feat(deep_causality_tensor):

Refactored code organization and improved documentation of public API.

Signed-off-by: Marvin Hansen <[email protected]>

Author: marvin-hansen

deep_causality_tensor/src/types/causal_tensor/api/api_tensor_product.rs

@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: MIT
+ * Copyright (c) "2025" . The DeepCausality Authors and Contributors. All Rights Reserved.
+ */
+use crate::{CausalTensor, CausalTensorError};
+use std::ops::Mul;
+
+impl<T> CausalTensor<T>
+where
+    T: Clone + Default + PartialOrd + Mul<Output = T>,
+{
+    /// Computes the tensor product (also known as the outer product) of two `CausalTensor`s.
+    ///
+    /// The tensor product combines two tensors into a new tensor whose rank is the sum of
+    /// the ranks of the input tensors, and whose shape is the concatenation of their shapes.
+    /// Each element of the resulting tensor is the product of an element from the left-hand side
+    /// tensor and an element from the right-hand side tensor.
+    ///
+    /// This operation is fundamental in linear algebra and tensor calculus, effectively
+    /// creating all possible pairwise products between elements of the input tensors.
+    ///
+    /// # Arguments
+    ///
+    /// * `rhs` - The right-hand side `CausalTensor`.
+    ///
+    /// # Returns
+    ///
+    /// A `Result` which is:
+    /// - `Ok(CausalTensor<T>)` containing the result of the tensor product.
+    /// - `Err(CausalTensorError)` if an error occurs during the operation (e.g., memory allocation).
+    ///
+    /// # Errors
+    ///
+    /// This method can return `CausalTensorError` if the underlying `tensor_product_impl`
+    /// encounters an issue, such as a failure during new tensor creation.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use deep_causality_tensor::CausalTensor;
+    ///
+    /// let lhs = CausalTensor::new(vec![1.0, 2.0], vec![2]).unwrap(); // Shape [2]
+    /// let rhs = CausalTensor::new(vec![3.0, 4.0, 5.0], vec![3]).unwrap(); // Shape [3]
+    ///
+    /// // Expected result:
+    /// // [[1*3, 1*4, 1*5],
+    /// //  [2*3, 2*4, 2*5]]
+    /// // which is [[3.0, 4.0, 5.0], [6.0, 8.0, 10.0]] with shape [2, 3]
+    /// let result = lhs.tensor_product(&rhs).unwrap();
+    ///
+    /// assert_eq!(result.shape(), &[2, 3]);
+    /// assert_eq!(result.as_slice(), &[3.0, 4.0, 5.0, 6.0, 8.0, 10.0]);
+    ///
+    /// // Tensor product with a scalar
+    /// let scalar = CausalTensor::new(vec![10.0], vec![]).unwrap(); // Shape []
+    /// let vector = CausalTensor::new(vec![1.0, 2.0], vec![2]).unwrap(); // Shape [2]
+    /// let result_scalar_vec = scalar.tensor_product(&vector).unwrap();
+    /// assert_eq!(result_scalar_vec.shape(), &[2]);
+    /// assert_eq!(result_scalar_vec.as_slice(), &[10.0, 20.0]);
+    /// ```
+    pub fn tensor_product(
+        &self,
+        rhs: &CausalTensor<T>,
+    ) -> Result<CausalTensor<T>, CausalTensorError> {
+        self.tensor_product_impl(rhs)
+    }
+}

deep_causality_tensor/src/types/causal_tensor/api/api_tensor_reduction.rs

@@ -9,8 +9,6 @@ impl<T> CausalTensor<T>
 where
     T: Clone + Default + PartialOrd,
 {
-    // --- Reduction Operations ---
-
     /// Sums the elements along one or more specified axes.
     ///
     /// The dimensions corresponding to the `axes` provided will be removed from the

deep_causality_tensor/src/types/causal_tensor/api/api_tensor_shape.rs

@@ -8,8 +8,6 @@ impl<T> CausalTensor<T>
 where
     T: Clone + Default + PartialOrd,
 {
-    // --- Shape Manipulation ---
-
     /// Returns a new tensor with the same data but a different shape.
     ///
     /// This is a metadata-only operation; it creates a new `CausalTensor` with a cloned copy

deep_causality_tensor/src/types/causal_tensor/api/api_tensor_view.rs

@@ -8,8 +8,6 @@ impl<T> CausalTensor<T>
 where
     T: Clone + Default + PartialOrd,
 {
-    // --- View Operations ---
-
     /// Creates a new tensor representing a slice of the original tensor along a specified axis.
     ///
     /// This operation extracts a sub-tensor where one dimension has been fixed to a specific index.

deep_causality_tensor/src/types/causal_tensor/api/mod.rs

@@ -3,6 +3,7 @@
  * Copyright (c) "2025" . The DeepCausality Authors and Contributors. All Rights Reserved.
  */
 mod api_ein_sum;
+mod api_tensor_product;
 mod api_tensor_reduction;
 mod api_tensor_shape;
 mod api_tensor_view;

deep_causality_tensor/src/types/causal_tensor/op_tensor_product/mod.rs

@@ -9,7 +9,7 @@ impl<T> CausalTensor<T>
 where
     T: Clone + Default + PartialOrd + Mul<Output = T>,
 {
-    pub fn tensor_product(
+    pub(super) fn tensor_product_impl(
         &self,
         rhs: &CausalTensor<T>,
     ) -> Result<CausalTensor<T>, CausalTensorError> {