039,10 +3036,7 @@ impl<'a> Iterator for InlineStyleIterator<'a> {
             self.primary_style_yielded = true;
             return Some(&*self.fragment.style)
         }
-        let inline_context = match self.fragment.inline_context {
+        let inline_context = self.fragment.inline_context.as_ref()?;
-            None => return None,
-            Some(ref inline_context) => inline_context,
-        };
         let inline_style_index = self.inline_style_index;
         if inline_style_index == inline_context.nodes.len() {
             return None

components/layout/inline.rs

@@ -384,10 +384,7 @@ impl LineBreaker {
                                  -> Option<Fragment>
         where I: Iterator<Item=Fragment>,
     {
-        let mut result = match self.next_fragment(old_fragment_iter) {
+        let mut result = self.next_fragment(old_fragment_iter)?;
-            None => return None,
-            Some(fragment) => fragment,
-        };
 
         loop {
             let candidate = match self.next_fragment(old_fragment_iter) {

components/layout/persistent_list.rs

@@ -78,10 +78,7 @@ impl<'a, T> Iterator for PersistentListIterator<'a, T> where T: Send + Sync + 's
 
     #[inline]
     fn next(&mut self) -> Option<&'a T> {
-        let entry = match self.entry {
+        let entry = self.entry?;
-            None => return None,
-            Some(entry) => entry,
-        };
         let value = &entry.value;
         self.entry = match entry.next {
             None => None,

components/layout_thread/lib.rs

@@ -895,11 +895,7 @@ impl LayoutThread {
     }
 
     fn try_get_layout_root<N: LayoutNode>(&self, node: N) -> Option<FlowRef> {
-        let mut data = match node.mutate_layout_data() {
+        let result = node.mutate_layout_data()?.flow_construction_result.get();
-            Some(x) => x,
-            None => return None,
-        };
-        let result = data.flow_construction_result.get();
 
         let mut flow = match result {
             ConstructionResult::Flow(mut flow, abs_descendants) => {

components/net/hosts.rs

@@ -16,22 +16,13 @@ lazy_static! {
 }
 
 fn create_host_table() -> Option<HashMap<String, IpAddr>> {
-    // TODO: handle bad file path
+    let path = env::var_os("HOST_FILE")?;
-    let path = match env::var("HOST_FILE") {
-        Ok(host_file_path) => host_file_path,
-        Err(_) => return None,
-    };
 
-    let mut file = match File::open(&path) {
+    let file = File::open(&path).ok()?;
-        Ok(f) => BufReader::new(f),
+    let mut reader = BufReader::new(file);
-        Err(_) => return None,
-    };
 
     let mut lines = String::new();
-    match file.read_to_string(&mut lines) {
+    reader.read_to_string(&mut lines).ok()?;
-        Ok(_) => (),
-        Err(_) => return None,
-    };
 
     Some(parse_hostsfile(&lines))
 }

components/net/http_loader.rs

@@ -108,10 +108,7 @@ impl WrappedHttpResponse {
     }
 
     fn content_encoding(&self) -> Option<Encoding> {
-        let encodings = match self.headers().get::<ContentEncoding>() {
+        let &ContentEncoding(ref encodings) = self.headers().get()?;
-            Some(&ContentEncoding(ref encodings)) => encodings,
-            None => return None,
-        };
         if encodings.contains(&Encoding::Gzip) {
             Some(Encoding::Gzip)
         } else if encodings.contains(&Encoding::Deflate) {

components/profile/mem.rs

@@ -515,16 +515,11 @@ mod system_reporter {
         use std::fs::File;
         use std::io::Read;
 
-        // Like std::macros::try!, but for Option<>.
+        let mut f = File::open("/proc/self/statm").ok()?;
-        macro_rules! option_try(
-            ($e:expr) => (match $e { Some(e) => e, None => return None })
-        );
-
-        let mut f = option_try!(File::open("/proc/self/statm").ok());
         let mut contents = String::new();
-        option_try!(f.read_to_string(&mut contents).ok());
+        f.read_to_string(&mut contents).ok()?;
-        let s = option_try!(contents.split_whitespace().nth(field));
+        let s = contents.split_whitespace().nth(field)?;
-        let npages = option_try!(s.parse::<usize>().ok());
+        let npages = s.parse::<usize>().ok()?;
         Some(npages * page_size())
     }
 

components/script/dom/document.rs

@@ -2072,10 +2072,9 @@ fn get_registrable_domain_suffix_of_or_is_equal_to(host_suffix_string: &str, ori
         };
 
         // Step 4.2
-        let (prefix, suffix) = match original_host.len().checked_sub(host.len()) {
+        let index = original_host.len().checked_sub(host.len())?;
-            Some(index) => original_host.split_at(index),
+        let (prefix, suffix) = original_host.split_at(index);
-            None => return None,
+
-        };
         if !prefix.ends_with(".") {
             return None;
         }
@@ -2319,11 +2318,7 @@ impl Document {
     ///
     /// Also, shouldn't return an option, I'm quite sure.
     pub fn device(&self) -> Option<Device> {
-        let window_size = match self.window().window_size() {
+        let window_size = self.window().window_size()?;
-            Some(ws) => ws,
-            None => return None,
-        };
-
         let viewport_size = window_size.initial_viewport;
         let device_pixel_ratio = window_size.device_pixel_ratio;
         Some(Device::new(MediaType::screen(), viewport_size, device_pixel_ratio))
@@ -4017,12 +4012,9 @@ impl PendingInOrderScriptVec {
 
     fn take_next_ready_to_be_executed(&self) -> Option<(DomRoot<HTMLScriptElement>, ScriptResult)> {
         let mut scripts = self.scripts.borrow_mut();
-        let pair = scripts.front_mut().and_then(PendingScript::take_result);
+        let pair = scripts.front_mut()?.take_result()?;
-        if pair.is_none() {
-            return None;
-        }
         scripts.pop_front();
-        pair
+        Some(pair)
     }
 
     fn clear(&self) {

components/script/dom/element.rs

@@ -1039,24 +1039,20 @@ impl Element {
     // https://dom.spec.whatwg.org/#locate-a-namespace-prefix
     pub fn lookup_prefix(&self, namespace: Namespace) -> Option<DOMString> {
         for node in self.upcast::<Node>().inclusive_ancestors() {
-            match node.downcast::<Element>() {
+            let element = node.downcast::<Element>()?;
-                Some(element) => {
+            // Step 1.
-                    // Step 1.
+            if *element.namespace() == namespace {
-                    if *element.namespace() == namespace {
+                if let Some(prefix) = element.GetPrefix() {
-                        if let Some(prefix) = element.GetPrefix() {
+                    return Some(prefix);
-                            return Some(prefix);
+                }
-                        }
+            }
-                    }
 
-                    // Step 2.
+            // Step 2.
-                    for attr in element.attrs.borrow().iter() {
+            for attr in element.attrs.borrow().iter() {
-                        if attr.prefix() == Some(&namespace_prefix!("xmlns")) &&
+                if attr.prefix() == Some(&namespace_prefix!("xmlns")) &&
-                           **attr.value() == *namespace {
+                   **attr.value() == *namespace {
-                            return Some(attr.LocalName());
+                    return Some(attr.LocalName());
-                        }
+                }
-                    }
-                },
-                None => return None,
             }
         }
         None

components/script/dom/htmlcanvaselement.rs

@@ -219,12 +219,7 @@ impl HTMLCanvasElement {
                 let msg = CanvasMsg::FromScript(FromScriptMsg::SendPixels(sender));
                 context.get_ipc_renderer().send(msg).unwrap();
 
-                match receiver.recv().unwrap() {
+                receiver.recv().unwrap()?
-                    Some(pixels) => pixels,
-                    None => {
-                        return None;
-                    }
-                }
             },
             Some(&CanvasContext::WebGL(_)) => {
                 // TODO: add a method in WebGLRenderingContext to get the pixels.

components/script/dom/htmliframeelement.rs

@@ -588,17 +588,13 @@ impl HTMLIFrameElementMethods for HTMLIFrameElement {
     // https://html.spec.whatwg.org/multipage/#concept-bcc-content-document
     fn GetContentDocument(&self) -> Option<DomRoot<Document>> {
         // Step 1.
-        let pipeline_id = match self.pipeline_id.get() {
+        let pipeline_id = self.pipeline_id.get()?;
-            None => return None,
+
-            Some(pipeline_id) => pipeline_id,
-        };
         // Step 2-3.
         // Note that this lookup will fail if the document is dissimilar-origin,
         // so we should return None in that case.
-        let document = match ScriptThread::find_document(pipeline_id) {
+        let document = ScriptThread::find_document(pipeline_id)?;
-            None => return None,
+
-            Some(document) => document,
-        };
         // Step 4.
         let current = GlobalScope::current().expect("No current global object").as_window().Document();
         if !current.origin().same_origin_domain(document.origin()) {

components/script/dom/htmlimageelement.rs

@@ -661,10 +661,7 @@ impl HTMLImageElement {
     }
     pub fn areas(&self) -> Option<Vec<DomRoot<HTMLAreaElement>>> {
         let elem = self.upcast::<Element>();
-        let usemap_attr = match elem.get_attribute(&ns!(), &local_name!("usemap")) {
+        let usemap_attr = elem.get_attribute(&ns!(), &local_name!("usemap"))?;
-            Some(attr) => attr,
-            None => return None,
-        };
 
         let value = usemap_attr.value();
 

components/script/dom/node.rs

@@ -1206,11 +1206,7 @@ pub struct FollowingNodeIterator {
 impl FollowingNodeIterator {
     /// Skips iterating the children of the current node
     pub fn next_skipping_children(&mut self) -> Option<DomRoot<Node>> {
-        let current = match self.current.take() {
+        let current = self.current.take()?;
-            None => return None,
-            Some(current) => current,
-        };
-
         self.next_skipping_children_impl(current)
     }
 
@@ -1244,10 +1240,7 @@ impl Iterator for FollowingNodeIterator {
 
     // https://dom.spec.whatwg.org/#concept-tree-following
     fn next(&mut self) -> Option<DomRoot<Node>> {
-        let current = match self.current.take() {
+        let current = self.current.take()?;
-            None => return None,
-            Some(current) => current,
-        };
 
         if let Some(first_child) = current.GetFirstChild() {
             self.current = Some(first_child);
@@ -1268,10 +1261,7 @@ impl Iterator for PrecedingNodeIterator {
 
     // https://dom.spec.whatwg.org/#concept-tree-preceding
     fn next(&mut self) -> Option<DomRoot<Node>> {
-        let current = match self.current.take() {
+        let current = self.current.take()?;
-            None => return None,
-            Some(current) => current,
-        };
 
         self.current = if self.root == current {
             None
@@ -1323,10 +1313,7 @@ impl TreeIterator {
     }
 
     pub fn next_skipping_children(&mut self) -> Option<DomRoot<Node>> {
-        let current = match self.current.take() {
+        let current = self.current.take()?;
-            None => return None,
-            Some(current) => current,
-        };
 
         self.next_skipping_children_impl(current)
     }
@@ -1353,10 +1340,7 @@ impl Iterator for TreeIterator {
 
     // https://dom.spec.whatwg.org/#concept-tree-order
     fn next(&mut self) -> Option<DomRoot<Node>> {
-        let current = match self.current.take() {
+        let current = self.current.take()?;
-            None => return None,
-            Some(current) => current,
-        };
         if let Some(first_child) = current.GetFirstChild() {
             self.current = Some(first_child);
             self.depth += 1;

components/script/dom/servoparser/mod.rs

@@ -480,10 +480,7 @@ impl<I> Iterator for FragmentParsingResult<I>
     type Item = DomRoot<Node>;
 
     fn next(&mut self) -> Option<DomRoot<Node>> {
-        let next = match self.inner.next() {
+        let next = self.inner.next()?;
-            Some(next) => next,
-            None => return None,
-        };
         next.remove_self();
         Some(next)
     }

components/script/dom/treewalker.rs

@@ -395,13 +395,9 @@ impl TreeWalker {
             None => {
                 let mut candidate = DomRoot::from_ref(node);
                 while !self.is_root_node(&candidate) && candidate.GetNextSibling().is_none() {
-                    match candidate.GetParentNode() {
+                    // This can return None if the user set the current node to somewhere
-                        None =>
+                    // outside of the tree rooted at the original root.
-                            // This can happen if the user set the current node to somewhere
+                    candidate = candidate.GetParentNode()?;
-                            // outside of the tree rooted at the original root.
-                            return None,
-                        Some(n) => candidate = n
-                    }
                 }
                 if self.is_root_node(&candidate) {
                     None

components/script/dom/window.rs

@@ -592,15 +592,11 @@ impl WindowMethods for Window {
     // https://html.spec.whatwg.org/multipage/#dom-frameelement
     fn GetFrameElement(&self) -> Option<DomRoot<Element>> {
         // Steps 1-3.
-        let window_proxy = match self.window_proxy.get() {
+        let window_proxy = self.window_proxy.get()?;
-            None => return None,
+
-            Some(window_proxy) => window_proxy,
-        };
         // Step 4-5.
-        let container = match window_proxy.frame_element() {
+        let container = window_proxy.frame_element()?;
-            None => return None,
+
-            Some(container) => container,
-        };
         // Step 6.
         let container_doc = document_from_node(container);
         let current_doc = GlobalScope::current().expect("No current global object").as_window().Document();
@@ -688,10 +684,8 @@ impl WindowMethods for Window {
     // https://html.spec.whatwg.org/multipage/#dom-parent
     fn GetParent(&self) -> Option<DomRoot<WindowProxy>> {
         // Steps 1-3.
-        let window_proxy = match self.undiscarded_window_proxy() {
+        let window_proxy = self.undiscarded_window_proxy()?;
-            Some(window_proxy) => window_proxy,
+
-            None => return None,
-        };
         // Step 4.
         if let Some(parent) = window_proxy.parent() {
             return Some(DomRoot::from_ref(parent));
@@ -703,10 +697,8 @@ impl WindowMethods for Window {
     // https://html.spec.whatwg.org/multipage/#dom-top
     fn GetTop(&self) -> Option<DomRoot<WindowProxy>> {
         // Steps 1-3.
-        let window_proxy = match self.undiscarded_window_proxy() {
+        let window_proxy = self.undiscarded_window_proxy()?;
-            Some(window_proxy) => window_proxy,
+
-            None => return None,
-        };
         // Steps 4-5.
         Some(DomRoot::from_ref(window_proxy.top()))
     }

components/script/script_thread.rs

@@ -1946,10 +1946,7 @@ impl ScriptThread {
                            pipeline_id: PipelineId)
                            -> Option<DomRoot<WindowProxy>>
     {
-        let browsing_context_id = match self.ask_constellation_for_browsing_context_id(pipeline_id) {
+        let browsing_context_id = self.ask_constellation_for_browsing_context_id(pipeline_id)?;
-            Some(browsing_context_id) => browsing_context_id,
-            None => return None,
-        };
         if let Some(window_proxy) = self.window_proxies.borrow().get(&browsing_context_id) {
             return Some(DomRoot::from_ref(window_proxy));
         }