---

yaml
---
r: 57193
b: refs/heads/try
c: 92bf9b6
h: refs/heads/master
i:
  57191: 45edb94
v: v3

Author: emberian

[refs]

@@ -2,7 +2,7 @@
 refs/heads/master: c081ffbd1e845687202a975ea2e698b623e5722f
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 79a2b2eafc3c766cecec8a5f76317693bae9ed17
-refs/heads/try: 225ac216157cf530332cef1c926875e2023e48e6
+refs/heads/try: 92bf9b68da05504e925e2b66ceb9f3e5f1a5b0ee
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c

branches/try/src/libcore/core.rc

@@ -77,7 +77,9 @@ pub use kinds::{Const, Copy, Owned, Durable};
 pub use ops::{Drop};
 #[cfg(stage0)]
 pub use ops::{Add, Sub, Mul, Div, Modulo, Neg, Not};
-#[cfg(not(stage0))]
+#[cfg(stage1)]
+#[cfg(stage2)]
+#[cfg(stage3)]
 pub use ops::{Add, Sub, Mul, Quot, Rem, Neg, Not};
 pub use ops::{BitAnd, BitOr, BitXor};
 pub use ops::{Shl, Shr, Index};
@@ -103,9 +105,7 @@ pub use iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
 pub use iter::{CopyableOrderedIter, CopyableNonstrictIter, Times};
 pub use iter::{ExtendedMutableIter};
 
-pub use num::{Num, NumCast};
-pub use num::{Signed, Unsigned, Integer};
-pub use num::{Round, Fractional, Real, RealExt};
+pub use num::{Num, Signed, Unsigned, Natural, NumCast};
 pub use ptr::Ptr;
 pub use to_str::ToStr;
 pub use clone::Clone;

branches/try/src/libcore/iterator.rs

@@ -312,6 +312,19 @@ impl<A, T: Iterator<A>> Iterator<A> for TakeIterator<T> {
     }
 }
 
+pub struct ScanIterator<'self, A, B, T, St> {
+    priv iter: T,
+    priv f: &'self fn(&mut St, A) -> Option<B>,
+    state: St
+}
+
+impl<'self, A, B, T: Iterator<A>, St> Iterator<B> for ScanIterator<'self, A, B, T, St> {
+    #[inline]
+    fn next(&mut self) -> Option<B> {
+        self.iter.next().chain(|a| (self.f)(&mut self.state, a))
+    }
+}
+
 pub struct UnfoldrIterator<'self, A, St> {
     priv f: &'self fn(&mut St) -> Option<A>,
     state: St
@@ -335,16 +348,25 @@ impl<'self, A, St> Iterator<A> for UnfoldrIterator<'self, A, St> {
     }
 }
 
-pub struct ScanIterator<'self, A, B, T, St> {
-    priv iter: T,
-    priv f: &'self fn(&mut St, A) -> Option<B>,
-    state: St
+/// An infinite iterator starting at `start` and advancing by `step` with each iteration
+pub struct Counter<A> {
+    state: A,
+    step: A
 }
 
-impl<'self, A, B, T: Iterator<A>, St> Iterator<B> for ScanIterator<'self, A, B, T, St> {
-    #[inline]
-    fn next(&mut self) -> Option<B> {
-        self.iter.next().chain(|a| (self.f)(&mut self.state, a))
+pub impl<A> Counter<A> {
+    #[inline(always)]
+    fn new(start: A, step: A) -> Counter<A> {
+        Counter{state: start, step: step}
+    }
+}
+
+impl<A: Add<A, A> + Clone> Iterator<A> for Counter<A> {
+    #[inline(always)]
+    fn next(&mut self) -> Option<A> {
+        let result = self.state.clone();
+        self.state = self.state.add(&self.step); // FIXME: #6050
+        Some(result)
     }
 }
 
@@ -353,6 +375,13 @@ mod tests {
     use super::*;
     use prelude::*;
 
+    #[test]
+    fn test_counter_to_vec() {
+        let mut it = Counter::new(0, 5).take(10);
+        let xs = iter::iter_to_vec(|f| it.advance(f));
+        assert_eq!(xs, ~[0, 5, 10, 15, 20, 25, 30, 35, 40, 45]);
+    }
+
     #[test]
     fn test_iterator_chain() {
         let xs = [0u, 1, 2, 3, 4, 5];