Merge pull request #148 from bluss/no-order-map

Use .as_slice_memory_order in .to_owned() and .map()

Author: bluss

.travis.yml

@@ -25,4 +25,4 @@ script:
       cargo test --verbose &&
       ([ -z "$FEATURES" ] || cargo build --verbose --features "$FEATURES") &&
       ([ -z "$FEATURES" ] || cargo test --verbose --features "$FEATURES") &&
-      ([ "$BENCH" != 1 ] || cargo bench --verbose --features "$FEATURES")
+      ([ "$BENCH" != 1 ] || cargo bench --no-run --verbose --features "$FEATURES")

src/impl_methods.rs

@@ -83,13 +83,13 @@ impl<A, S, D> ArrayBase<S, D> where S: Data<Elem=A>, D: Dimension
     pub fn to_owned(&self) -> OwnedArray<A, D>
         where A: Clone
     {
-        let data = if let Some(slc) = self.as_slice() {
-            slc.to_vec()
+        let (data, strides) = if let Some(slc) = self.as_slice_memory_order() {
+            (slc.to_vec(), self.strides.clone())
         } else {
-            self.iter().cloned().collect()
+            (self.iter().cloned().collect(), self.dim.default_strides())
         };
         unsafe {
-            ArrayBase::from_vec_dim_unchecked(self.dim.clone(), data)
+            ArrayBase::from_vec_dim_stride_unchecked(self.dim.clone(), strides, data)
         }
     }
 
@@ -1074,9 +1074,17 @@ impl<A, S, D> ArrayBase<S, D> where S: Data<Elem=A>, D: Dimension
         where F: FnMut(&'a A) -> B,
               A: 'a,
     {
-        let v = ::iterators::to_vec(self.iter().map(f));
-        unsafe {
-            ArrayBase::from_vec_dim_unchecked(self.dim.clone(), v)
+        if let Some(slc) = self.as_slice_memory_order() {
+            let v = ::iterators::to_vec(slc.iter().map(f));
+            unsafe {
+                ArrayBase::from_vec_dim_stride_unchecked(
+                    self.dim.clone(), self.strides.clone(), v)
+            }
+        } else {
+            let v = ::iterators::to_vec(self.iter().map(f));
+            unsafe {
+                ArrayBase::from_vec_dim_unchecked(self.dim.clone(), v)
+            }
         }
     }
 }

src/iterators.rs

@@ -888,13 +888,15 @@ send_sync_read_write!(AxisChunksIterMut);
 /// to deliver exactly as many items as it said it would.
 pub unsafe trait TrustedIterator { }
 
+use std::slice;
 use std::iter;
 use linspace::Linspace;
 
 unsafe impl<F> TrustedIterator for Linspace<F> { }
 unsafe impl<'a, A, D> TrustedIterator for Elements<'a, A, D> { }
 unsafe impl<I, F> TrustedIterator for iter::Map<I, F>
     where I: TrustedIterator { }
+unsafe impl<'a, A> TrustedIterator for slice::Iter<'a, A> { }
 
 
 /// Like Iterator::collect, but only for trusted length iterators

tests/array.rs

@@ -883,6 +883,32 @@ fn test_f_order() {
     assert_eq!(dupc, dupf);
 }
 
+#[test]
+fn to_owned_memory_order() {
+    // check that .to_owned() makes f-contiguous arrays out of f-contiguous
+    // input.
+    let c = arr2(&[[1, 2, 3],
+                   [4, 5, 6]]);
+    let mut f = c.view();
+    f.swap_axes(0, 1);
+    let fo = f.to_owned();
+    assert_eq!(f, fo);
+    assert_eq!(f.strides(), fo.strides());
+}
+
+#[test]
+fn map_memory_order() {
+    let a = arr3(&[[[1, 2, 3],
+                    [4, 5, 6]],
+                   [[7, 8, 9],
+                    [0, -1, -2]]]);
+    let mut v = a.view();
+    v.swap_axes(0, 1);
+    let amap = v.map(|x| *x >= 3);
+    assert_eq!(amap.dim(), v.dim());
+    assert_eq!(amap.strides(), v.strides());
+}
+
 #[test]
 fn test_contiguous() {
     let c = arr3(&[[[1, 2, 3],