auto merge of #16664 : aturon/rust/stabilize-option-result, r=alexcrichton

Per API meeting

  https://github.com/rust-lang/meeting-minutes/blob/master/Meeting-API-review-2014-08-13.md

# Changes to `core::option`

Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.

However, a few methods have been deprecated, either due to lack of use or redundancy:

* `take_unwrap`, `get_ref` and `get_mut_ref` (redundant, and we prefer for this functionality to go through an explicit .unwrap)
* `filtered` and `while`
* `mutate` and `mutate_or_set`
* `collect`: this functionality is being moved to a new `FromIterator` impl.

# Changes to `core::result`

Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.

* `collect`: this functionality is being moved to a new `FromIterator` impl.
* `fold_` is deprecated due to lack of use
* Several methods found in `core::option` are added here, including `iter`, `as_slice`, and variants.

Due to deprecations, this is a:

[breaking-change]

Author: bors

src/compiletest/procsrv.rs

@@ -47,7 +47,7 @@ pub fn run(lib_path: &str,
     match cmd.spawn() {
         Ok(mut process) => {
             for input in input.iter() {
-                process.stdin.get_mut_ref().write(input.as_bytes()).unwrap();
+                process.stdin.as_mut().unwrap().write(input.as_bytes()).unwrap();
             }
             let ProcessOutput { status, output, error } =
                 process.wait_with_output().unwrap();
@@ -79,7 +79,7 @@ pub fn run_background(lib_path: &str,
     match cmd.spawn() {
         Ok(mut process) => {
             for input in input.iter() {
-                process.stdin.get_mut_ref().write(input.as_bytes()).unwrap();
+                process.stdin.as_mut().unwrap().write(input.as_bytes()).unwrap();
             }
 
             Some(process)

src/compiletest/runtest.rs

@@ -1526,7 +1526,7 @@ fn compile_cc_with_clang_and_save_bitcode(config: &Config, _props: &TestProps,
     let testcc = testfile.with_extension("cc");
     let proc_args = ProcArgs {
         // FIXME (#9639): This needs to handle non-utf8 paths
-        prog: config.clang_path.get_ref().as_str().unwrap().to_string(),
+        prog: config.clang_path.as_ref().unwrap().as_str().unwrap().to_string(),
         args: vec!("-c".to_string(),
                    "-emit-llvm".to_string(),
                    "-o".to_string(),
@@ -1542,7 +1542,7 @@ fn extract_function_from_bitcode(config: &Config, _props: &TestProps,
     let bitcodefile = output_base_name(config, testfile).with_extension("bc");
     let bitcodefile = append_suffix_to_stem(&bitcodefile, suffix);
     let extracted_bc = append_suffix_to_stem(&bitcodefile, "extract");
-    let prog = config.llvm_bin_path.get_ref().join("llvm-extract");
+    let prog = config.llvm_bin_path.as_ref().unwrap().join("llvm-extract");
     let proc_args = ProcArgs {
         // FIXME (#9639): This needs to handle non-utf8 paths
         prog: prog.as_str().unwrap().to_string(),
@@ -1559,7 +1559,7 @@ fn disassemble_extract(config: &Config, _props: &TestProps,
     let bitcodefile = append_suffix_to_stem(&bitcodefile, suffix);
     let extracted_bc = append_suffix_to_stem(&bitcodefile, "extract");
     let extracted_ll = extracted_bc.with_extension("ll");
-    let prog = config.llvm_bin_path.get_ref().join("llvm-dis");
+    let prog = config.llvm_bin_path.as_ref().unwrap().join("llvm-dis");
     let proc_args = ProcArgs {
         // FIXME (#9639): This needs to handle non-utf8 paths
         prog: prog.as_str().unwrap().to_string(),

src/libarena/lib.rs

@@ -476,7 +476,7 @@ impl<T> TypedArena<T> {
     /// Grows the arena.
     #[inline(never)]
     fn grow(&self) {
-        let chunk = self.first.borrow_mut().take_unwrap();
+        let chunk = self.first.borrow_mut().take().unwrap();
         let new_capacity = chunk.capacity.checked_mul(&2).unwrap();
         let chunk = TypedArenaChunk::<T>::new(Some(chunk), new_capacity);
         self.ptr.set(chunk.start() as *const T);
@@ -489,13 +489,13 @@ impl<T> TypedArena<T> {
 impl<T> Drop for TypedArena<T> {
     fn drop(&mut self) {
         // Determine how much was filled.
-        let start = self.first.borrow().get_ref().start() as uint;
+        let start = self.first.borrow().as_ref().unwrap().start() as uint;
         let end = self.ptr.get() as uint;
         let diff = (end - start) / mem::size_of::<T>();
 
         // Pass that to the `destroy` method.
         unsafe {
-            self.first.borrow_mut().get_mut_ref().destroy(diff)
+            self.first.borrow_mut().as_mut().unwrap().destroy(diff)
         }
     }
 }

src/libcollections/dlist.rs

@@ -649,7 +649,7 @@ impl<'a, A> MutItems<'a, A> {
                     None => return self.list.push_front_node(ins_node),
                     Some(prev) => prev,
                 };
-                let node_own = prev_node.next.take_unwrap();
+                let node_own = prev_node.next.take().unwrap();
                 ins_node.next = link_with_prev(node_own, Rawlink::some(&mut *ins_node));
                 prev_node.next = link_with_prev(ins_node, Rawlink::some(prev_node));
                 self.list.length += 1;

src/libcollections/ringbuf.rs

@@ -319,7 +319,7 @@ impl<'a, T> Iterator<&'a T> for Items<'a, T> {
         }
         let raw_index = raw_index(self.lo, self.elts.len(), self.index);
         self.index += 1;
-        Some(self.elts[raw_index].get_ref())
+        Some(self.elts[raw_index].as_ref().unwrap())
     }
 
     #[inline]
@@ -337,7 +337,7 @@ impl<'a, T> DoubleEndedIterator<&'a T> for Items<'a, T> {
         }
         self.rindex -= 1;
         let raw_index = raw_index(self.lo, self.elts.len(), self.rindex);
-        Some(self.elts[raw_index].get_ref())
+        Some(self.elts[raw_index].as_ref().unwrap())
     }
 }
 
@@ -353,7 +353,7 @@ impl<'a, T> RandomAccessIterator<&'a T> for Items<'a, T> {
             None
         } else {
             let raw_index = raw_index(self.lo, self.elts.len(), self.index + j);
-            Some(self.elts[raw_index].get_ref())
+            Some(self.elts[raw_index].as_ref().unwrap())
         }
     }
 }

src/libcollections/treemap.rs

@@ -1545,7 +1545,7 @@ impl<K: Ord, V> TreeNode<K, V> {
 // Remove left horizontal link by rotating right
 fn skew<K: Ord, V>(node: &mut Box<TreeNode<K, V>>) {
     if node.left.as_ref().map_or(false, |x| x.level == node.level) {
-        let mut save = node.left.take_unwrap();
+        let mut save = node.left.take().unwrap();
         swap(&mut node.left, &mut save.right); // save.right now None
         swap(node, &mut save);
         node.right = Some(save);
@@ -1557,7 +1557,7 @@ fn skew<K: Ord, V>(node: &mut Box<TreeNode<K, V>>) {
 fn split<K: Ord, V>(node: &mut Box<TreeNode<K, V>>) {
     if node.right.as_ref().map_or(false,
       |x| x.right.as_ref().map_or(false, |y| y.level == node.level)) {
-        let mut save = node.right.take_unwrap();
+        let mut save = node.right.take().unwrap();
         swap(&mut node.right, &mut save.left); // save.left now None
         save.level += 1;
         swap(node, &mut save);
@@ -1661,7 +1661,7 @@ fn remove<K: Ord, V>(node: &mut Option<Box<TreeNode<K, V>>>,
           Equal => {
             if save.left.is_some() {
                 if save.right.is_some() {
-                    let mut left = save.left.take_unwrap();
+                    let mut left = save.left.take().unwrap();
                     if left.right.is_some() {
                         heir_swap(save, &mut left.right);
                     } else {
@@ -1671,13 +1671,13 @@ fn remove<K: Ord, V>(node: &mut Option<Box<TreeNode<K, V>>>,
                     save.left = Some(left);
                     (remove(&mut save.left, key), true)
                 } else {
-                    let new = save.left.take_unwrap();
+                    let new = save.left.take().unwrap();
                     let box TreeNode{value, ..} = replace(save, new);
-                    *save = save.left.take_unwrap();
+                    *save = save.left.take().unwrap();
                     (Some(value), true)
                 }
             } else if save.right.is_some() {
-                let new = save.right.take_unwrap();
+                let new = save.right.take().unwrap();
                 let box TreeNode{value, ..} = replace(save, new);
                 (Some(value), true)
             } else {

src/libcore/cell.rs

@@ -99,7 +99,7 @@
 //!             // Take a reference to the inside of cache cell
 //!             let mut cache = self.span_tree_cache.borrow_mut();
 //!             if cache.is_some() {
-//!                 return cache.get_ref().clone();
+//!                 return cache.as_ref().unwrap().clone();
 //!             }
 //!
 //!             let span_tree = self.calc_span_tree();

src/libcore/iter.rs

@@ -2199,7 +2199,12 @@ pub fn iterate<'a, T: Clone>(f: |T|: 'a -> T, seed: T) -> Iterate<'a, T> {
         if *first {
             *first = false;
         } else {
-            val.mutate(|x| (*f)(x));
+            match val.take() {
+                Some(x) => {
+                    *val = Some((*f)(x))
+                }
+                None => {}
+            }
         }
         val.clone()
     })