Add layout module

Author: termoshtt

src/layout.rs

@@ -0,0 +1,58 @@
+
+use ndarray::*;
+
+use super::error::*;
+
+pub enum Layout {
+    C((usize, usize)),
+    F((usize, usize)),
+}
+
+impl Layout {
+    pub fn size(&self) -> (usize, usize) {
+        match self {
+            &Layout::C(s) => s,
+            &Layout::F(s) => s,
+        }
+    }
+}
+
+pub trait AllocatedArray2D {
+    type Scalar;
+    fn layout(&self) -> LResult<Layout>;
+    fn square_layout(&self) -> LResult<Layout>;
+    fn as_allocated(&self) -> LResult<&[Self::Scalar]>;
+}
+
+impl<A, S> AllocatedArray2D for ArrayBase<S, Ix2>
+    where S: Data<Elem = A>
+{
+    type Scalar = A;
+
+    fn layout(&self) -> LResult<Layout> {
+        let strides = self.strides();
+        if ::std::cmp::min(strides[0], strides[1]) != 1 {
+            return Err(StrideError::new(strides[0], strides[1]).into());
+        }
+        if strides[0] < strides[1] {
+            Ok(Layout::C((self.rows(), self.cols())))
+        } else {
+            Ok(Layout::F((self.rows(), self.cols())))
+        }
+    }
+
+    fn square_layout(&self) -> LResult<Layout> {
+        let l = self.layout()?;
+        let (n, m) = l.size();
+        if n == m {
+            Ok(l)
+        } else {
+            Err(NotSquareError::new(n, m).into())
+        }
+    }
+
+    fn as_allocated(&self) -> LResult<&[A]> {
+        let slice = self.as_slice_memory_order().ok_or(MemoryContError::new())?;
+        Ok(slice)
+    }
+}

src/lib.rs

@@ -44,6 +44,7 @@ extern crate derive_new;
 
 pub mod impls;
 pub mod error;
+pub mod layout;
 
 pub mod vector;
 pub mod matrix;