Implement + for @-vectors.

Author: msullivan

src/libcore/at_vec.rs

@@ -78,6 +78,16 @@ pure fn build<A>(builder: fn(push: pure fn(+A))) -> @[A] {
     build_sized(4, builder)
 }
 
+// Appending
+#[inline(always)]
+pure fn append<T: copy>(lhs: @[T], rhs: &[const T]) -> @[T] {
+    do build_sized(lhs.len() + rhs.len()) |push| {
+        for vec::each(lhs) |x| { push(x); }
+        for uint::range(0, rhs.len()) |i| { push(rhs[i]); }
+    }
+}
+
+
 /// Apply a function to each element of a vector and return the results
 pure fn map<T, U>(v: &[T], f: fn(T) -> U) -> @[U] {
     do build_sized(v.len()) |push| {
@@ -113,6 +123,21 @@ pure fn from_elem<T: copy>(n_elts: uint, t: T) -> @[T] {
     }
 }
 
+impl extensions<T: copy> of vec_concat<T> for @[T] {
+    #[inline(always)]
+    pure fn +(rhs: &[const T]) -> @[T] {
+        append(self, rhs)
+    }
+}
+
+#[cfg(notest)]
+impl extensions<T: copy> of add<&[const T],@[T]> for @[T] {
+    #[inline(always)]
+    pure fn add(rhs: &[const T]) -> @[T] {
+        append(self, rhs)
+    }
+}
+
 
 mod unsafe {
     type vec_repr = vec::unsafe::vec_repr;
@@ -213,4 +238,10 @@ fn test() {
     assert seq_range(10, 15) == @[10, 11, 12, 13, 14];
     assert from_fn(5, |x| x+1) == @[1, 2, 3, 4, 5];
     assert from_elem(5, 3.14) == @[3.14, 3.14, 3.14, 3.14, 3.14];
-}
+}
+
+#[test]
+fn append_test() {
+    assert @[1,2,3] + @[4,5,6] == @[1,2,3,4,5,6];
+}
+

src/libcore/vec.rs

@@ -1211,7 +1211,7 @@ pure fn riteri<T>(v: &[T], f: fn(uint, T)) {
  * The total number of permutations produced is `len(v)!`.  If `v` contains
  * repeated elements, then some permutations are repeated.
  */
-pure fn permute<T: copy>(v: &[T], put: fn(~[T])) {
+pure fn permute<T: copy>(v: &[const T], put: fn(~[T])) {
     let ln = len(v);
     if ln == 0u {
         put(~[]);
@@ -1221,7 +1221,7 @@ pure fn permute<T: copy>(v: &[T], put: fn(~[T])) {
             let elt = v[i];
             let mut rest = slice(v, 0u, i);
             unchecked {
-                push_all(rest, view(v, i+1u, ln));
+                push_all(rest, const_view(v, i+1u, ln));
                 permute(rest, |permutation| {
                     put(append(~[elt], permutation))
                 })