auto merge of #6036 : huonw/rust/core-less-at, r=nikomatsakis

From a cursory `git grep` this removes the last part of `core` that requires on `@` (other than `io` and the task local data section).

It renames `RandRes` to ~~StdRng~~ `IsaacRng` and `XorShiftState` to `XorShiftRng` as well as moving their constructors to static methods. To go with this, it adds `rng()` which is designed to be used when the programmer just wants a random number generator, without caring about which exact algorithm is being used.

It also removes all the `gen_int`, `gen_uint`, `gen_char` (etc) methods on `RngUtil` (by moving the defintions to the actual `Rand` instances). The replacement is using `RngUtil::gen`, either type-inferred or with an annotation (`rng.gen::<uint>()`).

I tried to have the `Rng` and `RngUtil` traits exported by `core::prelude` (since `core::rand` (except for `random()`) is useless without them), but this caused [an explosion of (seemingly unrelated) `error: unresolved import`'s](https://gist.github.com/5451839).

6 files changed, 27 insertions, 61 deletions

diff --git a/src/libstd/bitv.rs b/src/libstd/bitv.rs
index d1f6bf982a7..8bfa2013950 100644
--- a/src/libstd/bitv.rs
+++ b/src/libstd/bitv.rs
@@ -876,6 +876,7 @@ mod tests {
     use core::uint;
     use core::vec;
     use core::rand;
+    use core::rand::Rng;
 
     static bench_bits : uint = 1 << 14;
 
@@ -1424,9 +1425,9 @@ mod tests {
         assert!(a.capacity() == uint::bits);
     }
 
-    fn rng() -> @rand::Rng {
+    fn rng() -> rand::IsaacRng {
         let seed = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
-        rand::seeded_rng(seed)
+        rand::IsaacRng::new_seeded(seed)
     }
 
     #[bench]
diff --git a/src/libstd/sort.rs b/src/libstd/sort.rs
index febaea637ef..db6efdf3f52 100644
--- a/src/libstd/sort.rs
+++ b/src/libstd/sort.rs
@@ -902,12 +902,8 @@ mod tests {
 #[cfg(test)]
 mod test_tim_sort {
     use core::prelude::*;
-
     use sort::tim_sort;
-
     use core::rand::RngUtil;
-    use core::rand;
-    use core::vec;
 
     struct CVal {
         val: float,
@@ -915,8 +911,8 @@ mod test_tim_sort {
 
     impl Ord for CVal {
         fn lt(&self, other: &CVal) -> bool {
-            let rng = rand::Rng();
-            if rng.gen_float() > 0.995 { fail!(~"It's happening!!!"); }
+            let rng = rand::rng();
+            if rng.gen::<float>() > 0.995 { fail!(~"It's happening!!!"); }
             (*self).val < other.val
         }
         fn le(&self, other: &CVal) -> bool { (*self).val <= other.val }
@@ -964,10 +960,9 @@ mod test_tim_sort {
     #[should_fail]
     #[cfg(unix)]
     fn crash_test() {
-        let rng = rand::Rng();
+        let rng = rand::rng();
         let mut arr = do vec::from_fn(1000) |_i| {
-            let randVal = rng.gen_float();
-            CVal { val: randVal }
+            CVal { val: rng.gen() }
         };
 
         tim_sort(arr);
@@ -985,10 +980,9 @@ mod test_tim_sort {
 
     #[test]
     fn test_bad_Ord_impl() {
-        let rng = rand::Rng();
+        let rng = rand::rng();
         let mut arr = do vec::from_fn(500) |_i| {
-            let randVal = rng.gen_uint();
-            DVal { val: randVal }
+            DVal { val: rng.gen() }
         };
 
         tim_sort(arr);
@@ -998,14 +992,8 @@ mod test_tim_sort {
 #[cfg(test)]
 mod big_tests {
     use core::prelude::*;
-
     use sort::*;
-
     use core::rand::RngUtil;
-    use core::rand;
-    use core::task;
-    use core::uint;
-    use core::vec;
 
     #[test]
     fn test_unique() {
@@ -1045,14 +1033,13 @@ mod big_tests {
             }
         }
 
-        let rng = rand::Rng();
+        let rng = rand::rng();
 
         for uint::range(lo, hi) |i| {
             let n = 1 << i;
-            let arr = do vec::from_fn(n) |_i| {
-                rng.gen_float()
+            let mut arr: ~[float] = do vec::from_fn(n) |_i| {
+                rng.gen()
             };
-            let mut arr = arr;
 
             tim_sort(arr); // *sort
             isSorted(arr);
@@ -1076,7 +1063,7 @@ mod big_tests {
                 let size = arr.len();
                 let mut idx = 1;
                 while idx <= 10 {
-                    arr[size-idx] = rng.gen_float();
+                    arr[size-idx] = rng.gen();
                     idx += 1;
                 }
             }
@@ -1085,7 +1072,7 @@ mod big_tests {
 
             for (n/100).times {
                 let idx = rng.gen_uint_range(0, n);
-                arr[idx] = rng.gen_float();
+                arr[idx] = rng.gen();
             }
             tim_sort(arr);
             isSorted(arr);
@@ -1117,12 +1104,12 @@ mod big_tests {
             }
         }
 
-        let rng = rand::Rng();
+        let rng = rand::rng();
 
         for uint::range(lo, hi) |i| {
             let n = 1 << i;
-            let arr = do vec::from_fn(n) |_i| {
-                @rng.gen_float()
+            let arr: ~[@float] = do vec::from_fn(n) |_i| {
+                @rng.gen()
             };
             let mut arr = arr;
 
@@ -1148,7 +1135,7 @@ mod big_tests {
                 let size = arr.len();
                 let mut idx = 1;
                 while idx <= 10 {
-                    arr[size-idx] = @rng.gen_float();
+                    arr[size-idx] = @rng.gen();
                     idx += 1;
                 }
             }
@@ -1157,7 +1144,7 @@ mod big_tests {
 
             for (n/100).times {
                 let idx = rng.gen_uint_range(0, n);
-                arr[idx] = @rng.gen_float();
+                arr[idx] = @rng.gen();
             }
             tim_sort(arr);
             isSorted(arr);
diff --git a/src/libstd/tempfile.rs b/src/libstd/tempfile.rs
index 895ccbc820b..c9bcb3b8952 100644
--- a/src/libstd/tempfile.rs
+++ b/src/libstd/tempfile.rs
@@ -10,13 +10,11 @@
 
 //! Temporary files and directories
 
-use core::os;
 use core::prelude::*;
 use core::rand::RngUtil;
-use core::rand;
 
 pub fn mkdtemp(tmpdir: &Path, suffix: &str) -> Option<Path> {
-    let r = rand::Rng();
+    let r = rand::rng();
     for 1000.times {
         let p = tmpdir.push(r.gen_str(16) + suffix);
         if os::make_dir(&p, 0x1c0) { // 700
diff --git a/src/libstd/test.rs b/src/libstd/test.rs
index addc1da6394..f82cc25e0f6 100644
--- a/src/libstd/test.rs
+++ b/src/libstd/test.rs
@@ -19,20 +19,9 @@ use getopts;
 use sort;
 use term;
 
-use core::cmp::Eq;
-
 use core::to_str::ToStr;
-use core::either::Either;
-use core::either;
-use core::io::WriterUtil;
-use core::io;
 use core::comm::{stream, SharedChan};
-use core::option;
 use core::prelude::*;
-use core::result;
-use core::str;
-use core::task;
-use core::vec;
 
 pub mod rustrt {
     use core::libc::size_t;
@@ -608,12 +597,8 @@ pub mod bench {
     use time::precise_time_ns;
     use test::{BenchHarness, BenchSamples};
     use stats::Stats;
-
-    use core::num;
+    use core::prelude::*;
     use core::rand::RngUtil;
-    use core::rand;
-    use core::u64;
-    use core::vec;
 
     pub impl BenchHarness {
 
@@ -705,7 +690,7 @@ pub mod bench {
         // not met, it may run as long as the Go algorithm.
         pub fn auto_bench(&mut self, f: &fn(&mut BenchHarness)) -> ~[f64] {
 
-            let rng = rand::Rng();
+            let rng = rand::rng();
             let mut magnitude = 10;
             let mut prev_madp = 0.0;
 
diff --git a/src/libstd/timer.rs b/src/libstd/timer.rs
index e862fe6077c..1e48ce5aa6f 100644
--- a/src/libstd/timer.rs
+++ b/src/libstd/timer.rs
@@ -175,11 +175,7 @@ mod test {
 
     use timer::*;
     use uv;
-
-    use core::iter;
     use core::rand::RngUtil;
-    use core::rand;
-    use core::task;
     use core::pipes::{stream, SharedChan};
 
     #[test]
@@ -220,7 +216,7 @@ mod test {
                 let hl_loop_clone = hl_loop.clone();
                 do task::spawn {
                     use core::rand::*;
-                    let rng = Rng();
+                    let rng = rng();
                     for iter::repeat(times) {
                         sleep(&hl_loop_clone, rng.next() as uint % maxms);
                     }
@@ -277,7 +273,7 @@ mod test {
         let hl_loop = uv::global_loop::get();
 
         for iter::repeat(times as uint) {
-            let expected = rand::Rng().gen_str(16u);
+            let expected = rand::rng().gen_str(16u);
             let (test_po, test_ch) = stream::<~str>();
             let hl_loop_clone = hl_loop.clone();
             do task::spawn() {
diff --git a/src/libstd/treemap.rs b/src/libstd/treemap.rs
index ac887c7fdc4..020f4daefd9 100644
--- a/src/libstd/treemap.rs
+++ b/src/libstd/treemap.rs
@@ -698,7 +698,6 @@ mod test_treemap {
     use core::iterator::*;
     use super::*;
     use core::rand::RngUtil;
-    use core::rand;
 
     #[test]
     fn find_empty() {
@@ -835,12 +834,12 @@ mod test_treemap {
         check_equal(ctrl, &map);
         assert!(map.find(&5).is_none());
 
-        let rng = rand::seeded_rng(&[42]);
+        let rng = rand::IsaacRng::new_seeded(&[42]);
 
         for 3.times {
             for 90.times {
-                let k = rng.gen_int();
-                let v = rng.gen_int();
+                let k = rng.gen();
+                let v = rng.gen();
                 if !ctrl.contains(&(k, v)) {
                     assert!(map.insert(k, v));
                     ctrl.push((k, v));