CustomStrides array constructor

Author: bluss

src/lib.rs

@@ -163,7 +163,7 @@ pub use crate::stacking::{concatenate, stack, stack_new_axis};
 
 pub use crate::math_cell::MathCell;
 pub use crate::impl_views::IndexLonger;
-pub use crate::shape_builder::{Shape, ShapeBuilder, StrideShape};
+pub use crate::shape_builder::{Shape, ShapeBuilder, StrideShape, CustomStrides};
 
 #[macro_use]
 mod macro_utils;

src/shape_builder.rs

@@ -268,3 +268,17 @@ impl<T> ShapeArg for (T, CustomStrides<T>) where T: IntoDimension {
         (self.0.into_dimension(), Strides::Custom(self.1.strides.into_dimension()))
     }
 }
+
+impl<T, D> From<(T, CustomStrides<T>)> for StrideShape<D>
+where
+    D: Dimension,
+    T: IntoDimension<Dim = D>,
+{
+    fn from(value: (T, CustomStrides<T>)) -> Self {
+        let shape = value.0.into_shape();
+        StrideShape {
+            strides: Strides::Custom(value.1.strides.into_dimension()),
+            dim: shape.dim,
+        }
+    }
+}

tests/array-construct.rs

@@ -8,7 +8,7 @@
 use defmac::defmac;
 use ndarray::prelude::*;
 use ndarray::Zip;
-use ndarray::Order;
+use ndarray::{Order, CustomStrides};
 
 #[test]
 fn test_from_shape_fn() {
@@ -259,3 +259,16 @@ fn test_order_constructor() {
     assert_eq!(a.strides(), b.t().strides());
     assert_eq!(a.strides(), c.strides());
 }
+
+#[test]
+fn test_custom_strides() {
+    type Mat<D> = Array<f32, D>;
+    let v = vec![0.; 3 * 3 * 2];
+    let a = Mat::from_shape_vec(((3, 3), CustomStrides((3, 1))), v.clone()).unwrap();
+    let b = Mat::from_shape_vec(((3, 3), CustomStrides((1, 6))), v.clone()).unwrap();
+    let c = Mat::from_shape_vec(((3, 3), CustomStrides((2, 6))), v.clone()).unwrap();
+
+    assert_eq!(a.strides(), &[3, 1]);
+    assert_eq!(b.strides(), &[1, 6]);
+    assert_eq!(c.strides(), &[2, 6]);
+}