auto merge of #11686 : mankyKitty/rust/rename-invert-to-flip-issue-10632, r=alexcrichton

Renamed the ```invert()``` function in ```iter.rs``` to ```flip()```, from #10632 

Also renamed the ```Invert<T>``` type to ```Flip<T>```.

Some related code comments changed. Documentation that I could find has
been updated, and all the instances I could locate where the
function/type were called have been updated as well.

This is my first contribution to Rust! Apologies in advance if I've snarfed the 
PR process, I'm not used to rebase.

I initially had issues with the ```codegen``` section of the tests failing, however
the ```make check``` process is not reporting any failures at this time. I think
that was a local env issue more than me facerolling my changes. :)

Author: bors

doc/guide-container.md

@@ -336,8 +336,8 @@ The `DoubleEndedIterator` trait represents an iterator able to yield elements
 from either end of a range. It inherits from the `Iterator` trait and extends
 it with the `next_back` function.
 
-A `DoubleEndedIterator` can be flipped with the `invert` adaptor, returning
-another `DoubleEndedIterator` with `next` and `next_back` exchanged.
+A `DoubleEndedIterator` can have its direction changed with the `rev` adaptor,
+returning another `DoubleEndedIterator` with `next` and `next_back` exchanged.
 
 ~~~
 let xs = [1, 2, 3, 4, 5, 6];
@@ -347,7 +347,7 @@ println!("{:?}", it.next()); // prints `Some(&2)`
 println!("{:?}", it.next_back()); // prints `Some(&6)`
 
 // prints `5`, `4` and `3`
-for &x in it.invert() {
+for &x in it.rev() {
     println!("{}", x)
 }
 ~~~
@@ -366,7 +366,7 @@ let mut it = xs.iter().chain(ys.iter()).map(|&x| x * 2);
 println!("{:?}", it.next()); // prints `Some(2)`
 
 // prints `16`, `14`, `12`, `10`, `8`, `6`, `4`
-for x in it.invert() {
+for x in it.rev() {
     println!("{}", x);
 }
 ~~~

src/libextra/bitv.rs

@@ -13,7 +13,7 @@
 
 use std::cmp;
 use std::iter::RandomAccessIterator;
-use std::iter::{Invert, Enumerate, Repeat, Map, Zip};
+use std::iter::{Rev, Enumerate, Repeat, Map, Zip};
 use std::num;
 use std::ops;
 use std::uint;
@@ -387,7 +387,7 @@ impl Bitv {
         }
     }
 
-    /// Invert all bits
+    /// Flip all bits
     #[inline]
     pub fn negate(&mut self) {
         match self.rep {
@@ -428,8 +428,8 @@ impl Bitv {
     }
 
     #[inline]
-    pub fn rev_iter<'a>(&'a self) -> Invert<Bits<'a>> {
-        self.iter().invert()
+    pub fn rev_iter<'a>(&'a self) -> Rev<Bits<'a>> {
+        self.iter().rev()
     }
 
     /// Returns `true` if all bits are 0

src/libextra/dlist.rs

@@ -25,7 +25,7 @@
 use std::cast;
 use std::ptr;
 use std::util;
-use std::iter::Invert;
+use std::iter::Rev;
 use std::iter;
 
 use container::Deque;
@@ -368,8 +368,8 @@ impl<T> DList<T> {
 
     /// Provide a reverse iterator
     #[inline]
-    pub fn rev_iter<'a>(&'a self) -> Invert<Items<'a, T>> {
-        self.iter().invert()
+    pub fn rev_iter<'a>(&'a self) -> Rev<Items<'a, T>> {
+        self.iter().rev()
     }
 
     /// Provide a forward iterator with mutable references
@@ -388,8 +388,8 @@ impl<T> DList<T> {
     }
     /// Provide a reverse iterator with mutable references
     #[inline]
-    pub fn mut_rev_iter<'a>(&'a mut self) -> Invert<MutItems<'a, T>> {
-        self.mut_iter().invert()
+    pub fn mut_rev_iter<'a>(&'a mut self) -> Rev<MutItems<'a, T>> {
+        self.mut_iter().rev()
     }
 
 
@@ -401,8 +401,8 @@ impl<T> DList<T> {
 
     /// Consume the list into an iterator yielding elements by value, in reverse
     #[inline]
-    pub fn move_rev_iter(self) -> Invert<MoveItems<T>> {
-        self.move_iter().invert()
+    pub fn move_rev_iter(self) -> Rev<MoveItems<T>> {
+        self.move_iter().rev()
     }
 }
 

src/libextra/ringbuf.rs

@@ -15,7 +15,7 @@
 
 use std::num;
 use std::vec;
-use std::iter::{Invert, RandomAccessIterator};
+use std::iter::{Rev, RandomAccessIterator};
 
 use container::Deque;
 
@@ -192,8 +192,8 @@ impl<T> RingBuf<T> {
     }
 
     /// Back-to-front iterator.
-    pub fn rev_iter<'a>(&'a self) -> Invert<Items<'a, T>> {
-        self.iter().invert()
+    pub fn rev_iter<'a>(&'a self) -> Rev<Items<'a, T>> {
+        self.iter().rev()
     }
 
     /// Front-to-back iterator which returns mutable values.
@@ -223,8 +223,8 @@ impl<T> RingBuf<T> {
     }
 
     /// Back-to-front iterator which returns mutable values.
-    pub fn mut_rev_iter<'a>(&'a mut self) -> Invert<MutItems<'a, T>> {
-        self.mut_iter().invert()
+    pub fn mut_rev_iter<'a>(&'a mut self) -> Rev<MutItems<'a, T>> {
+        self.mut_iter().rev()
     }
 }
 

src/libextra/smallintmap.rs

@@ -15,7 +15,7 @@
 
 #[allow(missing_doc)];
 
-use std::iter::{Enumerate, FilterMap, Invert};
+use std::iter::{Enumerate, FilterMap, Rev};
 use std::util::replace;
 use std::vec;
 
@@ -140,14 +140,14 @@ impl<V> SmallIntMap<V> {
     /// An iterator visiting all key-value pairs in descending order by the keys.
     /// Iterator element type is (uint, &'r V)
     pub fn rev_iter<'r>(&'r self) -> RevEntries<'r, V> {
-        self.iter().invert()
+        self.iter().rev()
     }
 
     /// An iterator visiting all key-value pairs in descending order by the keys,
     /// with mutable references to the values
     /// Iterator element type is (uint, &'r mut V)
     pub fn mut_rev_iter<'r>(&'r mut self) -> RevMutEntries <'r, V> {
-        self.mut_iter().invert()
+        self.mut_iter().rev()
     }
 
     /// Empties the hash map, moving all values into the specified closure
@@ -241,7 +241,7 @@ pub struct Entries<'a, T> {
 
 iterator!(impl Entries -> (uint, &'a T), get_ref)
 double_ended_iterator!(impl Entries -> (uint, &'a T), get_ref)
-pub type RevEntries<'a, T> = Invert<Entries<'a, T>>;
+pub type RevEntries<'a, T> = Rev<Entries<'a, T>>;
 
 pub struct MutEntries<'a, T> {
     priv front: uint,
@@ -251,7 +251,7 @@ pub struct MutEntries<'a, T> {
 
 iterator!(impl MutEntries -> (uint, &'a mut T), get_mut_ref)
 double_ended_iterator!(impl MutEntries -> (uint, &'a mut T), get_mut_ref)
-pub type RevMutEntries<'a, T> = Invert<MutEntries<'a, T>>;
+pub type RevMutEntries<'a, T> = Rev<MutEntries<'a, T>>;
 
 #[cfg(test)]
 mod test_map {

src/libnative/io/process.rs

@@ -460,7 +460,7 @@ fn spawn_process_os(prog: &str, args: &[~str],
             fail!("failure in dup3(err_fd, 2): {}", os::last_os_error());
         }
         // close all other fds
-        for fd in range(3, getdtablesize()).invert() {
+        for fd in range(3, getdtablesize()).rev() {
             if fd != output.fd() {
                 close(fd as c_int);
             }

src/librustc/middle/trans/cleanup.rs

@@ -203,7 +203,7 @@ impl<'a> CleanupMethods<'a> for FunctionContext<'a> {
          */
 
         let scopes = self.scopes.borrow();
-        for scope in scopes.get().iter().invert() {
+        for scope in scopes.get().iter().rev() {
             match scope.kind {
                 LoopScopeKind(id, _) => {
                     return id;
@@ -325,7 +325,7 @@ impl<'a> CleanupMethods<'a> for FunctionContext<'a> {
                cleanup_scope);
 
         let mut scopes = self.scopes.borrow_mut();
-        for scope in scopes.get().mut_iter().invert() {
+        for scope in scopes.get().mut_iter().rev() {
             if scope.kind.is_ast_with_id(cleanup_scope) {
                 scope.cleanups.push(cleanup);
                 scope.clear_cached_exits();
@@ -368,7 +368,7 @@ impl<'a> CleanupMethods<'a> for FunctionContext<'a> {
          */
 
         let scopes = self.scopes.borrow();
-        scopes.get().iter().invert().any(|s| s.needs_invoke())
+        scopes.get().iter().rev().any(|s| s.needs_invoke())
     }
 
     fn get_landing_pad(&self) -> BasicBlockRef {
@@ -415,7 +415,7 @@ impl<'a> CleanupHelperMethods<'a> for FunctionContext<'a> {
          * Returns the id of the current top-most AST scope, if any.
          */
         let scopes = self.scopes.borrow();
-        for scope in scopes.get().iter().invert() {
+        for scope in scopes.get().iter().rev() {
             match scope.kind {
                 CustomScopeKind | LoopScopeKind(..) => {}
                 AstScopeKind(i) => {
@@ -428,7 +428,7 @@ impl<'a> CleanupHelperMethods<'a> for FunctionContext<'a> {
 
     fn top_nonempty_cleanup_scope(&self) -> Option<uint> {
         let scopes = self.scopes.borrow();
-        scopes.get().iter().invert().position(|s| !s.cleanups.is_empty())
+        scopes.get().iter().rev().position(|s| !s.cleanups.is_empty())
     }
 
     fn is_valid_to_pop_custom_scope(&self, custom_scope: CustomScopeIndex) -> bool {
@@ -450,7 +450,7 @@ impl<'a> CleanupHelperMethods<'a> for FunctionContext<'a> {
 
         let mut bcx = bcx;
         if !bcx.unreachable.get() {
-            for cleanup in scope.cleanups.iter().invert() {
+            for cleanup in scope.cleanups.iter().rev() {
                 bcx = cleanup.trans(bcx);
             }
         }
@@ -619,7 +619,7 @@ impl<'a> CleanupHelperMethods<'a> for FunctionContext<'a> {
                 debug!("generating cleanups for {}", name);
                 let bcx_in = self.new_block(label.is_unwind(), name, None);
                 let mut bcx_out = bcx_in;
-                for cleanup in scope.cleanups.iter().invert() {
+                for cleanup in scope.cleanups.iter().rev() {
                     if cleanup_is_suitable_for(*cleanup, label) {
                         bcx_out = cleanup.trans(bcx_out);
                     }

src/libstd/iter.rs

@@ -670,21 +670,21 @@ pub trait DoubleEndedIterator<A>: Iterator<A> {
     /// Yield an element from the end of the range, returning `None` if the range is empty.
     fn next_back(&mut self) -> Option<A>;
 
-    /// Flip the direction of the iterator
+    /// Change the direction of the iterator
     ///
-    /// The inverted iterator flips the ends on an iterator that can already
+    /// The flipped iterator swaps the ends on an iterator that can already
     /// be iterated from the front and from the back.
     ///
     ///
-    /// If the iterator also implements RandomAccessIterator, the inverted
+    /// If the iterator also implements RandomAccessIterator, the flipped
     /// iterator is also random access, with the indices starting at the back
     /// of the original iterator.
     ///
-    /// Note: Random access with inverted indices still only applies to the first
+    /// Note: Random access with flipped indices still only applies to the first
     /// `uint::max_value` elements of the original iterator.
     #[inline]
-    fn invert(self) -> Invert<Self> {
-        Invert{iter: self}
+    fn rev(self) -> Rev<Self> {
+        Rev{iter: self}
     }
 }
 
@@ -759,30 +759,30 @@ pub trait ExactSize<A> : DoubleEndedIterator<A> {
 // Adaptors that may overflow in `size_hint` are not, i.e. `Chain`.
 impl<A, T: ExactSize<A>> ExactSize<(uint, A)> for Enumerate<T> {}
 impl<'a, A, T: ExactSize<A>> ExactSize<A> for Inspect<'a, A, T> {}
-impl<A, T: ExactSize<A>> ExactSize<A> for Invert<T> {}
+impl<A, T: ExactSize<A>> ExactSize<A> for Rev<T> {}
 impl<'a, A, B, T: ExactSize<A>> ExactSize<B> for Map<'a, A, B, T> {}
 impl<A, B, T: ExactSize<A>, U: ExactSize<B>> ExactSize<(A, B)> for Zip<T, U> {}
 
 /// An double-ended iterator with the direction inverted
 #[deriving(Clone)]
-pub struct Invert<T> {
+pub struct Rev<T> {
     priv iter: T
 }
 
-impl<A, T: DoubleEndedIterator<A>> Iterator<A> for Invert<T> {
+impl<A, T: DoubleEndedIterator<A>> Iterator<A> for Rev<T> {
     #[inline]
     fn next(&mut self) -> Option<A> { self.iter.next_back() }
     #[inline]
     fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
 }
 
-impl<A, T: DoubleEndedIterator<A>> DoubleEndedIterator<A> for Invert<T> {
+impl<A, T: DoubleEndedIterator<A>> DoubleEndedIterator<A> for Rev<T> {
     #[inline]
     fn next_back(&mut self) -> Option<A> { self.iter.next() }
 }
 
 impl<A, T: DoubleEndedIterator<A> + RandomAccessIterator<A>> RandomAccessIterator<A>
-    for Invert<T> {
+    for Rev<T> {
     #[inline]
     fn indexable(&self) -> uint { self.iter.indexable() }
     #[inline]
@@ -2590,12 +2590,12 @@ mod tests {
     }
 
     #[test]
-    fn test_invert() {
+    fn test_rev() {
         let xs = [2, 4, 6, 8, 10, 12, 14, 16];
         let mut it = xs.iter();
         it.next();
         it.next();
-        assert_eq!(it.invert().map(|&x| x).collect::<~[int]>(), ~[16, 14, 12, 10, 8, 6]);
+        assert_eq!(it.rev().map(|&x| x).collect::<~[int]>(), ~[16, 14, 12, 10, 8, 6]);
     }
 
     #[test]
@@ -2662,7 +2662,7 @@ mod tests {
     fn test_double_ended_chain() {
         let xs = [1, 2, 3, 4, 5];
         let ys = ~[7, 9, 11];
-        let mut it = xs.iter().chain(ys.iter()).invert();
+        let mut it = xs.iter().chain(ys.iter()).rev();
         assert_eq!(it.next().unwrap(), &11)
         assert_eq!(it.next().unwrap(), &9)
         assert_eq!(it.next_back().unwrap(), &1)
@@ -2764,10 +2764,10 @@ mod tests {
     }
 
     #[test]
-    fn test_random_access_invert() {
+    fn test_random_access_rev() {
         let xs = [1, 2, 3, 4, 5];
-        check_randacc_iter(xs.iter().invert(), xs.len());
-        let mut it = xs.iter().invert();
+        check_randacc_iter(xs.iter().rev(), xs.len());
+        let mut it = xs.iter().rev();
         it.next();
         it.next_back();
         it.next();
@@ -2833,13 +2833,13 @@ mod tests {
 
     #[test]
     fn test_double_ended_range() {
-        assert_eq!(range(11i, 14).invert().collect::<~[int]>(), ~[13i, 12, 11]);
-        for _ in range(10i, 0).invert() {
+        assert_eq!(range(11i, 14).rev().collect::<~[int]>(), ~[13i, 12, 11]);
+        for _ in range(10i, 0).rev() {
             fail!("unreachable");
         }
 
-        assert_eq!(range(11u, 14).invert().collect::<~[uint]>(), ~[13u, 12, 11]);
-        for _ in range(10u, 0).invert() {
+        assert_eq!(range(11u, 14).rev().collect::<~[uint]>(), ~[13u, 12, 11]);
+        for _ in range(10u, 0).rev() {
             fail!("unreachable");
         }
     }
@@ -2886,11 +2886,11 @@ mod tests {
 
         assert_eq!(range(0i, 5).collect::<~[int]>(), ~[0i, 1, 2, 3, 4]);
         assert_eq!(range(-10i, -1).collect::<~[int]>(), ~[-10, -9, -8, -7, -6, -5, -4, -3, -2]);
-        assert_eq!(range(0i, 5).invert().collect::<~[int]>(), ~[4, 3, 2, 1, 0]);
+        assert_eq!(range(0i, 5).rev().collect::<~[int]>(), ~[4, 3, 2, 1, 0]);
         assert_eq!(range(200, -5).collect::<~[int]>(), ~[]);
-        assert_eq!(range(200, -5).invert().collect::<~[int]>(), ~[]);
+        assert_eq!(range(200, -5).rev().collect::<~[int]>(), ~[]);
         assert_eq!(range(200, 200).collect::<~[int]>(), ~[]);
-        assert_eq!(range(200, 200).invert().collect::<~[int]>(), ~[]);
+        assert_eq!(range(200, 200).rev().collect::<~[int]>(), ~[]);
 
         assert_eq!(range(0i, 100).size_hint(), (100, Some(100)));
         // this test is only meaningful when sizeof uint < sizeof u64
@@ -2902,11 +2902,11 @@ mod tests {
     #[test]
     fn test_range_inclusive() {
         assert_eq!(range_inclusive(0i, 5).collect::<~[int]>(), ~[0i, 1, 2, 3, 4, 5]);
-        assert_eq!(range_inclusive(0i, 5).invert().collect::<~[int]>(), ~[5i, 4, 3, 2, 1, 0]);
+        assert_eq!(range_inclusive(0i, 5).rev().collect::<~[int]>(), ~[5i, 4, 3, 2, 1, 0]);
         assert_eq!(range_inclusive(200, -5).collect::<~[int]>(), ~[]);
-        assert_eq!(range_inclusive(200, -5).invert().collect::<~[int]>(), ~[]);
+        assert_eq!(range_inclusive(200, -5).rev().collect::<~[int]>(), ~[]);
         assert_eq!(range_inclusive(200, 200).collect::<~[int]>(), ~[200]);
-        assert_eq!(range_inclusive(200, 200).invert().collect::<~[int]>(), ~[200]);
+        assert_eq!(range_inclusive(200, 200).rev().collect::<~[int]>(), ~[200]);
     }
 
     #[test]