auto merge of #6223 : alexcrichton/rust/issue-6183, r=pcwalton

Closes #6183.

The first commit changes the compiler's method of treating a `for` loop, and all the remaining commits are just dealing with the fallout.

The biggest fallout was the `IterBytes` trait, although it's really a whole lot nicer now because all of the `iter_bytes_XX` methods are just and-ed together. Sadly there was a huge amount of stuff that's `cfg(stage0)` gated, but whoever lands the next snapshot is going to have a lot of fun deleting all this code!

1 files changed, 34 insertions, 0 deletions

diff --git a/src/libstd/list.rs b/src/libstd/list.rs
index 8d15508b26e..13ef377fabe 100644
--- a/src/libstd/list.rs
+++ b/src/libstd/list.rs
@@ -140,6 +140,7 @@ pub fn iter<T>(l: @List<T>, f: &fn(&T)) {
 }
 
 /// Iterate over a list
+#[cfg(stage0)]
 pub fn each<T>(l: @List<T>, f: &fn(&T) -> bool) {
     let mut cur = l;
     loop {
@@ -152,9 +153,24 @@ pub fn each<T>(l: @List<T>, f: &fn(&T) -> bool) {
         }
     }
 }
+/// Iterate over a list
+#[cfg(not(stage0))]
+pub fn each<T>(l: @List<T>, f: &fn(&T) -> bool) -> bool {
+    let mut cur = l;
+    loop {
+        cur = match *cur {
+          Cons(ref hd, tl) => {
+            if !f(hd) { return false; }
+            tl
+          }
+          Nil => { return true; }
+        }
+    }
+}
 
 impl<T> MutList<T> {
     /// Iterate over a mutable list
+    #[cfg(stage0)]
     pub fn each(@mut self, f: &fn(&mut T) -> bool) {
         let mut cur = self;
         loop {
@@ -170,6 +186,24 @@ impl<T> MutList<T> {
             }
         }
     }
+    /// Iterate over a mutable list
+    #[cfg(not(stage0))]
+    pub fn each(@mut self, f: &fn(&mut T) -> bool) -> bool {
+        let mut cur = self;
+        loop {
+            let borrowed = &mut *cur;
+            cur = match *borrowed {
+                MutCons(ref mut hd, tl) => {
+                    if !f(hd) {
+                        return false;
+                    }
+                    tl
+                }
+                MutNil => break
+            }
+        }
+        return true;
+    }
 }
 
 #[cfg(test)]