Start refactoring the stride.

candle-core/src/layout.rs

@@ -0,0 +1,47 @@
+use crate::Shape;
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct Layout {
+    shape: Shape,
+    // The strides are given in number of elements and not in bytes.
+    stride: Vec<usize>,
+    start_offset: usize,
+}
+
+impl Layout {
+    pub fn contiguous<S: Into<Shape>>(shape: S) -> Self {
+        let shape = shape.into();
+        let stride = shape.stride_contiguous();
+        Self {
+            shape,
+            stride,
+            start_offset: 0,
+        }
+    }
+
+    pub fn dims(&self) -> &[usize] {
+        self.shape.dims()
+    }
+
+    pub fn shape(&self) -> &Shape {
+        &self.shape
+    }
+
+    pub fn stride(&self) -> &[usize] {
+        &self.stride
+    }
+
+    pub fn start_offset(&self) -> usize {
+        self.start_offset
+    }
+
+    /// Returns true if the data is stored in a C contiguous (aka row major) way.
+    pub fn is_contiguous(&self) -> bool {
+        self.shape.is_contiguous(&self.stride)
+    }
+
+    /// Returns true if the data is stored in a Fortran contiguous (aka column major) way.
+    pub fn is_fortran_contiguous(&self) -> bool {
+        self.shape.is_fortran_contiguous(&self.stride)
+    }
+}