Switch over to new range_rev semantics; fix rust-lang#5270.

Author: pnkfelix

src/libextra/smallintmap.rs

@@ -157,8 +157,8 @@ impl<V> SmallIntMap<V> {
     /// Visit all key-value pairs in reverse order
     pub fn each_reverse<'a>(&'a self, it: &fn(uint, &'a V) -> bool) -> bool {
         for uint::range_rev(self.v.len(), 0) |i| {
-            match self.v[i - 1] {
-              Some(ref elt) => if !it(i - 1, elt) { return false; },
+            match self.v[i] {
+              Some(ref elt) => if !it(i, elt) { return false; },
               None => ()
             }
         }

src/libstd/num/int_macros.rs

@@ -186,9 +186,10 @@ pub fn range(lo: $T, hi: $T, it: &fn($T) -> bool) -> bool {
 }
 
 #[inline]
-/// Iterate over the range [`hi`..`lo`)
+/// Iterate over the range (`hi`..`lo`]
 pub fn range_rev(hi: $T, lo: $T, it: &fn($T) -> bool) -> bool {
-    range_step(hi, lo, -1 as $T, it)
+    if hi == min_value { return true; }
+    range_step_inclusive(hi-1, lo, -1 as $T, it)
 }
 
 /// Computes the bitwise complement

src/libstd/num/uint_macros.rs

@@ -166,9 +166,10 @@ pub fn range(lo: $T, hi: $T, it: &fn($T) -> bool) -> bool {
 }
 
 #[inline]
-/// Iterate over the range [`hi`..`lo`)
+/// Iterate over the range (`hi`..`lo`]
 pub fn range_rev(hi: $T, lo: $T, it: &fn($T) -> bool) -> bool {
-    range_step(hi, lo, -1 as $T_SIGNED, it)
+    if hi == min_value { return true; }
+    range_step_inclusive(hi-1, lo, -1 as $T_SIGNED, it)
 }
 
 /// Computes the bitwise complement

src/libstd/run.rs

@@ -669,7 +669,7 @@ fn spawn_process_os(prog: &str, args: &[~str],
             fail!("failure in dup3(err_fd, 2): %s", os::last_os_error());
         }
         // close all other fds
-        for int::range_rev(getdtablesize() as int - 1, 2) |fd| {
+        for int::range_rev(getdtablesize() as int, 3) |fd| {
             close(fd as c_int);
         }
 

src/libstd/trie.rs

@@ -261,7 +261,7 @@ impl<T> TrieNode<T> {
 
     fn each_reverse<'a>(&'a self, f: &fn(&uint, &'a T) -> bool) -> bool {
         for uint::range_rev(self.children.len(), 0) |idx| {
-            match self.children[idx - 1] {
+            match self.children[idx] {
                 Internal(ref x) => if !x.each_reverse(|i,t| f(i,t)) { return false },
                 External(k, ref v) => if !f(&k, v) { return false },
                 Nothing => ()

src/test/run-pass/num-range-rev.rs

@@ -40,13 +40,13 @@ pub fn main() {
     // int and uint have same result for
     //   Sum{100 > i >= 2} == (Sum{1 <= i <= 99} - 1) == n*(n+1)/2 - 1 for n=99
     let mut sum = 0u;
-    for uint_range_rev(99, 1) |i| {
+    for uint_range_rev(100, 2) |i| {
         sum += i;
     }
     assert_eq!(sum, 4949);
 
     let mut sum = 0i;
-    for int_range_rev(99, 1) |i| {
+    for int_range_rev(100, 2) |i| {
         sum += i;
     }
     assert_eq!(sum, 4949);
@@ -55,17 +55,17 @@ pub fn main() {
     // elements are visited in correct order
     let primes = [2,3,5,7,11];
     let mut prod = 1i;
-    for uint_range_rev(4, 0) |i| {
+    for uint_range_rev(5, 0) |i| {
         println(fmt!("uint 4 downto 0: %u", i));
         prod *= int::pow(primes[i], i);
     }
-    assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3);
+    assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3*1);
     let mut prod = 1i;
-    for int_range_rev(4, 0) |i| {
+    for int_range_rev(5, 0) |i| {
         println(fmt!("int 4 downto 0: %d", i));
         prod *= int::pow(primes[i], i as uint);
     }
-    assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3);
+    assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3*1);
 
 
     // range and range_rev are symmetric.
@@ -74,7 +74,7 @@ pub fn main() {
         sum_up += i;
     }
     let mut sum_down = 0u;
-    for uint_range_rev(29, 9) |i| {
+    for uint_range_rev(30, 10) |i| {
         sum_down += i;
     }
     assert_eq!(sum_up, sum_down);
@@ -84,7 +84,7 @@ pub fn main() {
         sum_up += i;
     }
     let mut sum_down = 0;
-    for int_range_rev(9, -21) |i| {
+    for int_range_rev(10, -20) |i| {
         sum_down += i;
     }
     assert_eq!(sum_up, sum_down);
@@ -96,7 +96,7 @@ pub fn main() {
     }
 
     for uint_range_rev(0, 1) |_| {
-        // fail!("range should be empty when start-1 underflows");
+        fail!("range should be empty when start-1 underflows");
     }
 
     // range iterations do not wrap/underflow