From d9cdddeb5f80b11763b6f95fd7eecdef705ed12d Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Tue, 5 Jun 2012 17:26:52 -0700
Subject: [PATCH] stdlib: Introduce ord and eq interfaces. Make
 std::sort::quick_sort3 use them. i=#2348

---
 src/libcore/cmp.rs           | 10 ++++++++++
 src/libcore/core.rc          |  2 ++
 src/libcore/int-template.rs  | 14 ++++++++++++++
 src/libcore/uint-template.rs | 14 ++++++++++++++
 src/libstd/sort.rs           | 13 ++++---------
 5 files changed, 44 insertions(+), 9 deletions(-)
 create mode 100644 src/libcore/cmp.rs

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
new file mode 100644
index 000000000000..aea97cf1649f
--- /dev/null
+++ b/src/libcore/cmp.rs
@@ -0,0 +1,10 @@
+#[doc="Interfaces used for comparison."]
+
+iface ord {
+    fn lt(&&other: self) -> bool;
+}
+
+iface eq {
+    fn eq(&&other: self) -> bool;
+}
+
diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 6b4c7ad7d3ca..efcd424024a1 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -44,6 +44,7 @@ export extfmt;
 export tuple;
 export to_str;
 export dvec, dvec_iter;
+export cmp;
 
 // NDM seems to be necessary for resolve to work
 export option_iter;
@@ -152,6 +153,7 @@ mod tuple;
 
 // Ubiquitous-utility-type modules
 
+mod cmp;
 mod either;
 mod iter;
 mod logging;
diff --git a/src/libcore/int-template.rs b/src/libcore/int-template.rs
index 156724cb0617..4011ac1a18a7 100644
--- a/src/libcore/int-template.rs
+++ b/src/libcore/int-template.rs
@@ -1,4 +1,5 @@
 import T = inst::T;
+import cmp::{eq, ord};
 
 export min_value, max_value;
 export min, max;
@@ -10,6 +11,7 @@ export range;
 export compl;
 export abs;
 export parse_buf, from_str, to_str, to_str_bytes, str;
+export ord, eq;
 
 const min_value: T = -1 as T << (inst::bits - 1 as T);
 const max_value: T = min_value - 1 as T;
@@ -108,6 +110,18 @@ fn to_str_bytes<U>(n: T, radix: uint, f: fn([u8]/&) -> U) -> U {
 #[doc = "Convert to a string"]
 fn str(i: T) -> str { ret to_str(i, 10u); }
 
+impl ord of ord for T {
+    fn lt(&&other: T) -> bool {
+        ret self < other;
+    }
+}
+
+impl eq of eq for T {
+    fn eq(&&other: T) -> bool {
+        ret self == other;
+    }
+}
+
 
 // FIXME: Has alignment issues on windows and 32-bit linux
 #[test]
diff --git a/src/libcore/uint-template.rs b/src/libcore/uint-template.rs
index a63d01e6e8e0..7126fb3d007d 100644
--- a/src/libcore/uint-template.rs
+++ b/src/libcore/uint-template.rs
@@ -1,4 +1,5 @@
 import T = inst::T;
+import cmp::{eq, ord};
 
 export min_value, max_value;
 export min, max;
@@ -10,6 +11,7 @@ export range;
 export compl;
 export to_str, to_str_bytes;
 export from_str, from_str_radix, str, parse_buf;
+export ord, eq;
 
 const min_value: T = 0 as T;
 const max_value: T = 0 as T - 1 as T;
@@ -49,6 +51,18 @@ pure fn compl(i: T) -> T {
     max_value ^ i
 }
 
+impl ord of ord for T {
+    fn lt(&&other: T) -> bool {
+        ret self < other;
+    }
+}
+
+impl eq of eq for T {
+    fn eq(&&other: T) -> bool {
+        ret self == other;
+    }
+}
+
 #[doc = "
 Parse a buffer of bytes
 
diff --git a/src/libstd/sort.rs b/src/libstd/sort.rs
index 7e16578fd9c8..76c71d7ed2aa 100644
--- a/src/libstd/sort.rs
+++ b/src/libstd/sort.rs
@@ -1,5 +1,6 @@
 #[doc = "Sorting methods"];
 import vec::len;
+import int::{eq, ord};
 
 export le;
 export merge_sort;
@@ -141,7 +142,6 @@ fn qsort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
     qsort3::<T>(compare_func_lt, compare_func_eq, arr, i, right);
 }
 
-// FIXME: This should take lt and eq types (#2348)
 #[doc = "
 Fancy quicksort. Sorts a mut vector in place.
 
@@ -152,10 +152,9 @@ According to these slides this is the algorithm of choice for
 
 This is an unstable sort.
 "]
-fn quick_sort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
-                       arr: [mut T]) {
+fn quick_sort3<T: copy ord eq>(arr: [mut T]) {
     if len::<T>(arr) == 0u { ret; }
-    qsort3::<T>(compare_func_lt, compare_func_eq, arr, 0,
+    qsort3::<T>({ |x, y| x.lt(y) }, { |x, y| x.eq(y) }, arr, 0,
                 (len::<T>(arr) as int) - 1);
 }
 
@@ -163,11 +162,7 @@ fn quick_sort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
 mod test_qsort3 {
     fn check_sort(v1: [mut int], v2: [mut int]) {
         let len = vec::len::<int>(v1);
-        fn lt(&&a: int, &&b: int) -> bool { ret a < b; }
-        fn equal(&&a: int, &&b: int) -> bool { ret a == b; }
-        let f1 = lt;
-        let f2 = equal;
-        quick_sort3::<int>(f1, f2, v1);
+        quick_sort3::<int>(v1);
         let mut i = 0u;
         while i < len {
             log(debug, v2[i]);