De-mode task.rs and add some option::foo_ref() helpers

src/libcore/option.rs

@@ -46,7 +46,13 @@ pure fn map<T, U>(opt: option<T>, f: fn(T) -> U) -> option<U> {
     match opt { some(x) => some(f(x)), none => none }
 }
 
-pure fn map_consume<T, U>(-opt: option<T>, f: fn(-T) -> U) -> option<U> {
+pure fn map_ref<T, U>(opt: &option<T>, f: fn(x: &T) -> U) -> option<U> {
+    //! Maps a `some` value by reference from one type to another
+
+    match *opt { some(ref x) => some(f(x)), none => none }
+}
+
+pure fn map_consume<T, U>(+opt: option<T>, f: fn(+T) -> U) -> option<U> {
     /*!
      * As `map`, but consumes the option and gives `f` ownership to avoid
      * copying.
@@ -63,6 +69,16 @@ pure fn chain<T, U>(opt: option<T>, f: fn(T) -> option<U>) -> option<U> {
     match opt { some(x) => f(x), none => none }
 }
 
+pure fn chain_ref<T, U>(opt: &option<T>,
+                        f: fn(x: &T) -> option<U>) -> option<U> {
+    /*!
+     * Update an optional value by optionally running its content by reference
+     * through a function that returns an option.
+     */
+
+    match *opt { some(ref x) => f(x), none => none }
+}
+
 #[inline(always)]
 pure fn while_some<T>(+x: option<T>, blk: fn(+T) -> option<T>) {
     //! Applies a function zero or more times until the result is none.
@@ -97,14 +113,28 @@ pure fn map_default<T, U>(opt: option<T>, +def: U, f: fn(T) -> U) -> U {
     match opt { none => def, some(t) => f(t) }
 }
 
+// This should replace map_default.
+pure fn map_default_ref<T, U>(opt: &option<T>, +def: U,
+                              f: fn(x: &T) -> U) -> U {
+    //! Applies a function to the contained value or returns a default
+
+    match *opt { none => def, some(ref t) => f(t) }
+}
+
+// This should change to by-copy mode; use iter_ref below for by reference
 pure fn iter<T>(opt: option<T>, f: fn(T)) {
     //! Performs an operation on the contained value or does nothing
 
     match opt { none => (), some(t) => f(t) }
 }
 
+pure fn iter_ref<T>(opt: &option<T>, f: fn(x: &T)) {
+    //! Performs an operation on the contained value by reference
+    match *opt { none => (), some(ref t) => f(t) }
+}
+
 #[inline(always)]
-pure fn unwrap<T>(-opt: option<T>) -> T {
+pure fn unwrap<T>(+opt: option<T>) -> T {
     /*!
      * Moves a value out of an option type and returns it.
      *
@@ -130,12 +160,13 @@ fn swap_unwrap<T>(opt: &mut option<T>) -> T {
     unwrap(util::replace(opt, none))
 }
 
-pure fn unwrap_expect<T>(-opt: option<T>, reason: &str) -> T {
+pure fn unwrap_expect<T>(+opt: option<T>, reason: &str) -> T {
     //! As unwrap, but with a specified failure message.
     if opt.is_none() { fail reason.to_unique(); }
     unwrap(opt)
 }
 
+// Some of these should change to be &option<T>, some should not. See below.
 impl<T> option<T> {
     /**
      * Update an optional value by optionally running its content through a
@@ -155,6 +186,23 @@ impl<T> option<T> {
     pure fn map<U>(f: fn(T) -> U) -> option<U> { map(self, f) }
 }
 
+impl<T> &option<T> {
+    /**
+     * Update an optional value by optionally running its content by reference
+     * through a function that returns an option.
+     */
+    pure fn chain_ref<U>(f: fn(x: &T) -> option<U>) -> option<U> {
+        chain_ref(self, f)
+    }
+    /// Applies a function to the contained value or returns a default
+    pure fn map_default_ref<U>(+def: U, f: fn(x: &T) -> U) -> U
+        { map_default_ref(self, def, f) }
+    /// Performs an operation on the contained value by reference
+    pure fn iter_ref(f: fn(x: &T)) { iter_ref(self, f) }
+    /// Maps a `some` value from one type to another by reference
+    pure fn map_ref<U>(f: fn(x: &T) -> U) -> option<U> { map_ref(self, f) }
+}
+
 impl<T: copy> option<T> {
     /**
      * Gets the value out of an option

src/libcore/send_map.rs

@@ -237,11 +237,11 @@ mod linear {
     }
 
     impl<K,V> &const linear_map<K,V> {
-        fn len() -> uint {
+        pure fn len() -> uint {
             self.size
         }
 
-        fn is_empty() -> bool {
+        pure fn is_empty() -> bool {
             self.len() == 0
         }
 

src/libcore/task.rs

@@ -1,3 +1,7 @@
+// NB: transitionary, de-mode-ing.
+#[forbid(deprecated_mode)];
+#[forbid(deprecated_pattern)];
+
 /*!
  * Task management.
  *
@@ -730,8 +734,8 @@ type taskgroup_arc = unsafe::Exclusive<option<taskgroup_data>>;
 type taskgroup_inner = &mut option<taskgroup_data>;
 
 // A taskgroup is 'dead' when nothing can cause it to fail; only members can.
-fn taskgroup_is_dead(tg: taskgroup_data) -> bool {
-    (&mut tg.members).is_empty()
+pure fn taskgroup_is_dead(tg: &taskgroup_data) -> bool {
+    (&tg.members).is_empty()
 }
 
 // A list-like structure by which taskgroups keep track of all ancestor groups
@@ -841,8 +845,11 @@ fn each_ancestor(list:        &mut ancestor_list,
                     do with_parent_tg(&mut nobe.parent_group) |tg_opt| {
                         // Decide whether this group is dead. Note that the
                         // group being *dead* is disjoint from it *failing*.
-                        do tg_opt.iter |tg| {
-                            nobe_is_dead = taskgroup_is_dead(tg);
+                        match *tg_opt {
+                            some(ref tg) => {
+                                nobe_is_dead = taskgroup_is_dead(tg);
+                            },
+                            none => { }
                         }
                         // Call iterator block. (If the group is dead, it's
                         // safe to skip it. This will leave our *rust_task
@@ -1100,7 +1107,7 @@ fn gen_child_taskgroup(linked: bool, supervised: bool)
     }
 }
 
-fn spawn_raw(opts: task_opts, +f: fn~()) {
+fn spawn_raw(+opts: task_opts, +f: fn~()) {
     let (child_tg, ancestors, is_main) =
         gen_child_taskgroup(opts.linked, opts.supervised);
 
@@ -1138,10 +1145,10 @@ fn spawn_raw(opts: task_opts, +f: fn~()) {
     // (3a) If any of those fails, it leaves all groups, and does nothing.
     // (3b) Otherwise it builds a task control structure and puts it in TLS,
     // (4) ...and runs the provided body function.
-    fn make_child_wrapper(child: *rust_task, -child_arc: taskgroup_arc,
-                          -ancestors: ancestor_list, is_main: bool,
+    fn make_child_wrapper(child: *rust_task, +child_arc: taskgroup_arc,
+                          +ancestors: ancestor_list, is_main: bool,
                           notify_chan: option<comm::chan<notification>>,
-                          -f: fn~()) -> fn~() {
+                          +f: fn~()) -> fn~() {
         let child_data = ~mut some((child_arc, ancestors));
         return fn~() {
             // Agh. Get move-mode items into the closure. FIXME (#2829)