Implement Index for HashMap

This also deprecates HashMap::get. Use indexing instead.

Author: ftxqxd

src/librustdoc/html/format.rs

@@ -166,7 +166,7 @@ fn resolved_path(w: &mut fmt::Formatter, did: ast::DefId, p: &clean::Path,
             if ast_util::is_local(did) || cache.inlined.contains(&did) {
                 Some(("../".repeat(loc.len())).to_string())
             } else {
-                match *cache.extern_locations.get(&did.krate) {
+                match cache.extern_locations[did.krate] {
                     render::Remote(ref s) => Some(s.to_string()),
                     render::Local => {
                         Some(("../".repeat(loc.len())).to_string())
@@ -291,11 +291,11 @@ fn primitive_link(f: &mut fmt::Formatter,
             needs_termination = true;
         }
         Some(&cnum) => {
-            let path = m.paths.get(&ast::DefId {
+            let path = &m.paths[ast::DefId {
                 krate: cnum,
                 node: ast::CRATE_NODE_ID,
-            });
-            let loc = match *m.extern_locations.get(&cnum) {
+            }];
+            let loc = match m.extern_locations[cnum] {
                 render::Remote(ref s) => Some(s.to_string()),
                 render::Local => {
                     let loc = current_location_key.get().unwrap();
@@ -343,11 +343,11 @@ impl fmt::Show for clean::Type {
         match *self {
             clean::TyParamBinder(id) => {
                 let m = cache_key.get().unwrap();
-                f.write(m.typarams.get(&ast_util::local_def(id)).as_bytes())
+                f.write(m.typarams[ast_util::local_def(id)].as_bytes())
             }
             clean::Generic(did) => {
                 let m = cache_key.get().unwrap();
-                f.write(m.typarams.get(&did).as_bytes())
+                f.write(m.typarams[did].as_bytes())
             }
             clean::ResolvedPath{ did, ref typarams, ref path } => {
                 try!(resolved_path(f, did, path, false));

src/librustdoc/html/render.rs

@@ -1252,8 +1252,8 @@ impl<'a> Item<'a> {
         // located, then we return `None`.
         } else {
             let cache = cache_key.get().unwrap();
-            let path = cache.external_paths.get(&self.item.def_id);
-            let root = match *cache.extern_locations.get(&self.item.def_id.krate) {
+            let path = &cache.external_paths[self.item.def_id];
+            let root = match cache.extern_locations[self.item.def_id.krate] {
                 Remote(ref s) => s.to_string(),
                 Local => self.cx.root_path.clone(),
                 Unknown => return None,

src/librustdoc/visit_ast.rs

@@ -229,7 +229,7 @@ impl<'a> RustdocVisitor<'a> {
             core::Typed(ref tcx) => tcx,
             core::NotTyped(_) => return false
         };
-        let def = tcx.def_map.borrow().get(&id).def_id();
+        let def = (*tcx.def_map.borrow())[id].def_id();
         if !ast_util::is_local(def) { return false }
         let analysis = match self.analysis {
             Some(analysis) => analysis, None => return false

src/libstd/collections/hashmap.rs

@@ -26,6 +26,7 @@ use mem::replace;
 use num;
 use option::{Some, None, Option};
 use result::{Ok, Err};
+use ops::Index;
 
 mod table {
     use clone::Clone;
@@ -1341,7 +1342,7 @@ impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
     ///
     /// // Update and return the existing value
     /// assert_eq!(*map.insert_or_update_with("a", 9, |_key, val| *val = 7), 7);
-    /// assert_eq!(map.get(&"a"), &7);
+    /// assert_eq!(map["a"], 7);
     /// ```
     pub fn insert_or_update_with<'a>(
                                  &'a mut self,
@@ -1392,9 +1393,9 @@ impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
     /// }
     ///
     /// assert_eq!(map.len(), 3);
-    /// assert_eq!(map.get(&"a key"), &vec!["value", "new value"]);
-    /// assert_eq!(map.get(&"b key"), &vec!["new value"]);
-    /// assert_eq!(map.get(&"z key"), &vec!["new value", "value"]);
+    /// assert_eq!(map["a key"], vec!["value", "new value"]);
+    /// assert_eq!(map["b key"], vec!["new value"]);
+    /// assert_eq!(map["z key"], vec!["new value", "value"]);
     /// ```
     pub fn find_with_or_insert_with<'a, A>(&'a mut self,
                                            k: K,
@@ -1426,12 +1427,15 @@ impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
     /// # Example
     ///
     /// ```
+    /// #![allow(deprecated)]
+    ///
     /// use std::collections::HashMap;
     ///
     /// let mut map = HashMap::new();
     /// map.insert("a", 1i);
     /// assert_eq!(map.get(&"a"), &1);
     /// ```
+    #[deprecated = "prefer indexing instead, e.g., map[key]"]
     pub fn get<'a>(&'a self, k: &K) -> &'a V {
         match self.find(k) {
             Some(v) => v,
@@ -1458,11 +1462,11 @@ impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
     ///     let val = map.get_mut(&"a");
     ///     *val = 40;
     /// }
-    /// assert_eq!(map.get(&"a"), &40);
+    /// assert_eq!(map["a"], 40);
     ///
     /// // A more direct way could be:
     /// *map.get_mut(&"a") = -2;
-    /// assert_eq!(map.get(&"a"), &-2);
+    /// assert_eq!(map["a"], -2);
     /// ```
     pub fn get_mut<'a>(&'a mut self, k: &K) -> &'a mut V {
         match self.find_mut(k) {
@@ -1738,6 +1742,21 @@ impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Default for HashMap<K, V, H>
     }
 }
 
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Index<K, V> for HashMap<K, V, H> {
+    #[inline]
+    fn index<'a>(&'a self, index: &K) -> &'a V {
+        self.get(index)
+    }
+}
+
+// FIXME(#12825) Indexing will always try IndexMut first and that causes issues.
+/*impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> ops::IndexMut<K, V> for HashMap<K, V, H> {
+    #[inline]
+    fn index_mut<'a>(&'a mut self, index: &K) -> &'a mut V {
+        self.get_mut(index)
+    }
+}*/
+
 /// HashMap iterator
 pub type Entries<'a, K, V> = table::Entries<'a, K, V>;
 
@@ -2694,6 +2713,29 @@ mod test_map {
 
         assert_eq!(iter.size_hint(), (3, Some(3)));
     }
+
+    #[test]
+    fn test_index() {
+        let mut map: HashMap<int, int> = HashMap::new();
+
+        map.insert(1, 2);
+        map.insert(2, 1);
+        map.insert(3, 4);
+
+        assert_eq!(map[2], 1);
+    }
+
+    #[test]
+    #[should_fail]
+    fn test_index_nonexistent() {
+        let mut map: HashMap<int, int> = HashMap::new();
+
+        map.insert(1, 2);
+        map.insert(2, 1);
+        map.insert(3, 4);
+
+        map[4];
+    }
 }
 
 #[cfg(test)]