Some perf fixes, although vec::slice is still too slow (Issue #2719)

src/libcore/str.rs

@@ -1727,7 +1727,7 @@ mod unsafe {
         vec::reserve(v, len + 1u);
         vec::as_buf(v) {|b| ptr::memcpy(b, buf, len); }
         vec::unsafe::set_len(v, len);
-        v += [0u8];
+        vec::push(v, 0u8);
 
         assert is_utf8(v);
         ret ::unsafe::transmute(v);

src/libcore/vec.rs

@@ -255,14 +255,18 @@ pure fn slice<T: copy>(v: [const T]/&, start: uint, end: uint) -> [T] {
     assert (start <= end);
     assert (end <= len(v));
     let mut result = [];
-    unchecked{reserve(result, end - start)}
+
+//    unchecked {
+//        push_all(result, view(v, start, end));
+//    }
+
     let mut i = start;
     while i < end { result += [v[i]]; i += 1u; }
     ret result;
 }
 
 #[doc = "Return a slice that points into another slice."]
-pure fn view<T: copy>(v: [T]/&, start: uint, end: uint) -> [T]/&a {
+pure fn view<T: copy>(v: [const T]/&a, start: uint, end: uint) -> [T]/&a {
     assert (start <= end);
     assert (end <= len(v));
     unpack_slice(v) {|p, _len|
@@ -454,6 +458,7 @@ fn push_slow<T>(&v: [const T], +initval: T) {
 
 #[inline(always)]
 fn push_all<T: copy>(&v: [const T], rhs: [const T]/&) {
+    reserve(v, v.len() + rhs.len());
     for uint::range(0u, rhs.len()) {|i|
         push(v, rhs[i]);
     }

src/libstd/ebml.rs

@@ -193,7 +193,7 @@ impl writer for writer {
         write_vuint(self.writer, tag_id);
 
         // Write a placeholder four-byte size.
-        self.size_positions += [self.writer.tell()];
+        vec::push(self.size_positions, self.writer.tell());
         let zeroes: [u8]/& = [0u8, 0u8, 0u8, 0u8]/&;
         self.writer.write(zeroes);
     }

src/libstd/sort.rs

@@ -43,9 +43,9 @@ fn merge_sort<T: copy>(le: le<T>, v: [const T]) -> [T] {
         let mut b_ix = 0u;
         while a_ix < a_len && b_ix < b_len {
             if le(a[a_ix], b[b_ix]) {
-                rs += [a[a_ix]];
+                vec::push(rs, a[a_ix]);
                 a_ix += 1u;
-            } else { rs += [b[b_ix]]; b_ix += 1u; }
+            } else { vec::push(rs, b[b_ix]); b_ix += 1u; }
         }
         rs += vec::slice(a, a_ix, a_len);
         rs += vec::slice(b, b_ix, b_len);

src/test/bench/shootout-k-nucleotide.rs

@@ -36,7 +36,7 @@ fn sort_and_fmt(mm: hashmap<[u8], uint>, total: uint) -> str {
 
    // map -> [(k,%)]
    mm.each(fn&(key: [u8], val: uint) -> bool {
-      pairs += [(key, pct(val, total))];
+      vec::push(pairs, (key, pct(val, total)));
       ret true;
    });
 

src/test/bench/shootout-mandelbrot.rs

@@ -72,7 +72,7 @@ fn chanmb(i: uint, size: uint, ch: comm::chan<line>) -> ()
     for uint::range(0_u, size/8_u) {
         |j|
         let x = {re: xincr*(j as f64) - 1.5f64, im: y};
-        crv += [fillbyte(x, incr)];
+        vec::push(crv, fillbyte(x, incr));
     };
     comm::send(ch, {i:i, b:crv});
 }

src/test/bench/task-perf-one-million.rs

@@ -21,7 +21,7 @@ fn calc(children: uint, parent_ch: comm::chan<msg>) {
     iter::repeat (children) {||
         alt check comm::recv(port) {
           ready(child_ch) {
-            child_chs += [child_ch];
+            vec::push(child_chs, child_ch);
           }
         }
     }

src/test/run-pass/vec-slice.rs

@@ -1,7 +1,6 @@
-// xfail-test
 fn main() {
-  let vec<int> v = [1,2,3,4,5];
-  auto v2 = v.(1,2);
-  assert (v2.(0) == 2);
-  assert (v2.(1) == 3);
+    let  v = [1,2,3,4,5];
+    let v2 = vec::slice(v, 1, 3);
+    assert (v2[0] == 2);
+    assert (v2[1] == 3);
 }