test: Rewrite nbody and spectralnorm shootout benchmarks

Author: pcwalton

src/libcore/core.rc

@@ -98,6 +98,7 @@ pub use vec::{ImmutableEqVector, ImmutableCopyableVector};
 pub use vec::{OwnedVector, OwnedCopyableVector};
 pub use iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
 pub use iter::{CopyableOrderedIter, CopyableNonstrictIter, Times};
+pub use iter::{ExtendedMutableIter};
 
 pub use num::{Num, NumCast};
 pub use ptr::Ptr;

src/libcore/iter.rs

@@ -45,6 +45,10 @@ pub trait ExtendedIter<A> {
     fn flat_map_to_vec<B,IB: BaseIter<B>>(&self, op: &fn(&A) -> IB) -> ~[B];
 }
 
+pub trait ExtendedMutableIter<A> {
+    fn eachi_mut(&mut self, blk: &fn(uint, &mut A) -> bool);
+}
+
 pub trait EqIter<A:Eq> {
     fn contains(&self, x: &A) -> bool;
     fn count(&self, x: &A) -> uint;

src/libcore/prelude.rs

@@ -33,7 +33,7 @@ pub use container::{Container, Mutable, Map, Set};
 pub use hash::Hash;
 pub use iter::{BaseIter, ReverseIter, MutableIter, ExtendedIter, EqIter};
 pub use iter::{CopyableIter, CopyableOrderedIter, CopyableNonstrictIter};
-pub use iter::Times;
+pub use iter::{Times, ExtendedMutableIter};
 pub use num::{Num, NumCast};
 pub use path::GenericPath;
 pub use path::Path;

src/libcore/vec.rs

@@ -1388,13 +1388,19 @@ pub fn each<'r,T>(v: &'r [T], f: &fn(&'r T) -> bool) {
 /// to mutate the contents as you iterate.
 #[inline(always)]
 pub fn each_mut<'r,T>(v: &'r mut [T], f: &fn(elem: &'r mut T) -> bool) {
-    let mut i = 0;
-    let n = v.len();
-    while i < n {
-        if !f(&mut v[i]) {
-            return;
+    do vec::as_mut_buf(v) |p, n| {
+        let mut n = n;
+        let mut p = p;
+        while n > 0 {
+            unsafe {
+                let q: &'r mut T = cast::transmute_mut_region(&mut *p);
+                if !f(q) {
+                    break;
+                }
+                p = p.offset(1);
+            }
+            n -= 1;
         }
-        i += 1;
     }
 }
 
@@ -1426,6 +1432,22 @@ pub fn eachi<'r,T>(v: &'r [T], f: &fn(uint, v: &'r T) -> bool) {
     }
 }
 
+/**
+ * Iterates over a mutable vector's elements and indices
+ *
+ * Return true to continue, false to break.
+ */
+#[inline(always)]
+pub fn eachi_mut<'r,T>(v: &'r mut [T], f: &fn(uint, v: &'r mut T) -> bool) {
+    let mut i = 0;
+    for each_mut(v) |p| {
+        if !f(i, p) {
+            return;
+        }
+        i += 1;
+    }
+}
+
 /**
  * Iterates over a vector's elements in reverse
  *
@@ -2654,6 +2676,13 @@ impl<'self,A> iter::ExtendedIter<A> for &'self [A] {
     }
 }
 
+impl<'self,A> iter::ExtendedMutableIter<A> for &'self mut [A] {
+    #[inline(always)]
+    pub fn eachi_mut(&mut self, blk: &fn(uint, v: &mut A) -> bool) {
+        eachi_mut(*self, blk)
+    }
+}
+
 // FIXME(#4148): This should be redundant
 impl<A> iter::ExtendedIter<A> for ~[A] {
     pub fn eachi(&self, blk: &fn(uint, v: &A) -> bool) {