From 92719e438c4cb38067446388d41a2abe651ab9a9 Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijnh@gmail.com>
Date: Mon, 15 Aug 2011 14:32:58 +0200
Subject: [PATCH] Clean up zip and unzip in std::ivec

---
 src/lib/ivec.rs           | 31 +++++++++++++------------------
 src/test/stdtest/ivec.rs  | 14 +++++++-------
 src/test/stdtest/qsort.rs |  6 +++---
 src/test/stdtest/test.rs  |  4 ++--
 4 files changed, 25 insertions(+), 30 deletions(-)

diff --git a/src/lib/ivec.rs b/src/lib/ivec.rs
index d8285b74ad1..be2a1eeea6f 100644
--- a/src/lib/ivec.rs
+++ b/src/lib/ivec.rs
@@ -269,30 +269,25 @@ fn position_pred[T](f: fn(&T) -> bool , v: &[T]) -> option::t[uint] {
     ret none[uint];
 }
 
-fn unzip[@T, @U](v: &[{_0: T, _1: U}]) -> {_0: [T], _1: [U]} {
-    let sz = len(v);
-    if sz == 0u {
-        ret {_0: ~[], _1: ~[]};
-    } else {
-        let rest = slice(v, 1u, sz);
-        let tl = unzip(rest);
-        let a = ~[v.(0)._0];
-        let b = ~[v.(0)._1];
-        ret {_0: a + tl._0, _1: b + tl._1};
+fn unzip[@T, @U](v: &[(T, U)]) -> ([T], [U]) {
+    let as = ~[], bs = ~[];
+    for (a, b) in v {
+        as += ~[a];
+        bs += ~[b];
     }
+    ret (as, bs);
 }
 
-
 // FIXME make the lengths being equal a constraint
-fn zip[@T, @U](v: &[T], u: &[U]) -> [{_0: T, _1: U}] {
-    let sz = len(v);
+fn zip[@T, @U](v: &[T], u: &[U]) -> [(T, U)] {
+    let zipped = ~[];
+    let sz = len(v), i = 0u;
     assert (sz == len(u));
-    if sz == 0u {
-        ret ~[];
-    } else {
-        let rest = zip(slice(v, 1u, sz), slice(u, 1u, sz));
-        ret ~[{_0: v.(0), _1: u.(0)}] + rest;
+    while i < sz {
+        zipped += ~[(v.(i), u.(i))];
+        i += 1u;
     }
+    ret zipped;
 }
 
 // Swaps two elements in a vector
diff --git a/src/test/stdtest/ivec.rs b/src/test/stdtest/ivec.rs
index 961398d8a01..3293fb5eb66 100644
--- a/src/test/stdtest/ivec.rs
+++ b/src/test/stdtest/ivec.rs
@@ -314,15 +314,15 @@ fn test_zip_unzip() {
     let v2 = ~[4, 5, 6];
     let z1 = ivec::zip(v1, v2);
 
-    assert ({_0: 1, _1: 4} == z1.(0));
-    assert ({_0: 2, _1: 5} == z1.(1));
-    assert ({_0: 3, _1: 6} == z1.(2));
+    assert ((1, 4) == z1.(0));
+    assert ((2, 5) == z1.(1));
+    assert ((3, 6) == z1.(2));
 
-    let u1 = ivec::unzip(z1);
+    let (left, right) = ivec::unzip(z1);
 
-    assert ({_0: 1, _1: 4} == {_0: u1._0.(0), _1: u1._1.(0)});
-    assert ({_0: 2, _1: 5} == {_0: u1._0.(1), _1: u1._1.(1)});
-    assert ({_0: 3, _1: 6} == {_0: u1._0.(2), _1: u1._1.(2)});
+    assert ((1, 4) == (left.(0), right.(0)));
+    assert ((2, 5) == (left.(1), right.(1)));
+    assert ((3, 6) == (left.(2), right.(2)));
 }
 
 #[test]
diff --git a/src/test/stdtest/qsort.rs b/src/test/stdtest/qsort.rs
index 1a249de4919..f8928b7a2c2 100644
--- a/src/test/stdtest/qsort.rs
+++ b/src/test/stdtest/qsort.rs
@@ -50,9 +50,9 @@ fn test_simple() {
     sort::quick_sort(lteq, names);
 
     let pairs = ivec::zip(expected, ivec::from_mut(names));
-    for p: {_0: int, _1: int} in pairs {
-        log #fmt("%d %d", p._0, p._1);
-        assert (p._0 == p._1);
+    for (a, b) in pairs {
+        log #fmt("%d %d", a, b);
+        assert (a == b);
     }
 }
 
diff --git a/src/test/stdtest/test.rs b/src/test/stdtest/test.rs
index 7d587e23521..135cfee36c2 100644
--- a/src/test/stdtest/test.rs
+++ b/src/test/stdtest/test.rs
@@ -89,8 +89,8 @@ fn sort_tests() {
     let pairs = ivec::zip(expected, filtered);
 
 
-    for p: {_0: str, _1: test::test_desc} in pairs {
-        assert (p._0 == p._1.name);
+    for (a, b) in pairs {
+        assert (a == b.name);
     }
 }