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burn_tensor/tensor/api/
base.rs

1#![allow(clippy::single_range_in_vec_init)]
2use crate::backend::ExecutionError;
3use crate::check::unwrap_shape_reshape;
4
5use burn_backend::Scalar;
6pub use burn_backend::tensor::BasicOps;
7
8use alloc::vec::Vec;
9
10use alloc::format;
11use alloc::string::String;
12use alloc::vec;
13
14use burn_std::{SliceOps, stub::RwLock};
15use core::iter::repeat;
16use core::{fmt::Debug, ops::Range};
17use serde::{Deserialize, Deserializer};
18
19use crate::{AsIndex, Slice, SliceArg, wrap_index};
20use crate::{
21    Bool, ElementConversion, Float, Int, Shape, TensorData, TensorKind, TensorMetadata,
22    backend::Backend, check,
23};
24use crate::{DType, Element};
25use crate::{IndexingUpdateOp, TensorCreationOptions};
26use crate::{cast::ToElement, check::TensorCheck};
27use serde::{Serialize, Serializer};
28
29/// A tensor with a given backend, shape and data type.
30///
31/// # Indexing
32/// Indexing a tensor can be done using [`slice`](Tensor::slice) for all tensor types
33/// or [`select`](Tensor::select) for numeric types.
34///
35/// ## Example
36///
37/// ```rust
38/// use burn_tensor::backend::Backend;
39/// use burn_tensor::Tensor;
40/// use burn_tensor::Int;
41///
42/// fn example<B: Backend>() {
43///     let device = Default::default();
44///
45///     let tensor = Tensor::<B, 2>::from_data(
46///         [
47///             [3.0, 4.9, 2.0],
48///             [2.0, 1.9, 3.0],
49///             [6.0, 1.5, 7.0],
50///             [3.0, 4.9, 9.0],
51///         ],
52///         &device,
53///     );
54///
55///     // Slice the tensor to get the second and third rows:
56///     // [[2.0, 1.9, 3.0], [6.0, 1.5, 7.0]]
57///     // The resulting tensor will have dimensions [2, 3].
58///     let slice = tensor.clone().slice([1..3]);
59///     println!("{slice}");
60///
61///     // Slice the tensor to get the first two rows and the first 2 columns:
62///     // [[3.0, 4.9], [2.0, 1.9]]
63///     // The resulting tensor will have dimensions [2, 2].
64///     let slice = tensor.clone().slice([0..2, 0..2]);
65///     println!("{slice}");
66///
67///     // Index the tensor along the dimension 1 to get the elements 0 and 2:
68///     // [[3.0, 2.0], [2.0, 3.0], [6.0, 7.0], [3.0, 9.0]]
69///     // The resulting tensor will have dimensions [4, 2]
70///     let indices = Tensor::<B, 1, Int>::from_data([0, 2], &device);
71///     let indexed = tensor.select(1, indices);
72///     println!("{indexed}");
73/// }
74/// ```
75#[derive(new, Clone, Debug)]
76pub struct Tensor<B, const D: usize, K = Float>
77where
78    B: Backend,
79    K: TensorKind<B>,
80{
81    pub(crate) primitive: K::Primitive,
82}
83
84impl<B, const D: usize, K, T> From<T> for Tensor<B, D, K>
85where
86    B: Backend,
87    K: BasicOps<B>,
88    T: Into<TensorData>,
89{
90    fn from(value: T) -> Self {
91        Tensor::from_data(value.into(), &Default::default())
92    }
93}
94
95impl<B, const D: usize, K> Tensor<B, D, K>
96where
97    B: Backend,
98    K: BasicOps<B>,
99    K::Elem: Element,
100{
101    /// Executes an operation on the tensor and modifies its value.
102    ///
103    /// # Notes
104    ///
105    /// This won't necessarily reuse the same tensor data/buffer, but it should if there is
106    /// no other reference pointing to the same tensor.
107    ///
108    /// Wrapping operations with inplace is not an optimization, it's mainly there if you
109    /// want to mutate a tensor by using owned operations. A plausible usage would be to
110    /// update the weights of a mutable model reference.
111    pub fn inplace<F: FnOnce(Self) -> Self>(&mut self, func: F) {
112        let mut tensor_owned = Tensor::empty([0; D], &self.device());
113        core::mem::swap(&mut tensor_owned, self);
114
115        let mut tensor_new = func(tensor_owned);
116        core::mem::swap(&mut tensor_new, self);
117    }
118
119    /// Converts the tensor into a primitive tensor.
120    pub fn into_primitive(self) -> K::Primitive {
121        self.primitive
122    }
123
124    /// Converts from a primitive tensor into a tensor.
125    pub fn from_primitive(tensor: K::Primitive) -> Self {
126        Self::new(tensor)
127    }
128
129    /// Returns the number of dimensions of the tensor.
130    pub fn rank(&self) -> usize {
131        self.primitive.rank()
132    }
133
134    /// Returns the tensor primitive data type.
135    ///
136    /// # Note
137    /// Some element types are encoded in different primitive types depending on the backend
138    /// (e.g., bool could be encoded as `u8` or `u32`).
139    pub fn dtype(&self) -> DType {
140        self.primitive.dtype()
141    }
142
143    /// Create an empty tensor of the given shape.
144    ///
145    /// # Arguments
146    ///
147    /// - `shape`: The shape of the tensor.
148    /// - `device`: The device where the tensor will be created.
149    ///
150    /// # Example
151    /// ```rust
152    /// use burn_tensor::backend::Backend;
153    /// use burn_tensor::Tensor;
154    ///
155    /// fn example<B: Backend>() {
156    ///    let device = Default::default();
157    ///    // Create an empty tensor with dimensions [2, 3, 4].
158    ///    let tensor = Tensor::<B, 3>::empty([2, 3, 4], &device);
159    /// }
160    /// ```
161    pub fn empty<S: Into<Shape>>(shape: S, options: impl Into<TensorCreationOptions<B>>) -> Self {
162        let opt = options.into();
163        let shape = shape.into();
164        let dtype = opt.resolve_policy(K::Elem::dtype());
165        check!(TensorCheck::creation_ops::<D>("Empty", &shape));
166        Self::new(K::empty(shape, &opt.device, dtype))
167    }
168
169    /// Create a tensor of the given shape where each element is zero.
170    ///
171    /// # Example
172    ///
173    /// ```rust
174    /// use burn_tensor::backend::Backend;
175    /// use burn_tensor::{Tensor, Shape};
176    ///
177    /// fn example<B: Backend>() {
178    ///    let device = B::Device::default();
179    ///    let tensor = Tensor::<B, 2>::zeros(Shape::new([2, 3]), &device);
180    ///    println!("{tensor}");
181    ///    // [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]
182    /// }
183    /// ```
184    pub fn zeros<S: Into<Shape>>(shape: S, options: impl Into<TensorCreationOptions<B>>) -> Self {
185        let opt = options.into();
186        let shape = shape.into();
187        let dtype = opt.resolve_policy(K::Elem::dtype());
188        check!(TensorCheck::creation_ops::<D>("Zeros", &shape));
189        Self::new(K::zeros(shape, &opt.device, dtype))
190    }
191
192    /// Returns a new tensor with the same shape, dtype, and device as the current tensor filled with zeros.
193    ///
194    /// # Example
195    ///
196    /// ```rust
197    /// use burn_tensor::backend::Backend;
198    /// use burn_tensor::{Tensor, Shape};
199    ///
200    /// fn example<B: Backend>() {
201    ///   let device = B::Device::default();
202    ///   let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
203    ///   let tensor = tensor.zeros_like();
204    ///   println!("{tensor}");
205    ///   // [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]
206    /// }
207    /// ```
208    pub fn zeros_like(&self) -> Self {
209        Self::new(K::zeros(self.shape(), &self.device(), self.dtype()))
210    }
211
212    /// Create a tensor of the given shape where each element is one.
213    ///
214    /// # Example
215    ///
216    /// ```rust
217    /// use burn_tensor::backend::Backend;
218    /// use burn_tensor::{Tensor, Shape};
219    ///
220    /// fn example<B: Backend>() {
221    ///   let device = B::Device::default();
222    ///   let tensor = Tensor::<B, 2>::ones(Shape::new([2, 3]), &device);
223    ///   println!("{tensor}");
224    ///   // [[1.0, 1.0, 1.0], [1.0, 1.0, 1.0]]
225    /// }
226    /// ```
227    pub fn ones<S: Into<Shape>>(shape: S, options: impl Into<TensorCreationOptions<B>>) -> Self {
228        let opt = options.into();
229        let shape = shape.into();
230        let dtype = opt.resolve_policy(K::Elem::dtype());
231        check!(TensorCheck::creation_ops::<D>("Ones", &shape));
232        Self::new(K::ones(shape, &opt.device, dtype))
233    }
234
235    /// Returns a new tensor with the same shape, dtype, and device as the current tensor filled with ones.
236    ///
237    /// # Example
238    ///
239    /// ```rust
240    /// use burn_tensor::backend::Backend;
241    /// use burn_tensor::{Tensor, Shape};
242    ///
243    /// fn example<B: Backend>() {
244    ///    let device = B::Device::default();
245    ///    let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
246    ///    let tensor = tensor.ones_like();
247    ///    println!("{tensor}");
248    ///    // [[1.0, 1.0, 1.0], [1.0, 1.0, 1.0]]
249    /// }
250    /// ```
251    pub fn ones_like(&self) -> Self {
252        Self::new(K::ones(self.shape(), &self.device(), self.dtype()))
253    }
254
255    /// Create a tensor of the given shape where each element is equal to the provided value.
256    ///
257    /// # Example
258    ///
259    /// ```rust
260    /// use burn_tensor::backend::Backend;
261    /// use burn_tensor::{Tensor, Shape};
262    ///
263    /// fn example<B: Backend>() {
264    ///   let device = B::Device::default();
265    ///   let tensor = Tensor::<B, 2>::full(Shape::new([2, 3]), 5.0, &device);
266    ///   println!("{tensor}");
267    ///   // [[5.0, 5.0, 5.0], [5.0, 5.0, 5.0]]
268    /// }
269    /// ```
270    pub fn full<S: Into<Shape>, E: ElementConversion>(
271        shape: S,
272        fill_value: E,
273        options: impl Into<TensorCreationOptions<B>>,
274    ) -> Self {
275        let opt = options.into();
276        let shape = shape.into();
277        let dtype = opt.resolve_policy(K::Elem::dtype());
278        check!(TensorCheck::creation_ops::<D>("Full", &shape));
279        Self::new(K::full(
280            shape,
281            Scalar::new(fill_value, &dtype),
282            &opt.device,
283            dtype,
284        ))
285    }
286
287    /// Returns a new tensor with the same shape, dtype, and device as the current tensor,
288    /// filled with the provided value.
289    ///
290    /// # Example
291    ///
292    /// ```rust
293    /// use burn_tensor::backend::Backend;
294    /// use burn_tensor::{Tensor, Shape};
295    ///
296    /// fn example<B: Backend>() {
297    ///    let device = B::Device::default();
298    ///    let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
299    ///    let tensor = tensor.full_like(5.0);
300    ///    println!("{tensor}");
301    ///    // [[5.0, 5.0, 5.0], [5.0, 5.0, 5.0]]
302    /// }
303    /// ```
304    pub fn full_like<E: ElementConversion>(&self, fill_value: E) -> Self {
305        let dtype = self.dtype();
306        Self::new(K::full(
307            self.shape(),
308            Scalar::new(fill_value, &dtype),
309            &self.device(),
310            dtype,
311        ))
312    }
313
314    /// Returns the dimensions of the current tensor.
315    ///
316    /// # Example
317    /// ```rust
318    /// use burn_tensor::backend::Backend;
319    /// use burn_tensor::Tensor;
320    ///
321    /// fn example<B: Backend>() {
322    ///   let device = Default::default();
323    ///   let tensor = Tensor::<B, 3>::ones([2, 3, 4], &device);
324    ///   let dims = tensor.dims(); // [2, 3, 4]
325    ///   println!("{dims:?}");
326    /// }
327    /// ```
328    pub fn dims(&self) -> [usize; D] {
329        Self::shape(self).dims()
330    }
331
332    /// Returns the shape of the current tensor.
333    ///
334    /// # Example
335    /// ```rust
336    /// use burn_tensor::backend::Backend;
337    /// use burn_tensor::Tensor;
338    ///
339    /// fn example<B: Backend>() {
340    ///    let device = Default::default();
341    ///    let tensor = Tensor::<B, 3>::ones([2, 3, 4], &device);
342    ///    // Shape { dims: [2, 3, 4] }
343    ///    let shape = tensor.shape();
344    /// }
345    /// ```
346    pub fn shape(&self) -> Shape {
347        self.primitive.shape()
348    }
349
350    /// Reshape the tensor to have the given shape.
351    ///
352    /// The tensor has the same data and number of elements as the input.
353    ///
354    /// A `-1` in the shape is used to infer the remaining dimensions, e.g.: `[2, -1]`
355    /// will reshape the tensor with [2, 3, 4] dimensions to [2, 12].
356    ///
357    /// A `0` in the shape instructs to keep the current dimension from the original tensor,
358    /// e.g.: `[2, 0, 4]` will reshape the tensor with [2, 3, 4] dimensions to [2, 3, 4].
359    /// This is useful when reshaping tensors with unknown dimensions and combining with `-1`
360    /// to infer the remaining dimensions, e.g. `[0, -1]` will reshape the tensor
361    /// with [1, 3, 4] dimensions to [1, 12].
362    ///
363    /// # Arguments
364    /// - `shape`: The new shape of the tensor.
365    ///
366    /// # Panics
367    /// - If the tensor contains more than one `-1` in the shape.
368    /// - If the tensor contains values that are not positive (other than -1).
369    /// - If the shape does not match the number of elements of the original shape.
370    ///
371    /// # Example
372    ///
373    /// ```rust
374    /// use burn_tensor::backend::Backend;
375    /// use burn_tensor::Tensor;
376    ///
377    /// fn example<B: Backend>() {
378    ///    let device = Default::default();
379    ///    // Create a tensor with dimensions [2, 3, 4]
380    ///    let tensor = Tensor::<B, 3>::ones([2, 3, 4], &device);
381    ///    // Reshape it to [2, 12], where 12 is inferred from the number of elements.
382    ///    let reshaped = tensor.reshape([2, -1]);
383    ///    println!("{reshaped}");
384    /// }
385    /// ```
386    pub fn reshape<const D2: usize, S: ReshapeArgs<D2>>(self, shape: S) -> Tensor<B, D2, K> {
387        // Convert reshape args to shape
388        let shape = shape.into_shape::<D2>(self.shape());
389        Tensor::new(K::reshape(self.primitive, shape))
390    }
391
392    /// Transpose the tensor.
393    ///
394    /// For a 2D tensor, this is the standard matrix transpose. For `D > 2`, the transpose is
395    /// applied on the last two dimensions. For example, the transpose of a tensor with shape
396    /// `[1, 2, 3, 4]` will have shape `[1, 2, 4, 3]`.
397    ///
398    /// See also [`permute`](Tensor::permute).
399    ///
400    /// # Arguments
401    ///
402    /// * `tensor` - The tensor to transpose.
403    ///
404    /// # Returns
405    ///
406    /// The transposed tensor.
407    ///
408    /// # Example
409    ///
410    /// ```rust
411    /// use burn_tensor::backend::Backend;
412    /// use burn_tensor::Tensor;
413    ///
414    /// fn example<B: Backend>() {
415    ///     let device = Default::default();
416    ///     // Create a 2D tensor of shape [2, 3]
417    ///     let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
418    ///
419    ///     // Transpose the tensor:
420    ///     // [[1.0, 5.0], [-2.0, 9.0], [3.0, 6.0]]
421    ///     // The resulting tensor will have dimensions [3, 2].
422    ///     let transposed = tensor.transpose();
423    ///     println!("{transposed}");
424    /// }
425    /// ```
426    pub fn transpose(self) -> Tensor<B, D, K> {
427        Tensor::new(K::transpose(self.primitive))
428    }
429
430    /// Alias for `transpose`.
431    #[inline(always)]
432    pub fn t(self) -> Tensor<B, D, K> {
433        self.transpose()
434    }
435
436    /// Swaps two dimensions of a tensor.
437    ///
438    /// This is a no-op when `dim1 == dim2`, assuming both are within bounds.
439    ///
440    /// # Arguments
441    ///
442    /// * `tensor` - The tensor to swap the dimensions of.
443    /// * `dim1` - The first dimension to swap, supports negative indexing.
444    /// * `dim2` - The second dimension to swap, supports negative indexing.
445    ///
446    /// # Returns
447    ///
448    /// The tensor with the dimensions swapped.
449    ///
450    /// # Panics
451    ///
452    /// When dimensions are out of bounds.
453    ///
454    /// # Example
455    ///
456    /// ```rust
457    /// use burn_tensor::backend::Backend;
458    /// use burn_tensor::Tensor;
459    ///
460    /// fn example<B: Backend>() {
461    ///     let device = Default::default();
462    ///     // Create a 2D tensor of shape [2, 3]
463    ///     let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
464    ///
465    ///     // Swap the dimensions 0 and -1 (equivalent to `tensor.transpose()`):
466    ///     // [[1.0, 5.0], [-2.0, 9.0], [3.0, 6.0]]
467    ///     // The resulting tensor will have dimensions [3, 2].
468    ///     let swapped = tensor.swap_dims(0, -1);
469    ///     println!("{swapped}");
470    /// }
471    /// ```
472    pub fn swap_dims<Dim1, Dim2>(self, dim1: Dim1, dim2: Dim2) -> Tensor<B, D, K>
473    where
474        Dim1: AsIndex,
475        Dim2: AsIndex,
476    {
477        let dim1 = dim1.expect_dim_index(D);
478        let dim2 = dim2.expect_dim_index(D);
479        check!(TensorCheck::swap_dims::<D>(dim1, dim2));
480        if dim1 == dim2 {
481            self
482        } else {
483            Tensor::new(K::swap_dims(self.primitive, dim1, dim2))
484        }
485    }
486
487    /// Permute the dimensions of the tensor.
488    ///
489    /// This is a no-op when the resolved `axes` match the current order.
490    ///
491    /// # Arguments
492    ///
493    /// * `axes` - The new order of the dimensions. The length of the axes
494    ///   must be equal to the number of dimensions of the tensor.
495    ///   The values must be unique and in the range of the number of dimensions.
496    ///   The values can be negative, in which case they are used as an offset from the end.
497    ///
498    /// # Returns
499    ///
500    /// The tensor with the dimensions permuted.
501    ///
502    /// # Example
503    ///
504    /// ```rust
505    /// use burn_tensor::backend::Backend;
506    /// use burn_tensor::Tensor;
507    ///
508    /// fn example<B: Backend>() {
509    ///     let device = Default::default();
510    ///     // Create a 2D tensor of shape [3, 2]
511    ///     let tensor = Tensor::<B, 2>::from_data([[1.0, 5.0], [-2.0, 9.0], [3.0, 6.0]], &device);
512    ///
513    ///     // Permute the dimensions 1 and 0:
514    ///     // [[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]]
515    ///     // The resulting tensor will have dimensions [3, 2].
516    ///     let permuted = tensor.permute([1, 0]);
517    ///     println!("{permuted}");
518    /// }
519    /// ```
520    pub fn permute<Dim>(self, axes: [Dim; D]) -> Tensor<B, D, K>
521    where
522        Dim: AsIndex,
523    {
524        let mut no_op = true;
525        let mut fixed_axes = [0; D];
526        for (i, axis) in axes.into_iter().enumerate() {
527            let dim = axis.expect_dim_index(D);
528            no_op &= dim == i;
529            fixed_axes[i] = dim;
530        }
531
532        if no_op {
533            self
534        } else {
535            check!(TensorCheck::permute(fixed_axes));
536            Tensor::new(K::permute(self.primitive, &fixed_axes))
537        }
538    }
539
540    /// Moves the dimension(s) of input at the position(s) in source to the position(s) in destination.
541    ///
542    /// Other dimensions of input that are not explicitly moved remain in their original order and appear
543    /// at the positions not specified in destination.
544    ///
545    /// # Arguments
546    ///
547    /// * `src` - The dimension(s) to move. The values must be unique and in the range of the number of dimensions.
548    ///   The values can be negative, in which case they are used as an offset from the end.
549    ///
550    /// * `dst` - Destination positions for each of the original dims. These must also be unique.
551    ///
552    /// # Panics
553    ///
554    /// - If the source and destination dimensions are not of the same length.
555    /// - If the source and destination vectors contain duplicate values.
556    /// - If the source and destination vectors contain values that are out of bounds.
557    ///
558    /// # Returns
559    ///
560    /// The tensor with the dimensions moved.
561    ///
562    /// # Example
563    ///
564    /// ```rust
565    /// use burn_tensor::backend::Backend;
566    /// use burn_tensor::Tensor;
567    ///
568    /// fn example<B: Backend>() {
569    ///     let device = Default::default();
570    ///     // Create a 3D tensor of shape [3, 2, 1]
571    ///     let tensor = Tensor::<B, 3>::from_data([[[1.0], [5.0]], [[-2.0], [9.0]], [[3.0], [6.0]]], &device);
572    ///
573    ///     // Move the dimensions 0 and 1:
574    ///     // [[[1.0], [-2.0], [3.0]], [[5.0], [9.0], [6.0]]]
575    ///     // The resulting tensor will have dimensions [2, 3, 1].
576    ///     let moved = tensor.movedim(1, 0);
577    ///     println!("{moved}");
578    /// }
579    /// ```
580    ///
581    /// # Note
582    ///
583    /// This is a syntactic sugar for `permute`. It is used widely enough, so we define a separate Op
584    /// for it
585    pub fn movedim<S1: MovedimArgs, S2: MovedimArgs>(self, src: S1, dst: S2) -> Tensor<B, D, K> {
586        let source_dims = src.into_dim_vec::<D>();
587        let destination_dims = dst.into_dim_vec::<D>();
588
589        check!(TensorCheck::movedim_args_length(
590            &source_dims,
591            &destination_dims
592        ));
593
594        let mut m = [-1; D];
595        for (&d, &s) in destination_dims.iter().zip(source_dims.iter()) {
596            m[d] = s as isize;
597        }
598        let mut axes: [isize; D] = [0; D];
599        let mut source_i = 0;
600        for (dest_i, item) in axes.iter_mut().enumerate().take(D) {
601            *item = if m[dest_i] != -1 {
602                m[dest_i]
603            } else {
604                while source_dims.contains(&source_i) {
605                    source_i += 1;
606                }
607                let result = source_i as isize;
608                source_i += 1;
609                result
610            };
611        }
612
613        self.permute(axes)
614    }
615
616    /// Reverse the order of elements in the tensor along the given dimensions.
617    ///
618    /// # Arguments
619    ///
620    /// * `axes` - The dimensions to reverse. The values must be unique and in the range of the number of dimensions.
621    ///   The values can be negative, in which case they are used as an offset from the end.
622    ///
623    /// # Returns
624    ///
625    /// The tensor with the axes flipped.
626    ///
627    /// # Example
628    ///
629    /// ```rust
630    /// use burn_tensor::backend::Backend;
631    /// use burn_tensor::Tensor;
632    ///
633    /// fn example<B: Backend>() {
634    ///     let device = Default::default();
635    ///     // Create a 2D tensor with dimensions [4, 3]
636    ///     let tensor = Tensor::<B, 2>::from_data(
637    ///         [
638    ///             [3.0, 4.9, 2.0],
639    ///             [2.0, 1.9, 3.0],
640    ///             [4.0, 5.9, 8.0],
641    ///             [1.4, 5.8, 6.0],
642    ///         ],
643    ///         &device,
644    ///     );
645    ///
646    ///     // Flip the elements in dimensions 0 and 1:
647    ///     // [[6.0, 5.8, 1.4],
648    ///     //  [8.0, 5.9, 4.0],
649    ///     //  [3.0, 1.9, 2.0],
650    ///     //  [2.0, 4.9, 3.0]]
651    ///     // The resulting tensor will have dimensions [4, 3].
652    ///     let flipped = tensor.flip([0, 1]);
653    ///     println!("{flipped}");
654    /// }
655    /// ```
656    pub fn flip<const N: usize>(self, axes: [isize; N]) -> Tensor<B, D, K> {
657        // Convert the axes to usize and handle negative values without using vector
658        let mut transformed_axes: [usize; N] = [0; N];
659        for (i, &x) in axes.iter().enumerate() {
660            transformed_axes[i] = if x < 0 {
661                (D as isize + x) as usize
662            } else {
663                x as usize
664            };
665        }
666
667        // Check if the axes are valid
668        check!(TensorCheck::flip(D, &transformed_axes));
669
670        Tensor::new(K::flip(self.primitive, &transformed_axes))
671    }
672
673    /// Flatten the tensor along a given range of dimensions.
674    ///
675    /// This function collapses the specified range of dimensions into a single dimension,
676    /// effectively flattening the tensor in that range.
677    ///
678    /// # Arguments
679    ///
680    /// - `start_dim`: The starting dimension of the range to be flattened,
681    ///   supports negative indexing.
682    /// - `end_dim`: The ending dimension of the range to be flattened (inclusive),
683    ///   supports negative indexing.
684    ///
685    /// # Type Parameters
686    ///
687    /// - `D2`: The resulting number of dimensions in the flattened tensor.
688    ///
689    /// # Returns
690    ///
691    /// A new `Tensor<B, D2, K>` instance with the specified range of dimensions flattened.
692    ///
693    /// # Example
694    ///
695    /// ```rust
696    ///
697    /// use burn_tensor::backend::Backend;
698    /// use burn_tensor::{Tensor, Shape};
699    ///
700    /// fn example<B: Backend>() {
701    ///     let device = Default::default();
702    ///     // Create a 3D tensor with dimensions [2, 3, 4]
703    ///     let tensor = Tensor::<B, 3>::ones(Shape::new([2, 3, 4]), &device);
704    ///
705    ///     // Flatten the tensor from dimensions 1 to 2 (inclusive).
706    ///     // The resulting tensor will have dimensions [2, 12]
707    ///     let flattened: Tensor<B, 2> = tensor.flatten(1, 2);
708    ///     println!("{flattened}");
709    /// }
710    /// ```
711    pub fn flatten<const D2: usize>(
712        self,
713        start_dim: impl AsIndex,
714        end_dim: impl AsIndex,
715    ) -> Tensor<B, D2, K> {
716        let start_dim = start_dim.expect_dim_index(D);
717        let end_dim = end_dim.expect_dim_index(D);
718        check!(TensorCheck::flatten::<D, D2>(start_dim, end_dim));
719        let new_shape = self.shape().flatten_dims(start_dim, end_dim);
720
721        Tensor::new(K::reshape(self.primitive, new_shape))
722    }
723
724    /// Squeeze the tensor along all dimensions, removing dimensions
725    /// of size one, and effectively reducing the rank of the tensor.
726    ///
727    /// # Type Parameters
728    ///
729    ///  - `D2`: The resulting number of dimensions in the squeezed tensor.
730    ///
731    /// # Returns
732    ///
733    /// A new `Tensor<B, D2, K>` instance with the specified dimension removed.
734    ///
735    /// # Example
736    ///
737    /// ```rust
738    ///
739    /// use burn_tensor::backend::Backend;
740    /// use burn_tensor::{Tensor, Shape};
741    ///
742    /// fn example<B: Backend>() {
743    ///     let device = Default::default();
744    ///     // Create a 4D tensor with dimensions [1, 3, 1, 3]
745    ///     let tensor = Tensor::<B, 4>::from_data(
746    ///         [[[[3.0, 4.9, 2.0]], [[2.0, 1.9, 3.0]], [[4.0, 5.9, 8.0]]]],
747    ///         &device,
748    ///     );
749    ///
750    ///     // Squeeze the tensor dimensions.
751    ///     // The resulting tensor will have dimensions [3, 3].
752    ///     let squeezed = tensor.squeeze::<2>();
753    ///     println!("{squeezed}");
754    /// }
755    /// ```
756    pub fn squeeze<const D2: usize>(self) -> Tensor<B, D2, K> {
757        let new_dims = self
758            .shape()
759            .iter()
760            .filter_map(|&dim| if dim == 1 { None } else { Some(dim) })
761            .collect::<Vec<_>>();
762        check!(TensorCheck::squeeze_dims_len::<D2>(new_dims.len()));
763
764        Tensor::new(K::reshape(self.primitive, new_dims.into()))
765    }
766
767    /// Squeeze the tensor along the given dimension, removing the specified dimension
768    /// of size one, and effectively reducing the rank of the tensor by one.
769    ///
770    /// # Arguments
771    ///
772    /// - `dim`: The dimension to be squeezed.
773    ///
774    /// # Type Parameters
775    ///
776    ///  - `D2`: The resulting number of dimensions in the squeezed tensor.
777    ///
778    /// # Panics
779    ///
780    /// If the size in the squeezed dimension is not 1.
781    ///
782    /// # Returns
783    ///
784    /// A new `Tensor<B, D2, K>` instance with the specified dimension removed.
785    ///
786    /// # Example
787    ///
788    /// ```rust
789    ///
790    /// use burn_tensor::backend::Backend;
791    /// use burn_tensor::{Tensor, Shape};
792    ///
793    /// fn example<B: Backend>() {
794    ///     let device = Default::default();
795    ///     // Create a 3D tensor with dimensions [3, 1, 3]
796    ///     let tensor = Tensor::<B, 3>::from_data(
797    ///         [[[3.0, 4.9, 2.0]], [[2.0, 1.9, 3.0]], [[4.0, 5.9, 8.0]]],
798    ///         &device,
799    ///     );
800    ///
801    ///     // Squeeze the dimension 1.
802    ///     // The resulting tensor will have dimensions [3, 3].
803    ///     let squeezed = tensor.squeeze_dim::<2>(1);
804    ///     println!("{squeezed}");
805    /// }
806    /// ```
807    pub fn squeeze_dim<const D2: usize>(self, dim: usize) -> Tensor<B, D2, K> {
808        check!(TensorCheck::squeeze::<D2>(dim, &self.shape()));
809
810        let current_dims = self.shape();
811        let mut new_dims: [usize; D2] = [0; D2];
812
813        new_dims[..dim].copy_from_slice(&current_dims[..dim]);
814        new_dims[dim..].copy_from_slice(&current_dims[dim + 1..]);
815
816        check!(TensorCheck::squeeze_dims_len::<D2>(new_dims.len()));
817        Tensor::new(K::reshape(self.primitive, new_dims.into()))
818    }
819
820    /// Removes specified dimensions of size 1 from a tensor's shape. This function takes a tensor and
821    /// an array of dimensions (`dims`) to be squeezed. If `dims` is provided, only the dimensions
822    /// specified in this array will be removed. Each dimension in `dims` should correspond to a size of 1
823    /// in the tensor; otherwise, the dimension will not be squeezed. If `dims` is empty, all single-dimensional entries
824    /// in the tensor will be removed. If entries in `dims` are negative, then dimensions will be counted
825    /// from the back.
826    ///
827    /// # Arguments
828    ///
829    /// - `dims`: The dimension(s) to be squeezed.
830    ///
831    /// # Type Parameters
832    ///
833    ///  - `D2`: The resulting number of dimensions in the squeezed tensor.
834    ///
835    /// # Returns
836    ///
837    /// A new `Tensor<B, D2, K>` instance with the specified dimensions removed.
838    ///
839    /// # Example
840    ///
841    /// ```rust
842    ///
843    /// use burn_tensor::backend::Backend;
844    /// use burn_tensor::{Tensor, Shape};
845    ///
846    /// fn example<B: Backend>() {
847    ///     let device = Default::default();
848    ///     // Create a 4D tensor with dimensions [2, 1, 4, 1]
849    ///     let tensor = Tensor::<B, 4>::ones(Shape::new([2, 1, 4, 1]), &device);
850    ///
851    ///     // Squeeze the dimensions 1 and 3.
852    ///     // The resulting tensor will have dimensions [2, 4].
853    ///     let squeezed: Tensor<B, 2> = tensor.squeeze_dims(&[1, 3]);
854    ///     println!("{squeezed}");
855    /// }
856    /// ```
857    pub fn squeeze_dims<const D2: usize>(self, dims: &[isize]) -> Tensor<B, D2, K> {
858        let current_dims = self.shape();
859        let mut dim_indices: Vec<usize>;
860
861        // Check if dims is empty, if yes then assign dim_indices all single-dimensional entries
862        if dims.is_empty() {
863            dim_indices = current_dims
864                .iter()
865                .enumerate()
866                .filter_map(|(index, &dim)| if dim == 1 { Some(index) } else { None })
867                .collect();
868        } else {
869            // If negative dims, count from the back
870            dim_indices = dims
871                .iter()
872                .map(|&d| {
873                    if d < 0 {
874                        (current_dims.len() as isize + d) as usize
875                    } else {
876                        d as usize
877                    }
878                })
879                .collect();
880        }
881
882        // Sort indices and remove duplicates
883        dim_indices.sort_unstable();
884        dim_indices.dedup();
885
886        // Make sure squeeze_dims doesn't result in a tensor with < 1 dimensions
887        check!(TensorCheck::squeeze_dims_input::<D2>(
888            &dim_indices,
889            &current_dims
890        ));
891
892        // Calculate new dimensions
893        let mut new_dims = Vec::new();
894        for (index, &dim_size) in current_dims.iter().enumerate() {
895            // Exclude the dimension if it's explicitly marked for squeezing
896            if dim_indices.contains(&index) {
897                check!(TensorCheck::squeeze::<D2>(index, &current_dims));
898                continue;
899            }
900            new_dims.push(dim_size);
901        }
902
903        // Check that after squeezing, we still respect the D2 size
904        check!(TensorCheck::squeeze_dims_len::<D2>(new_dims.len()));
905
906        Tensor::new(K::reshape(self.primitive, new_dims.into()))
907    }
908
909    /// Unsqueeze the current tensor. Create new leading dimensions to fit the given size.
910    ///
911    /// # Type Parameters
912    ///
913    ///  - `D2`: The resulting number of dimensions in the unsqueezed tensor.
914    ///
915    /// # Panics
916    ///
917    /// If the output size `D2` is smaller than the current number of dimensions.
918    ///
919    /// # Returns
920    ///
921    /// A new `Tensor<B, D2, K>` instance with the specified dimensions added.
922    ///
923    /// # Example
924    ///
925    /// ```rust
926    /// use burn_tensor::backend::Backend;
927    /// use burn_tensor::{Tensor, Shape};
928    ///
929    /// fn example<B: Backend>() {
930    ///     let device = Default::default();
931    ///     // Create a 2D tensor with dimensions [3, 3]
932    ///     let tensor = Tensor::<B, 2>::ones(Shape::new([3, 3]), &device);
933    ///     // Unsqueeze the tensor up to 4 dimensions.
934    ///     // The resulting tensor will have dimensions [1, 1, 3, 3].
935    ///     let unsqueezed = tensor.unsqueeze::<4>();
936    ///     println!("{unsqueezed}");
937    /// }
938    /// ```
939    pub fn unsqueeze<const D2: usize>(self) -> Tensor<B, D2, K> {
940        check!(TensorCheck::unsqueeze::<D, D2>());
941
942        let mut dims = [1; D2];
943        let num_ones = D2 - D;
944        let shape = self.shape();
945
946        dims[num_ones..(D + num_ones)].copy_from_slice(&shape[..D]);
947
948        let shape = Shape::new(dims);
949        self.reshape(shape)
950    }
951
952    /// Creates a new tensor with a dimension of size one inserted at the specified position.
953    ///
954    /// # Example
955    ///
956    /// ```rust
957    /// use burn_tensor::backend::Backend;
958    /// use burn_tensor::{Tensor, Shape};
959    ///
960    /// fn example<B: Backend>() {
961    ///     let device = Default::default();
962    ///     // Create a 2D tensor with dimensions [3, 3]
963    ///     let tensor = Tensor::<B, 2>::ones(Shape::new([3, 3]), &device);
964    ///     // Unsqueeze the dimension 1.
965    ///     // The resulting tensor will have dimensions [3, 1, 3].
966    ///     let unsqueezed: Tensor<B, 3> = tensor.unsqueeze_dim(1);
967    ///     println!("{unsqueezed}");
968    /// }
969    /// ```
970    pub fn unsqueeze_dim<const D2: usize>(self, dim: usize) -> Tensor<B, D2, K> {
971        check!(TensorCheck::unsqueeze_dim::<D, D2>(dim));
972
973        let mut dims = [1; D2];
974        let shape = self.shape();
975
976        dims[0..dim].copy_from_slice(&shape[0..dim]);
977
978        if dim < D {
979            dims[dim] = 1;
980            dims[(dim + 1)..].copy_from_slice(&shape[dim..]);
981        } else {
982            dims[dim] = 1;
983        }
984
985        let shape = Shape::new(dims);
986        self.reshape(shape)
987    }
988
989    /// Creates a new tensor with added dimensions of size one inserted at the specified indices.
990    /// The indices can be negative, in which case they are counted from the last to the first dimension.
991    /// the axes can contain duplicates, in which case the number of dimensions inserted at the index
992    /// is the number of duplicates.
993    /// # Example
994    ///
995    /// ```rust
996    /// use burn_tensor::backend::Backend;
997    /// use burn_tensor::{Tensor, Shape};
998    ///
999    /// fn example<B: Backend>() {
1000    ///     let device = Default::default();
1001    ///     // Create a 3D tensor with dimensions [3, 4, 5]
1002    ///     let tensor = Tensor::<B, 3>::ones(Shape::new([3, 4, 5]), &device);
1003    ///     // Unsqueeze the leading dimension (0) once and the trailing dimension (-1) twice.
1004    ///     // The resulting tensor will have dimensions [1, 3, 4, 5, 1, 1].
1005    ///     let unsqueezed: Tensor<B, 6> = tensor.unsqueeze_dims(&[0, -1, -1]);
1006    ///     println!("{unsqueezed}");
1007    /// }
1008    /// ```
1009    pub fn unsqueeze_dims<const D2: usize>(self, axes: &[impl AsIndex]) -> Tensor<B, D2, K> {
1010        let mut new_dims = [1; D2];
1011        let old_dims = self.shape();
1012        //for checking if the dimension is in the acceptable range
1013
1014        //part 1: convert the negative indices to positive
1015        let mut neg_offset = D2;
1016        let mut dim_indices = axes
1017            .iter()
1018            .map(|d| {
1019                let d = d.as_index();
1020                // check if the dimension is in the acceptable range
1021                check!(TensorCheck::unsqueeze_dims::<{ D2 }>(d));
1022                (if d < 0 {
1023                    neg_offset -= 1; // handle multiple negative indices (decrease dim value in reverse)
1024                    d + neg_offset as isize + 1
1025                } else {
1026                    d
1027                }) as usize
1028            })
1029            .collect::<Vec<usize>>();
1030
1031        //sort the indices
1032        dim_indices.sort_unstable();
1033
1034        //Now use this to copy the chunks of the dims
1035        let mut prev_idx: usize = 0;
1036        let mut current_left_b: usize = 0;
1037        let mut current_right_b: usize = 0;
1038        let mut offset: usize = 0;
1039        dim_indices.iter().for_each(|d| {
1040            //check if there is space for at least one dimension
1041            if prev_idx < *d {
1042                current_right_b = *d - offset;
1043                //copy the chunks of the dims
1044                if current_right_b < D {
1045                    new_dims[prev_idx..*d]
1046                        .copy_from_slice(&old_dims[current_left_b..current_right_b]);
1047                } else {
1048                    new_dims[prev_idx..*d].copy_from_slice(&old_dims[current_left_b..]);
1049                }
1050                prev_idx = *d + 1;
1051                //offset is equal to the number of extracted elements from the original shape
1052                offset += current_right_b - current_left_b;
1053                current_left_b = current_right_b;
1054            } else {
1055                //it's sorted so the only reason this would happen
1056                //is if multiple indices are the same
1057                prev_idx += 1;
1058            }
1059        });
1060        //copy over anything past the index of the last new dimension
1061        if current_left_b < D {
1062            new_dims[prev_idx..].copy_from_slice(&old_dims[current_left_b..]);
1063        }
1064
1065        //lastly, create the shape and reshape
1066        let shape = Shape::new(new_dims);
1067        self.reshape(shape)
1068    }
1069
1070    /// Roll operation along a specific dimension; wrapping around the elements.
1071    ///
1072    /// ## Parameters
1073    ///
1074    /// - `shift`: The roll extent; supports negative values and wraps around.
1075    /// - `dim`: The dimension to roll; supports negative indexing.
1076    ///
1077    /// ## Returns
1078    ///
1079    /// A new tensor with the specified dimension rolled by the given shift amount.
1080    pub fn roll_dim<Shift, Dim>(self, shift: Shift, dim: Dim) -> Self
1081    where
1082        Shift: AsIndex,
1083        Dim: AsIndex,
1084    {
1085        let dim = dim.expect_dim_index(D);
1086        let size = self.shape()[dim];
1087        if size == 0 {
1088            // If the dimension is empty, return the tensor as is.
1089            return self;
1090        }
1091
1092        let shift = wrap_index(shift, size);
1093        if shift == 0 {
1094            // If the shift is zero, return the tensor as is.
1095            return self;
1096        }
1097
1098        self.unchecked_roll_dim(shift, dim)
1099    }
1100
1101    /// Internal implementation of `roll_dim` that does not canonicalize dimensions or shifts.
1102    ///
1103    /// ## Parameters
1104    ///
1105    /// - `shift`: The number of positions to shift; must be (0 < shift < size).
1106    /// - `dim`: The dimension to roll; must be a valid index for the tensor's shape.
1107    ///
1108    /// ## Returns
1109    ///
1110    /// A new tensor with the specified dimension rolled by the given shift amount.
1111    #[inline(always)]
1112    fn unchecked_roll_dim(self, shift: usize, dim: usize) -> Self {
1113        #[cfg(debug_assertions)]
1114        {
1115            let size = self.shape()[dim];
1116            assert!(
1117                0 < shift && shift < size,
1118                "Expected: 0 < shift < size: found shift={shift}, size={size}",
1119            );
1120            assert!(
1121                dim < self.shape().num_dims(),
1122                "Expected: dim < num_dims: found dim={dim}, num_dims={size}",
1123            );
1124        }
1125
1126        Tensor::cat(
1127            vec![
1128                self.clone().slice_dim(dim, shift..),
1129                self.slice_dim(dim, ..shift),
1130            ],
1131            dim,
1132        )
1133    }
1134
1135    /// Roll operation.
1136    ///
1137    /// Note: unlike ``pytorch``, `dims` and `shifts` must have the same length.
1138    ///
1139    /// A given `dim` may be rolled multiple times, and the shifts will be applied sequentially.
1140    ///
1141    /// ## Parameters
1142    ///
1143    /// - `shifts`: A slice of shifts corresponding to each dimension;
1144    ///   supports negative values and wraps around.
1145    /// - `dims`: A slice of dimensions to roll; supports negative indexing.
1146    ///
1147    /// ## Returns
1148    ///
1149    /// A new tensor with the specified dimensions rolled by the given shifts.
1150    pub fn roll<Shift, Dim>(self, shifts: &[Shift], dims: &[Dim]) -> Self
1151    where
1152        Shift: AsIndex,
1153        Dim: AsIndex,
1154    {
1155        assert_eq!(
1156            dims.len(),
1157            shifts.len(),
1158            "Dimensions and shifts must align; found dims={dims:#?}, shifts={shifts:#?}",
1159        );
1160
1161        // This is a fair amount of complexity, which could be replaced
1162        // by a simple canonicalization of `dims` and wrapping of `shifts`.
1163        // The work is done here to ensure that any roll operation
1164        // which could be a no-op is a no-op; simplifying the accounting
1165        // needed by backend-specific implementations of the inner roll op.
1166
1167        let item_count = dims.len();
1168
1169        let shape = self.shape();
1170
1171        // Accumulate the effective shifts for each dimension.
1172        let mut accumulated_shifts: Vec<isize> = vec![0; shape.len()];
1173        for i in 0..item_count {
1174            let dim = dims[i].expect_dim_index(D);
1175            accumulated_shifts[dim] += shifts[i].as_index();
1176        }
1177
1178        // Do this after we've checked the validity of `dims` and `shifts`.
1179        if self.shape().num_elements() == 0 {
1180            // If the tensor is empty, return it as is.
1181            return self;
1182        }
1183
1184        // Wrap the accumulated shifts, and filter out empty dimensions.
1185        let mut effective_dims: Vec<usize> = Vec::with_capacity(item_count);
1186        let mut effective_shifts: Vec<usize> = Vec::with_capacity(item_count);
1187        for dim in 0..shape.len() {
1188            // `wrap_index` should inline, and has a fast-exit path for zero shifts.
1189            let shift = wrap_index(accumulated_shifts[dim], shape[dim]);
1190            if shift == 0 {
1191                continue;
1192            }
1193
1194            effective_dims.push(dim);
1195            effective_shifts.push(shift);
1196        }
1197
1198        // If no shifts are needed, return the original tensor.
1199        if effective_shifts.is_empty() {
1200            return self;
1201        }
1202
1203        // At this point:
1204        // - `dims` contains the effective dimensions to roll, in index order,
1205        // - `shifts` contains the effective usize shifts for each dimension.
1206        // - Every shift is non-zero, and less than the size of the corresponding dimension.
1207        self.unchecked_roll(&effective_shifts, &effective_dims)
1208    }
1209
1210    /// `roll` internal implementation.
1211    ///
1212    /// ## Parameters
1213    ///
1214    /// - `shifts`: A slice of shifts corresponding to each dimension;
1215    ///   must be non-empty, the same length as `dims`, and all ``1..<size>``.
1216    /// - `dims`: A slice of dimensions to roll; must be non-empty;
1217    ///   the same length as `shifts`, and must not contain repeats.
1218    ///
1219    /// ## Panics
1220    ///
1221    /// Panics if the shifts and dimensions do not align, or if dimensions contain repeats.
1222    ///
1223    /// ## Returns
1224    ///
1225    /// A new tensor with the specified dimensions rolled by the given shifts.
1226    #[inline(always)]
1227    fn unchecked_roll(self, shifts: &[usize], dims: &[usize]) -> Self {
1228        #[cfg(debug_assertions)]
1229        {
1230            assert!(!shifts.is_empty());
1231            assert_eq!(
1232                shifts.len(),
1233                dims.len(),
1234                "Shifts and dimensions must align; found {} shifts and {} dims",
1235                shifts.len(),
1236                dims.len()
1237            );
1238
1239            let mut unique_dims = dims.to_vec();
1240            unique_dims.dedup();
1241
1242            assert_eq!(
1243                unique_dims.len(),
1244                dims.len(),
1245                "Dimensions must not contain repeats; found {} unique dims and {} total dims",
1246                unique_dims.len(),
1247                dims.len()
1248            )
1249        }
1250
1251        let x = self.unchecked_roll_dim(shifts[0], dims[0]);
1252
1253        if dims.len() == 1 {
1254            x
1255        } else {
1256            x.unchecked_roll(&shifts[1..], &dims[1..])
1257        }
1258    }
1259
1260    /// Returns a tensor containing the elements selected from the given slices.
1261    ///
1262    /// This method provides flexible tensor slicing with support for various range types,
1263    /// negative indices, and stepped slicing. The method accepts both single slices and
1264    /// arrays of slices, with the [`s!`] macro providing convenient syntax for complex patterns.
1265    ///
1266    /// # Arguments
1267    ///
1268    /// * `slices` - Can be:
1269    ///   - A single range for 1D slicing (e.g., `0..5`, `..`, `2..`)
1270    ///   - An array of ranges (e.g., `[0..2, 1..4]`)
1271    ///   - The [`s!`] macro output for advanced slicing with steps
1272    ///   - a `&Vec<Slice>` or `&[Slice]`
1273    ///
1274    /// # Behavior
1275    ///
1276    /// - Supports partial and full slicing in any number of dimensions
1277    /// - Handles negative indices by wrapping from the end (-1 is the last element)
1278    /// - Automatically clamps ranges that exceed tensor dimensions
1279    /// - Supports stepped slicing for selecting every nth element
1280    /// - Negative steps reverse the selection order
1281    ///
1282    /// # Panics
1283    ///
1284    /// - If the number of slices exceeds the tensor's dimensions
1285    /// - If a range is descending (e.g., 2..1) or empty (e.g., 1..1) without negative step
1286    /// - If a step is zero
1287    ///
1288    /// # Examples
1289    ///
1290    /// ```rust
1291    /// use burn_tensor::backend::Backend;
1292    /// use burn_tensor::{Tensor, Shape, s};
1293    ///
1294    /// fn example<B: Backend>() {
1295    ///     let device = B::Device::default();
1296    ///
1297    ///     // Single dimension slicing - no brackets needed!
1298    ///     let tensor = Tensor::<B, 1, burn_tensor::Int>::arange(0..10, &device);
1299    ///     let slice = tensor.clone().slice(2..8);  // Simple range
1300    ///     assert_eq!(slice.into_data().to_vec::<i32>().unwrap(), vec![2, 3, 4, 5, 6, 7]);
1301    ///
1302    ///     // Using s! macro for single dimension with step
1303    ///     let slice = tensor.clone().slice(s![0..10;2]);  // Every 2nd element
1304    ///     assert_eq!(slice.into_data().to_vec::<i32>().unwrap(), vec![0, 2, 4, 6, 8]);
1305    ///
1306    ///     // Reverse a dimension with negative step
1307    ///     let slice = tensor.slice(s![..;-1]);  // Reverse entire tensor
1308    ///     assert_eq!(slice.into_data().to_vec::<i32>().unwrap(), vec![9, 8, 7, 6, 5, 4, 3, 2, 1, 0]);
1309    ///
1310    ///     // Multi-dimensional slicing
1311    ///     let tensor = Tensor::<B, 2>::ones(Shape::new([4, 6]), &device);
1312    ///
1313    ///     // Array syntax for simple ranges
1314    ///     let slice = tensor.clone().slice([1..3, 2..5]);
1315    ///     assert_eq!(slice.dims(), [2, 3]);
1316    ///
1317    ///     // Advanced multi-dimensional with s! macro
1318    ///     let slice = tensor.clone().slice(s![0..4;2, ..;-1]);  // Every 2nd row, reverse columns
1319    ///     assert_eq!(slice.dims(), [2, 6]);
1320    ///
1321    ///     // Complex 3D example with mixed slice types
1322    ///     let tensor = Tensor::<B, 3>::ones(Shape::new([4, 6, 8]), &device);
1323    ///     let slice = tensor.slice(s![1..3, ..;2, -3..]);  // Rows 1-2, every 2nd col, last 3 depth
1324    ///     assert_eq!(slice.dims(), [2, 3, 3]);
1325    ///
1326    ///     // Using negative indices
1327    ///     let tensor = Tensor::<B, 2>::ones(Shape::new([4, 6]), &device);
1328    ///     let slice = tensor.slice(s![-2.., ..-1]);  // Last 2 rows, all but last column
1329    ///     assert_eq!(slice.dims(), [2, 5]);
1330    /// }
1331    /// ```
1332    ///
1333    /// # See Also
1334    ///
1335    /// - [`s!`] - The recommended macro for creating complex slice specifications
1336    /// - [`slice_assign`](Self::slice_assign) - Assign values to a slice
1337    /// - [`slice_fill`](Self::slice_fill) - Fill a slice with a constant value
1338    /// - [`slice_dim`](Self::slice_dim) - Slice a single dimension
1339    ///
1340    /// [`s!`]: crate::s!
1341    pub fn slice<S>(self, slices: S) -> Self
1342    where
1343        S: SliceArg,
1344    {
1345        let shape = self.shape();
1346        let slices = slices.into_slices(&shape);
1347
1348        // Validate slices
1349        check!(TensorCheck::slice::<D>(&shape, &slices));
1350
1351        // Calculate output shape and check for empty slices
1352        let mut output_dims = shape.clone();
1353        for (dim, slice) in slices.iter().enumerate() {
1354            output_dims[dim] = slice.output_size(shape[dim]);
1355        }
1356
1357        // Return empty tensor if any dimension is 0 (empty slice)
1358        if output_dims.contains(&0) {
1359            return Self::empty(output_dims, &self.device());
1360        }
1361        Self::new(K::slice(self.primitive, &slices))
1362    }
1363
1364    /// Assigns values to a slice of the tensor and returns the updated tensor.
1365    ///
1366    /// This method supports advanced slicing with steps, including negative steps for reverse
1367    /// assignment. Like `slice`, it accepts both single slices and arrays, with the [`s!`] macro
1368    /// providing powerful syntax for complex patterns.
1369    ///
1370    /// # Arguments
1371    ///
1372    /// * `slices` - Slice specification (same format as `slice` method)
1373    /// * `values` - Tensor with values to assign (must match slice dimensions)
1374    ///
1375    /// # Panics
1376    ///
1377    /// - If slices exceed tensor dimensions
1378    /// - If values dimensions don't match the selected slice shape
1379    /// - If a step is zero
1380    ///
1381    /// # Examples
1382    ///
1383    /// ```rust
1384    /// use burn_tensor::backend::Backend;
1385    /// use burn_tensor::{Tensor, s};
1386    ///
1387    /// fn example<B: Backend>() {
1388    ///     let device = B::Device::default();
1389    ///
1390    ///     // Simple assignment to a sub-region
1391    ///     let mut tensor = Tensor::<B, 2>::zeros([4, 6], &device);
1392    ///     let values = Tensor::<B, 2>::ones([2, 3], &device);
1393    ///     tensor = tensor.slice_assign([1..3, 2..5], values);
1394    ///     // Now tensor[1..3, 2..5] contains ones
1395    ///
1396    ///     // Single dimension assignment with step
1397    ///     let mut tensor = Tensor::<B, 1>::zeros([10], &device);
1398    ///     let values = Tensor::<B, 1>::ones([5], &device);
1399    ///     tensor = tensor.slice_assign(s![0..10;2], values);
1400    ///     // Now every 2nd element is 1: [1, 0, 1, 0, 1, 0, 1, 0, 1, 0]
1401    ///
1402    ///     // Reverse assignment with negative step
1403    ///     let mut tensor = Tensor::<B, 1>::from_data([0.0, 1.0, 2.0, 3.0, 4.0], &device);
1404    ///     let values = Tensor::<B, 1>::from_data([10.0, 11.0, 12.0, 13.0, 14.0], &device);
1405    ///     tensor = tensor.slice_assign(s![..;-1], values);
1406    ///     // Assigns in reverse: [14, 13, 12, 11, 10]
1407    ///
1408    ///     // Complex multi-dimensional assignment
1409    ///     let mut tensor = Tensor::<B, 3>::zeros([4, 6, 8], &device);
1410    ///     let values = Tensor::<B, 3>::ones([2, 3, 3], &device);
1411    ///     tensor = tensor.slice_assign(s![0..4;2, ..;2, -3..], values);
1412    ///     // Assigns to every 2nd row, every 2nd column, last 3 in depth
1413    ///
1414    ///     // Mixed syntax example
1415    ///     let mut tensor = Tensor::<B, 2>::zeros([8, 8], &device);
1416    ///     let pattern = Tensor::<B, 2>::ones([4, 4], &device);
1417    ///     tensor = tensor.slice_assign(s![..;2, ..;2], pattern);
1418    ///     // Creates a checkerboard pattern with ones
1419    /// }
1420    /// ```
1421    ///
1422    /// # See Also
1423    ///
1424    /// - [`s!`] - The recommended macro for creating complex slice specifications
1425    /// - [`slice`](Self::slice) - Extract a slice from a tensor
1426    /// - [`slice_fill`](Self::slice_fill) - Fill a slice with a constant value
1427    ///
1428    /// [`s!`]: crate::s!
1429    pub fn slice_assign<S>(self, slices: S, values: Self) -> Self
1430    where
1431        S: SliceArg,
1432    {
1433        let shape = self.shape();
1434        let slices = slices.into_slices(&shape);
1435
1436        // Check if any slice produces 0 elements (empty assignment).
1437        // Empty assignments are no-ops and would cause issues in backend implementations.
1438        let is_empty_assignment = slices
1439            .iter()
1440            .enumerate()
1441            .any(|(i, slice)| slice.output_size(shape[i]) == 0);
1442
1443        if is_empty_assignment {
1444            return self;
1445        }
1446
1447        check!(TensorCheck::slice_assign::<D>(
1448            &shape,
1449            &values.shape(),
1450            &slices
1451        ));
1452
1453        Self::new(K::slice_assign(self.primitive, &slices, values.primitive))
1454    }
1455
1456    /// Fills a slice of the tensor with a constant value and returns the updated tensor.
1457    ///
1458    /// Like other slice methods, accepts both single slices and arrays. However, this method
1459    /// currently **does not support stepped slicing** - use [`slice_assign`](Self::slice_assign)
1460    /// with a constant tensor for stepped patterns.
1461    ///
1462    /// # Arguments
1463    ///
1464    /// * `slices` - Slice specification (same format as `slice` method, but no steps)
1465    /// * `value` - The value to fill the slice with
1466    ///
1467    /// # Panics
1468    ///
1469    /// - If slices exceed tensor dimensions
1470    /// - If any slice has a step != 1 (not yet supported)
1471    ///
1472    /// # Examples
1473    ///
1474    /// ```rust
1475    /// use burn_tensor::backend::Backend;
1476    /// use burn_tensor::{Tensor, s};
1477    ///
1478    /// fn example<B: Backend>() {
1479    ///     let device = B::Device::default();
1480    ///
1481    ///     // Simple fill for a single dimension
1482    ///     let mut tensor = Tensor::<B, 1>::zeros([10], &device);
1483    ///     tensor = tensor.slice_fill(2..5, 1.0);
1484    ///     // Now tensor is [0, 0, 1, 1, 1, 0, 0, 0, 0, 0]
1485    ///
1486    ///     // Multi-dimensional fill
1487    ///     let mut tensor = Tensor::<B, 2>::zeros([4, 6], &device);
1488    ///     tensor = tensor.slice_fill([1..3, 2..5], -1.0);
1489    ///     // Fills the rectangle at rows 1-2, columns 2-4 with -1
1490    ///
1491    ///     // Using negative indices
1492    ///     let mut tensor = Tensor::<B, 1>::zeros([10], &device);
1493    ///     tensor = tensor.slice_fill(-3.., 2.0);
1494    ///     // Fills the last 3 elements with 2.0
1495    ///
1496    ///     // Complex multi-dimensional example
1497    ///     let mut tensor = Tensor::<B, 3>::ones([4, 6, 8], &device);
1498    ///     tensor = tensor.slice_fill(s![1..3, .., -2..], 0.0);
1499    ///     // Sets rows 1-2, all columns, last 2 in depth to 0
1500    ///
1501    ///     // Stepped slicing is supported
1502    ///     let mut tensor = Tensor::<B, 1>::zeros([10], &device);
1503    ///     tensor = tensor.slice_fill(s![0..10;2], 1.0);
1504    ///     // Now every 2nd element is 1: [1, 0, 1, 0, 1, 0, 1, 0, 1, 0]
1505    /// }
1506    /// ```
1507    ///
1508    /// # See Also
1509    ///
1510    /// - [`s!`] - The macro for creating slice specifications with steps
1511    /// - [`slice`](Self::slice) - Extract a slice from a tensor
1512    /// - [`slice_assign`](Self::slice_assign) - Assign tensor values to a slice
1513    ///
1514    /// [`s!`]: crate::s!
1515    pub fn slice_fill<S, E: ElementConversion>(self, slices: S, value: E) -> Self
1516    where
1517        S: SliceArg,
1518    {
1519        let shape = self.shape();
1520        let slices = slices.into_slices(&shape);
1521
1522        check!(TensorCheck::slice::<D>(&shape, &slices));
1523
1524        let slice_shape = shape.slice(&slices).unwrap();
1525        let value = Tensor::<B, 1, K>::from_data_dtype(
1526            [value.elem::<K::Elem>()],
1527            &self.device(),
1528            self.dtype(),
1529        );
1530        let value = value.expand(slice_shape);
1531        self.slice_assign(&slices, value)
1532    }
1533
1534    /// Returns a new tensor with the specified dimension sliced.
1535    ///
1536    /// # Arguments
1537    ///
1538    /// * `dim`: The dimension to slice.
1539    /// * `slice`: The slice specification for the dimension. Can be a range (e.g., `2..5`),
1540    ///   slice with step (via `s!` macro, e.g., `s![0..10;2]`), or any type that implements `Into<Slice>`.
1541    ///
1542    /// # Returns
1543    ///
1544    /// A new tensor with the specified dimension sliced.
1545    ///
1546    /// # Panics
1547    ///
1548    /// If the slice is out of bounds for the specified dimension.
1549    ///
1550    /// # Examples
1551    ///
1552    /// ```rust
1553    /// # use burn_tensor::{Tensor, s};
1554    /// # use burn_tensor::backend::Backend;
1555    /// #
1556    /// # fn example<B: Backend>() {
1557    /// #     let device = B::Device::default();
1558    ///     let tensor = Tensor::<B, 3>::zeros([3, 4, 5], &device);
1559    ///
1560    ///     // Simple range slicing
1561    ///     let sliced = tensor.clone().slice_dim(1, 1..3);
1562    ///     assert_eq!(sliced.shape().as_slice(), [3, 2, 5]);
1563    ///
1564    ///     // Slicing with step - take every 2nd element
1565    ///     let sliced = tensor.clone().slice_dim(2, s![0..5;2]);
1566    ///     assert_eq!(sliced.shape().as_slice(), [3, 4, 3]); // Takes indices 0, 2, 4
1567    ///
1568    ///     // Reverse slicing with negative step
1569    ///     let sliced = tensor.clone().slice_dim(1, s![..;-1]);
1570    ///     assert_eq!(sliced.shape().as_slice(), [3, 4, 5]); // Reverses dimension 1
1571    ///
1572    ///     // Select from index 2 with step 3
1573    ///     let sliced = tensor.clone().slice_dim(0, s![2..;3]);
1574    ///     assert_eq!(sliced.shape().as_slice(), [1, 4, 5]); // Takes only index 2
1575    ///
1576    ///     // Select single index (reduces dimension to size 1)
1577    ///     let sliced = tensor.slice_dim(0, 1);
1578    ///     assert_eq!(sliced.shape().as_slice(), [1, 4, 5]);
1579    /// # }
1580    /// ```
1581    ///
1582    /// # See Also
1583    ///
1584    /// - [`slice`](Self::slice) - Slice multiple dimensions simultaneously
1585    /// - [`s!`] - The macro for creating complex slice specifications
1586    ///
1587    /// [`s!`]: crate::s!
1588    pub fn slice_dim<S>(self, dim: usize, slice: S) -> Self
1589    where
1590        S: Into<Slice>,
1591    {
1592        check!(TensorCheck::check_dim::<D>(dim));
1593        let slice: Slice = slice.into();
1594
1595        let mut slices = vec![Slice::full(); D];
1596        slices[dim] = slice;
1597
1598        self.slice(&slices)
1599    }
1600
1601    /// Returns the device of the current tensor.
1602    pub fn device(&self) -> B::Device {
1603        K::device(&self.primitive)
1604    }
1605
1606    /// Move the tensor to the given device.
1607    pub fn to_device(self, device: &B::Device) -> Self {
1608        Self::new(K::to_device(self.primitive, device))
1609    }
1610
1611    /// Select tensor elements along the given dimension corresponding to the given indices.
1612    ///
1613    /// # Arguments
1614    ///
1615    /// * `dim` - The dimension to select from. Supports negative indexing.
1616    /// * `indices` - The indices of the elements to select.
1617    ///
1618    /// # Example
1619    ///
1620    /// ```rust
1621    /// use burn_tensor::backend::Backend;
1622    /// use burn_tensor::{Tensor, Int};
1623    ///
1624    /// fn example<B: Backend>() {
1625    ///   let device = B::Device::default();
1626    ///   let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [4.0, 5.0, 6.0]], &device);
1627    ///   let indices = Tensor::<B, 1, Int>::from_data([0], &device);
1628    ///   let tensor = tensor.select(0, indices);
1629    ///   println!("{tensor}");
1630    ///   //  [[1.0, -2.0, 3.0]]
1631    /// }
1632    /// ```
1633    pub fn select(self, dim: impl AsIndex, indices: Tensor<B, 1, Int>) -> Self {
1634        let dim = dim.expect_dim_index(D);
1635        check!(TensorCheck::select::<D>(dim));
1636        Self::new(K::select(self.primitive, dim, indices.primitive))
1637    }
1638
1639    /// Assign the selected elements along the given dimension corresponding to the given indices
1640    /// from the value tensor to the original tensor using sum reduction.
1641    ///
1642    /// # Note
1643    /// For booleans, the sum operator is logical or.
1644    ///
1645    /// # Arguments
1646    ///
1647    /// * `dim` - The dimension along which to select. Supports negative indexing.
1648    /// * `indices` - The indices to select from the tensor.
1649    /// * `values` - The values to assign to the selected indices.
1650    /// * `update` - The operation used to update the existing values at the indexed positions (e.g., add).
1651    ///
1652    /// # Example
1653    ///
1654    /// Example using a 3D tensor:
1655    ///
1656    /// `input[indices[i], j, k] += values[i, j, k]; // dim = 0`
1657    /// `input[i, indices[j], k] += values[i, j, k]; // dim = 1`
1658    /// `input[i, j, indices[k]] += values[i, j, k]; // dim = 2`
1659    /// `input[i, j, indices[k]] += values[i, j, k]; // dim = -1 (same as dim = 2)`
1660    ///
1661    /// # Warning
1662    ///
1663    /// Not all backends have runtime bound checks for the indices, so make sure they are valid.
1664    /// Otherwise, out of bounds indices could lead to unexpected results instead of panicking.
1665    pub fn select_assign(
1666        self,
1667        dim: impl AsIndex,
1668        indices: Tensor<B, 1, Int>,
1669        values: Tensor<B, D, K>,
1670        update: IndexingUpdateOp,
1671    ) -> Self {
1672        let dim = dim.expect_dim_index(D);
1673        check!(TensorCheck::select_assign::<D>(
1674            dim,
1675            &indices.shape(),
1676            &values.shape()
1677        ));
1678
1679        Self::new(K::select_assign(
1680            self.primitive,
1681            dim,
1682            indices.primitive,
1683            values.primitive,
1684            update,
1685        ))
1686    }
1687
1688    /// Update the given tensor with the value tensor where the mask is true.
1689    ///
1690    /// This is similar to [mask_fill](Tensor::mask_fill), however the value is a tensor instead of
1691    /// a scalar.
1692    ///
1693    /// # Example
1694    ///
1695    /// ```rust
1696    /// use burn_tensor::backend::Backend;
1697    /// use burn_tensor::{Tensor, Shape, Bool};
1698    ///
1699    /// fn example<B: Backend>() {
1700    ///   let device = B::Device::default();
1701    ///   let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
1702    ///   let mask = Tensor::<B, 2, Bool>::from_data([[true, false, true], [false, true, false]], &device);
1703    ///   let value = Tensor::<B, 2>::from_data([[2.0, 3.0, 4.0], [1.0, 2.0, 3.0]], &device);
1704    ///   let tensor = tensor.mask_where(mask, value);
1705    ///   println!("{tensor}");
1706    ///   // [[2.0, -2.0, 4.0], [5.0, 2.0, 6.0]]
1707    /// }
1708    /// ```
1709    pub fn mask_where(self, mask: Tensor<B, D, Bool>, value: Self) -> Self {
1710        Self::new(K::mask_where(
1711            self.primitive,
1712            mask.primitive,
1713            value.primitive,
1714        ))
1715    }
1716
1717    /// Update the given tensor with the value where the mask is true.
1718    ///
1719    /// This is similar to [mask_where](Tensor::mask_where), however the value is a scalar instead of
1720    /// a tensor.
1721    ///
1722    /// # Example
1723    ///
1724    /// ```rust
1725    /// use burn_tensor::backend::Backend;
1726    /// use burn_tensor::{Tensor, Shape, Bool};
1727    ///
1728    /// fn example<B: Backend>() {
1729    ///   let device = B::Device::default();
1730    ///   let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
1731    ///   let mask = Tensor::<B, 2, Bool>::from_data([[true, false, true], [false, true, false]], &device);
1732    ///   let tensor = tensor.mask_fill(mask, 3.0);
1733    ///   println!("{tensor}");
1734    ///   // [[3.0, -2.0, 3.0], [5.0, 3.0, 6.0]]
1735    /// }
1736    /// ```
1737    pub fn mask_fill<E: ElementConversion>(self, mask: Tensor<B, D, Bool>, value: E) -> Self {
1738        let value = Scalar::new(value, &self.dtype());
1739        Self::new(K::mask_fill(self.primitive, mask.primitive, value))
1740    }
1741
1742    /// Gather tensor elements corresponding to the given indices from the specified dim.
1743    ///
1744    /// Example using a 3D tensor:
1745    ///
1746    /// `output[i, j, k] = input[indices[i, j, k], j, k]; // dim = 0`
1747    /// `output[i, j, k] = input[i, indices[i, j, k], k]; // dim = 1`
1748    /// `output[i, j, k] = input[i, j, indices[i, j, k]]; // dim = 2`
1749    ///
1750    /// # Notes
1751    ///
1752    /// The index tensor should have the same shape as the original tensor except for the dim
1753    /// specified.
1754    ///
1755    /// # Warning
1756    /// Not all backends have runtime bound checks for the indices, so make sure the they are valid.
1757    /// Otherwise, out of bounds indices could lead to unexpected results instead of panicking.
1758    pub fn gather(self, dim: usize, indices: Tensor<B, D, Int>) -> Self {
1759        check!(TensorCheck::gather::<D>(
1760            dim,
1761            &self.shape(),
1762            &indices.shape()
1763        ));
1764
1765        Self::new(K::gather(dim, self.primitive, indices.primitive))
1766    }
1767
1768    /// Assign the gathered elements corresponding to the given indices along the specified dimension
1769    /// from the value tensor to the original tensor using sum reduction.
1770    ///
1771    /// Example using a 3D tensor:
1772    ///
1773    /// `input[indices[i, j, k], j, k] += values[i, j, k]; // dim = 0`
1774    /// `input[i, indices[i, j, k], k] += values[i, j, k]; // dim = 1`
1775    /// `input[i, j, indices[i, j, k]] += values[i, j, k]; // dim = 2`
1776    ///
1777    /// # Arguments
1778    /// * `dim` - The axis along which to scatter elements.
1779    /// * `indices` - The indices of the elements to scatter.
1780    /// * `values` - The values to scatter into the tensor.
1781    /// * `update` - The operation used to update the existing values at the indexed positions (e.g., add).
1782    ///
1783    /// # Notes
1784    ///
1785    /// The index tensor should have the same shape as the original tensor except for the specified
1786    /// dimension. The value and index tensors should have the same shape.
1787    ///
1788    /// Other references to the input tensor will not be modified by this operation.
1789    ///
1790    /// # Warning
1791    /// Not all backends have runtime bound checks for the indices, so make sure the they are valid.
1792    /// Otherwise, out of bounds indices could lead to unexpected results instead of panicking.
1793    pub fn scatter(
1794        self,
1795        dim: usize,
1796        indices: Tensor<B, D, Int>,
1797        values: Self,
1798        update: IndexingUpdateOp,
1799    ) -> Self {
1800        check!(TensorCheck::scatter::<D>(
1801            dim,
1802            &self.shape(),
1803            &indices.shape(),
1804            &values.shape()
1805        ));
1806
1807        Self::new(K::scatter(
1808            dim,
1809            self.primitive,
1810            indices.primitive,
1811            values.primitive,
1812            update,
1813        ))
1814    }
1815
1816    /// Converts the data of the current tensor.
1817    ///
1818    /// # Note
1819    ///
1820    /// For better performance, prefer using a [Transaction](crate::Transaction) when reading multiple
1821    /// tensors at once. This may improve laziness, especially if executed on a different
1822    /// thread in native environments.
1823    pub fn into_data(self) -> TensorData {
1824        self.try_into_data().expect(
1825            "Error while reading data: use `try_into_data` instead to catch the error at runtime",
1826        )
1827    }
1828
1829    /// Converts the data of the current tensor and returns any error that might have occurred since the
1830    /// last time the device was synchronized.
1831    ///
1832    /// # Note
1833    ///
1834    /// For better performance, prefer using a [Transaction](crate::Transaction) when reading multiple
1835    /// tensors at once. This may improve laziness, especially if executed on a different
1836    /// thread in native environments.
1837    pub fn try_into_data(self) -> Result<TensorData, ExecutionError> {
1838        crate::try_read_sync(self.into_data_async()).expect(
1839            "Failed to read tensor data synchronously.
1840        This can happen on platforms that don't support blocking futures like WASM.
1841        If possible, try using into_data_async instead.",
1842        )
1843    }
1844
1845    /// Converts the data of the current tensor.
1846    ///
1847    /// # Note
1848    ///
1849    /// For better performance, prefer using a [Transaction](crate::Transaction) when reading multiple
1850    /// tensors at once. This may improve laziness, especially if executed on a different
1851    /// thread in native environments.
1852    pub fn to_data(&self) -> TensorData {
1853        self.clone().into_data()
1854    }
1855
1856    /// Returns the data of the current tensor.
1857    pub async fn into_data_async(self) -> Result<TensorData, ExecutionError> {
1858        K::into_data_async(self.primitive).await
1859    }
1860
1861    /// Returns the data of the current tensor.
1862    pub async fn to_data_async(&self) -> Result<TensorData, ExecutionError> {
1863        self.clone().into_data_async().await
1864    }
1865
1866    /// Create a tensor from the given data on the given device.
1867    pub fn from_data<T>(data: T, device: &B::Device) -> Self
1868    where
1869        T: Into<TensorData>,
1870    {
1871        let data = data.into();
1872        check!(TensorCheck::creation_ops::<D>(
1873            "From Data",
1874            data.shape.as_slice()
1875        ));
1876        Self::new(K::from_data(data, device))
1877    }
1878
1879    /// Create a tensor from the given data on the given device enforcing the given data type.
1880    pub fn from_data_dtype<T>(data: T, device: &B::Device, dtype: DType) -> Self
1881    where
1882        T: Into<TensorData>,
1883    {
1884        let data = data.into();
1885        check!(TensorCheck::creation_ops::<D>(
1886            "From Data",
1887            data.shape.as_slice()
1888        ));
1889        Self::new(K::from_data_dtype(data, device, dtype))
1890    }
1891
1892    /// Repeat the tensor along the given dimension.
1893    ///
1894    /// The output tensor has the same shape, except along the given dimension.
1895    ///
1896    /// # Arguments
1897    /// - `dim`: The dimension to repeat.
1898    /// - `times`: The number of times to repeat the tensor along the given dimension in the new tensor.
1899    ///
1900    /// # Returns
1901    ///
1902    /// A new tensor with the given dimension repeated `times` times.
1903    ///
1904    /// # Example
1905    ///
1906    /// ```rust
1907    /// use burn_tensor::backend::Backend;
1908    /// use burn_tensor::Tensor;
1909    ///
1910    /// fn example<B: Backend>() {
1911    ///     let device = Default::default();
1912    ///     // Create a 2D tensor with dimensions [3, 2]
1913    ///     let tensor = Tensor::<B, 2>::from_data([[3.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
1914    ///
1915    ///     // Repeat the tensor along the dimension 0 twice.
1916    ///     // [[3.0, 4.9], [2.0, 1.9], [4.0, 5.9], [3.0, 4.9], [2.0, 1.9], [4.0, 5.9]]
1917    ///     // The resulting tensor will have dimensions [6, 2].
1918    ///     let repeated = tensor.repeat_dim(0, 2);
1919    ///     println!("{repeated}");
1920    /// }
1921    /// ```
1922    pub fn repeat_dim(self, dim: usize, times: usize) -> Self {
1923        if times > 0 {
1924            Self::new(K::repeat_dim(self.primitive, dim, times))
1925        } else {
1926            let shape = self.shape().repeat(dim, times).unwrap();
1927            Self::empty(shape, &self.device())
1928        }
1929    }
1930
1931    /// Repeat the tensor along the given dimensions.
1932    /// # Arguments
1933    /// - `sizes`: Borrowed slice of the number of times to repeat each dimension.
1934    ///
1935    /// # Returns
1936    ///
1937    /// A new tensor with the given dimensions repeated `times` times.
1938    ///
1939    /// # Panics
1940    ///
1941    /// If `sizes` contains more elements than the number of dimensions.
1942    ///
1943    /// # Example
1944    ///
1945    /// ```rust
1946    ///
1947    /// use burn_tensor::backend::Backend;
1948    /// use burn_tensor::Tensor;
1949    ///
1950    /// fn example<B: Backend>() {
1951    ///     let device = Default::default();
1952    ///     // Create a 2D tensor with dimensions [3, 2]
1953    ///     let tensor = Tensor::<B, 2>::from_data([[3.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
1954    ///
1955    ///     // Repeat the tensor along the dimension 0 twice and the dimension 0 once.
1956    ///     // [[3.0, 4.9], [2.0, 1.9], [4.0, 5.9], [3.0, 4.9], [2.0, 1.9], [4.0, 5.9]]
1957    ///     // The resulting tensor will have dimensions [6, 2].
1958    ///     let repeated = tensor.repeat(&[2, 1]);
1959    /// }
1960    /// ```
1961    pub fn repeat(self, sizes: &[usize]) -> Self {
1962        if sizes.contains(&0) {
1963            let mut shape = self.shape();
1964            for (dim, &times) in sizes.iter().enumerate() {
1965                shape = shape.repeat(dim, times).unwrap();
1966            }
1967
1968            return Self::empty(shape, &self.device());
1969        }
1970
1971        let mut tensor = self;
1972        for (dim, &times) in sizes.iter().enumerate() {
1973            if times > 1 {
1974                tensor = tensor.repeat_dim(dim, times);
1975            }
1976        }
1977        tensor
1978    }
1979
1980    /// Applies element-wise equal comparison.
1981    ///
1982    /// # Returns
1983    /// A boolean tensor that is `true` where input is equal to `other` and `false` elsewhere.
1984    ///
1985    /// # Panics
1986    ///
1987    /// If the two tensors don't have the same shape.
1988    ///
1989    /// # Example
1990    ///
1991    /// ```rust
1992    /// use burn_tensor::backend::Backend;
1993    /// use burn_tensor::Tensor;
1994    ///
1995    /// fn example<B: Backend>() {
1996    ///     let device = Default::default();
1997    ///     let t1 = Tensor::<B, 2>::from_data([[2.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
1998    ///     let t2 = Tensor::<B, 2>::from_data([[3.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
1999    ///     // Compare the elements of the two 2D tensors with dimensions [3, 2].
2000    ///     // [[false, true], [true, true], [true, true]]
2001    ///     let equal = t1.equal(t2);
2002    ///     println!("{equal}");
2003    /// }
2004    /// ```
2005    pub fn equal(self, other: Self) -> Tensor<B, D, Bool> {
2006        check!(TensorCheck::binary_ops_ew("Equal", &self, &other));
2007        Tensor::new(K::equal(self.primitive, other.primitive))
2008    }
2009
2010    /// Applies element-wise non-equality comparison.
2011    ///
2012    /// # Returns
2013    /// A boolean tensor that is `true` where input is not equal to `other` and `false` elsewhere.
2014    ///
2015    /// # Panics
2016    ///
2017    /// If the two tensors don't have the same shape.
2018    ///
2019    /// # Example
2020    ///
2021    /// ```rust
2022    /// use burn_tensor::backend::Backend;
2023    /// use burn_tensor::Tensor;
2024    ///
2025    /// fn example<B: Backend>() {
2026    ///     let device = Default::default();
2027    ///     let t1 = Tensor::<B, 2>::from_data([[2.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
2028    ///     let t2 = Tensor::<B, 2>::from_data([[3.0, 4.9], [2.0, 1.9], [4.0, 5.9]], &device);
2029    ///     // Compare the elements of the two 2D tensors for inequality.
2030    ///     // [[true, false], [false, false], [false, false]]
2031    ///     let not_equal = t1.not_equal(t2);
2032    ///     println!("{not_equal}");
2033    /// }
2034    /// ```
2035    pub fn not_equal(self, other: Self) -> Tensor<B, D, Bool> {
2036        check!(TensorCheck::binary_ops_ew("NotEqual", &self, &other));
2037        Tensor::new(K::not_equal(self.primitive, other.primitive))
2038    }
2039
2040    /// Applies element wise equal comparison and returns a boolean tensor.
2041    ///
2042    /// # Arguments
2043    ///
2044    /// * `other` - The element to compare.
2045    ///
2046    /// # Example
2047    ///
2048    /// ```rust
2049    /// use burn_tensor::backend::Backend;
2050    /// use burn_tensor::{Tensor, Shape};
2051    ///
2052    /// fn example<B: Backend>() {
2053    ///    let device = B::Device::default();
2054    ///    let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
2055    ///    let tensor = tensor.equal_elem(3.0);
2056    ///    println!("{tensor}");
2057    ///    // [[false, false, true], [false, false, false]]
2058    /// }
2059    /// ```
2060    pub fn equal_elem<E: Element>(self, other: E) -> Tensor<B, D, Bool> {
2061        let other = Scalar::new(other, &self.dtype());
2062        Tensor::new(K::equal_elem(self.primitive, other))
2063    }
2064
2065    /// Applies element wise non-equality comparison and returns a boolean tensor.
2066    ///
2067    /// # Arguments
2068    ///
2069    /// * `other` - The element to compare.
2070    ///
2071    /// # Example
2072    ///
2073    /// ```rust
2074    /// use burn_tensor::backend::Backend;
2075    /// use burn_tensor::{Tensor, Shape};
2076    ///
2077    /// fn example<B: Backend>() {
2078    ///    let device = B::Device::default();
2079    ///    let tensor = Tensor::<B, 2>::from_data([[1.0, -2.0, 3.0], [5.0, 9.0, 6.0]], &device);
2080    ///    let tensor = tensor.not_equal_elem(3.0);
2081    ///    println!("{tensor}");
2082    ///    // [[true, true, false], [true, true, true]]
2083    /// }
2084    /// ```
2085    pub fn not_equal_elem<E: Element>(self, other: E) -> Tensor<B, D, Bool> {
2086        let other = Scalar::new(other, &self.dtype());
2087        Tensor::new(K::not_equal_elem(self.primitive, other))
2088    }
2089
2090    /// Concatenates all tensors into a new one along the given dimension.
2091    ///
2092    /// # Panics
2093    ///
2094    /// - If `dim` is higher than the rank.
2095    /// - If `tensors` is an empty vector.
2096    /// - If all tensors don't have the same shape (the dimension `dim` is ignored).
2097    ///
2098    /// # Example
2099    ///
2100    /// ```rust
2101    /// use burn_tensor::backend::Backend;
2102    /// use burn_tensor::Tensor;
2103    ///
2104    /// fn example<B: Backend>() {
2105    ///     let device = Default::default();
2106    ///     let t1 = Tensor::<B, 2>::from_data([[3.0, 4.9, 2.0, 1.0], [2.0, 1.9, 3.0, 1.0]], &device);
2107    ///     let t2 = Tensor::<B, 2>::from_data([[4.0, 5.9, 8.0], [1.4, 5.8, 6.0]], &device);
2108    ///
2109    ///     // Concatenate the two tensors with shapes [2, 4] and [2, 3] along the dimension 1.
2110    ///     // [[3.0, 4.9, 2.0, 1.0, 4.0, 5.9, 8.0], [2.0, 1.9, 3.0, 1.0, 1.4, 5.8, 6.0]]
2111    ///     // The resulting tensor will have shape [2, 7].
2112    ///     let concat = Tensor::cat(vec![t1, t2], 1);
2113    ///     println!("{concat}");
2114    /// }
2115    /// ```
2116    pub fn cat(tensors: Vec<Self>, dim: usize) -> Self {
2117        check!(TensorCheck::cat(&tensors, dim));
2118
2119        // Filter out tensors with size 0 along the concatenation dimension.
2120        // Empty tensors don't contribute to the output and would cause issues
2121        // in backend implementations (e.g., division by zero in slice_assign).
2122        // Safety: TensorCheck::cat ensures tensors is non-empty
2123        let first_tensor = tensors.first().unwrap();
2124        let device = first_tensor.device();
2125        let mut shape = first_tensor.shape();
2126
2127        let non_empty_primitives: Vec<_> = tensors
2128            .into_iter()
2129            .filter(|t| t.shape()[dim] > 0)
2130            .map(|t| t.primitive)
2131            .collect();
2132
2133        // If all tensors were empty, return an empty tensor with size 0 on concat dim
2134        if non_empty_primitives.is_empty() {
2135            shape[dim] = 0;
2136            return Self::empty(shape, &device);
2137        }
2138
2139        Self::new(K::cat(non_empty_primitives, dim))
2140    }
2141
2142    /// Concatenates all tensors into a new one along a new dimension.
2143    ///
2144    /// # Panics
2145    ///
2146    /// - If all tensors don't have the same shape.
2147    /// - If given dimension is not with range of 0..D2
2148    ///
2149    /// # Example
2150    ///
2151    /// ```rust
2152    /// use burn_tensor::backend::Backend;
2153    /// use burn_tensor::Tensor;
2154    ///
2155    /// fn example<B: Backend>() {
2156    ///     let device = Default::default();
2157    ///     let t1 = Tensor::<B, 2>::from_data([[3.0, 4.9, 2.0], [2.0, 1.9, 3.0]], &device);
2158    ///     let t2 = Tensor::<B, 2>::from_data([[4.0, 5.9, 8.0], [1.4, 5.8, 6.0]], &device);
2159    ///     let t3 = Tensor::<B, 2>::from_data([[4.0, 5.9, 8.0], [1.4, 5.8, 6.0]], &device);
2160    ///
2161    ///     // Concatenate the three tensors with shape [2, 3] along a new dimension, 0.
2162    ///     // [[[3.0, 4.9, 2.0], [2.0, 1.9, 3.0]],
2163    ///     //  [[4.0, 5.9, 8.0], [1.4, 5.8, 6.0]],
2164    ///     //  [[4.0, 5.9, 8.0], [1.4, 5.8, 6.0]]]
2165    ///     // The resulting tensor will have shape [3, 2, 3].
2166    ///     let stacked= Tensor::stack::<3>(vec![t1, t2, t3], 0);
2167    ///     println!("{stacked}");
2168    /// }
2169    /// ```
2170    pub fn stack<const D2: usize>(tensors: Vec<Tensor<B, D, K>>, dim: usize) -> Tensor<B, D2, K> {
2171        check!(TensorCheck::stack::<B, D, K, D2>(&tensors, dim));
2172        let tensors = tensors.into_iter().map(|t| t.unsqueeze_dim(dim)).collect();
2173        Tensor::<B, D2, K>::cat(tensors, dim)
2174    }
2175
2176    /// Iterate over slices of tensors alongside a given dimension.
2177    ///
2178    /// # Panics
2179    ///
2180    /// If given dimension is greater than or equal to tensor rank.
2181    ///
2182    /// # Returns
2183    ///
2184    /// A tensor iterator.
2185    ///
2186    /// # Example
2187    ///
2188    /// ```rust
2189    /// use burn_tensor::backend::Backend;
2190    /// use burn_tensor::Tensor;
2191    /// fn example<B: Backend>() {
2192    ///   let device = Default::default();
2193    ///   let tensor = Tensor::<B,2>::from_data([[3.0, 4.9, 2.0], [2.0, 1.9, 3.0]], &device);
2194    ///   // Given a 2D tensor with dimensions [2, 3], iterate over slices of tensors along the dimension 0.
2195    ///   let iter = tensor.iter_dim(0);
2196    ///   for (i,tensor) in iter.enumerate() {
2197    ///     println!("Tensor {}: {}", i, tensor);
2198    ///     // Tensor 0: Tensor { data: [[3.0, 4.9, 2.0]], ... }
2199    ///     // Tensor 1: Tensor { data: [[2.0, 1.9, 3.0]], ... }
2200    ///  }
2201    /// }
2202    /// ```
2203    pub fn iter_dim(self, dim: usize) -> DimIter<B, D, K> {
2204        check!(TensorCheck::dim_ops::<D>("iter_dim", dim));
2205        DimIter::new(self, dim)
2206    }
2207
2208    /// Returns a new tensor with the given dimension narrowed to the given range.
2209    ///
2210    /// # Panics
2211    ///
2212    /// - If the dimension is greater than the number of dimensions of the tensor.
2213    /// - If the given range exceeds the number of elements on the given dimension.
2214    ///
2215    /// # Returns
2216    ///
2217    /// A new tensor with the given dimension narrowed to the given range.
2218    ///
2219    /// # Example
2220    ///
2221    /// ```rust
2222    /// use burn_tensor::backend::Backend;
2223    /// use burn_tensor::Tensor;
2224    ///
2225    /// fn example<B: Backend>() {
2226    ///     let device = Default::default();
2227    ///     // Create a 2D tensor with dimensions [4, 3]
2228    ///     let tensor = Tensor::<B, 2>::from_data(
2229    ///         [
2230    ///             [3.0, 4.9, 2.0],
2231    ///             [2.0, 1.9, 3.0],
2232    ///             [6.0, 1.5, 7.0],
2233    ///             [3.0, 4.9, 9.0],
2234    ///         ],
2235    ///         &device,
2236    ///     );
2237    ///     // Narrow the tensor along the dimension 0, keeping 3 elements starting from index 1.
2238    ///     // [[2.0, 1.9, 3.0], [6.0, 1.5, 7.0], [3.0, 4.9, 9.0]]
2239    ///     // The resulting tensor will have dimensions [3, 3].
2240    ///     let narrowed = tensor.narrow(0, 1, 3);
2241    ///     println!("{narrowed}");
2242    /// }
2243    /// ```
2244    pub fn narrow(self, dim: usize, start: usize, length: usize) -> Self {
2245        check!(TensorCheck::dim_ops::<D>("narrow", dim));
2246        check!(TensorCheck::narrow(&self, dim, start, length));
2247        let dims = self.dims();
2248
2249        let ranges: [Range<usize>; D] = dims
2250            .iter()
2251            .enumerate()
2252            .map(|(i, d)| {
2253                if i == dim {
2254                    start..(start + length)
2255                } else {
2256                    0..*d
2257                }
2258            })
2259            .collect::<Vec<_>>()
2260            .try_into()
2261            .unwrap();
2262
2263        Self::slice(self, ranges)
2264    }
2265
2266    /// Attempts to split the tensor into a specified number of chunks along a given dimension.
2267    /// May return less chunks than requested if the tensor size is not divisible by the number of chunks.
2268    ///
2269    /// When the given dimension is evenly divisible by the number of chunks, the chunks will be of equal size.
2270    /// Otherwise all chunks will be of equal size except for the last one.
2271    ///
2272    /// # Panics
2273    ///
2274    /// If the dimension is greater than the number of dimensions of the tensor.
2275    ///
2276    /// # Returns
2277    /// A vector of tensors.
2278    ///
2279    /// # Example
2280    ///
2281    /// ```rust
2282    /// use burn_tensor::backend::Backend;
2283    /// use burn_tensor::Tensor;
2284    ///
2285    /// fn example<B: Backend>() {
2286    ///     let device = Default::default();
2287    ///     // Create a 2D tensor with dimensions [4, 3]
2288    ///     let tensor = Tensor::<B, 2>::from_data(
2289    ///         [
2290    ///             [3.0, 4.9, 2.0],
2291    ///             [2.0, 1.9, 3.0],
2292    ///             [6.0, 1.5, 7.0],
2293    ///             [3.0, 4.9, 9.0],
2294    ///         ],
2295    ///         &device,
2296    ///     );
2297    ///     // Split the tensor along the dimension 1 into 2 chunks.
2298    ///     // The first chuck will have shape [4, 2]:
2299    ///     // [[3.0, 4.9], [2.0, 1.9], [6.0, 1.5], [3.0, 4.9]]
2300    ///     // The second chunk will have shape [4, 1]:
2301    ///     // [[2.0], [3.0], [7.0], [9.0]]
2302    ///     let chunks = tensor.chunk(2, 1);
2303    ///     println!("{chunks:?}");
2304    /// }
2305    /// ```
2306    pub fn chunk(self, chunks: usize, dim: usize) -> Vec<Self> {
2307        check!(TensorCheck::dim_ops::<D>("chunk", dim));
2308        let size = self.shape()[dim];
2309        if size < chunks {
2310            return (0..size)
2311                .map(|i| Self::narrow(self.clone(), dim, i, 1))
2312                .collect();
2313        }
2314
2315        let mut tensors = Vec::with_capacity(chunks);
2316        let mut sum_chunk_size = 0;
2317        if size.is_multiple_of(chunks) {
2318            let chunk_size = size / chunks;
2319            for _ in 0..chunks {
2320                tensors.push(Self::narrow(self.clone(), dim, sum_chunk_size, chunk_size));
2321                sum_chunk_size += chunk_size;
2322            }
2323        } else {
2324            let chunk_size = (size / chunks) + 1; // assumes not divisible
2325            for _ in 0..chunks - 1 {
2326                tensors.push(Self::narrow(self.clone(), dim, sum_chunk_size, chunk_size));
2327                sum_chunk_size += chunk_size;
2328            }
2329            let remainder = size % chunk_size;
2330            tensors.push(Self::narrow(self.clone(), dim, sum_chunk_size, remainder));
2331        }
2332
2333        tensors
2334    }
2335
2336    /// Splits the tensor into chunks of a specified size along a given dimension.
2337    /// Each chunk is a view of the original tensor.
2338    ///
2339    /// If the tensor size along the given dimension is not divisible by `split_size`,
2340    /// then the last chunk will be smaller.
2341    ///
2342    /// # Panics
2343    ///
2344    /// If the specified dimension to split along is greater than the number of dimensions of the tensor.
2345    ///
2346    /// # Returns
2347    ///
2348    /// A vector of tensors.
2349    ///
2350    /// # Example
2351    /// ```rust
2352    /// use burn_tensor::backend::Backend;
2353    /// use burn_tensor::Tensor;
2354    ///
2355    /// fn example<B: Backend>() {
2356    ///     let device = Default::default();
2357    ///     // Create a 1D tensor with 5 elements
2358    ///     let tensor = Tensor::<B, 1>::from_data([0.0, 1.0, 2.0, 3.0, 4.0], &device);
2359    ///     // Split the tensor into chunks of size 2 along dimension 0
2360    ///     let chunks = tensor.split(2, 0);
2361    ///     // The result is a vector of tensors:
2362    ///     // [Tensor([0.0, 1.0]), Tensor([2.0, 3.0]), Tensor([4.0])]
2363    ///     println!("{:?}", chunks);
2364    /// }
2365    /// ```
2366    pub fn split(self, split_size: usize, dim: usize) -> Vec<Self> {
2367        check!(TensorCheck::split::<D>(&self.shape(), split_size, dim));
2368        let size = self.shape()[dim];
2369        let mut tensors = Vec::new();
2370
2371        let mut start = 0;
2372        while start < size {
2373            let length = usize::min(split_size, size - start);
2374            tensors.push(Self::narrow(self.clone(), dim, start, length));
2375            start += length;
2376        }
2377
2378        tensors
2379    }
2380
2381    /// Splits the tensor into chunks with the specified sizes along a given dimension.
2382    /// Each chunk is a view of the original tensor.
2383    ///
2384    /// The sizes of the chunks are specified in the `split_sizes` vector. The sum of the sizes
2385    /// in `split_sizes` must equal the size of the tensor along the specified dimension.
2386    ///
2387    /// # Panics
2388    ///
2389    /// If the specified dimension to split along is greater than the number of dimensions of the tensor or
2390    /// if the sum of `dim_sizes` does not equal the size of the tensor along `dim`.
2391    ///
2392    /// # Returns
2393    ///
2394    /// A vector of tensors.
2395    ///
2396    /// # Example
2397    /// ```rust
2398    /// use burn_tensor::backend::Backend;
2399    /// use burn_tensor::Tensor;
2400    ///
2401    /// fn example<B: Backend>() {
2402    ///     let device = Default::default();
2403    ///     // Create a 1D tensor with 5 elements
2404    ///     let tensor = Tensor::<B, 1>::from_data([0.0, 1.0, 2.0, 3.0, 4.0], &device);
2405    ///     // Split the tensor into chunks with sizes [2, 3] along dimension 0
2406    ///     let chunks = tensor.split_with_sizes(vec![2, 3], 0);
2407    ///     // The result is a vector of tensors:
2408    ///     // [Tensor([0.0, 1.0]), Tensor([2.0, 3.0, 4.0])]
2409    ///     println!("{:?}", chunks);
2410    /// }
2411    /// ```
2412    pub fn split_with_sizes(self, split_sizes: Vec<usize>, dim: usize) -> Vec<Self> {
2413        check!(TensorCheck::split_with_sizes::<D>(
2414            &self.shape(),
2415            &split_sizes,
2416            dim
2417        ));
2418        let mut tensors = Vec::new();
2419
2420        let mut start = 0;
2421        for length in split_sizes {
2422            if length == 0 {
2423                continue;
2424            }
2425            tensors.push(Self::narrow(self.clone(), dim, start, length));
2426            start += length;
2427        }
2428
2429        tensors
2430    }
2431
2432    /// Tests if any element in the `tensor` evaluates to True.
2433    ///
2434    /// # Arguments
2435    ///
2436    /// * `tensor` - The tensor to test. All input tensor types (Float, Int, Bool) are supported.
2437    ///
2438    /// # Returns
2439    ///
2440    /// A boolean tensor `Tensor<B, 1, Bool>` containing a single element, True if any element in the input tensor
2441    /// evaluates to True, False otherwise.
2442    ///
2443    /// # Example
2444    ///
2445    /// ```rust
2446    /// use burn_tensor::backend::Backend;
2447    /// use burn_tensor::{Tensor, Bool};
2448    ///
2449    /// fn example<B: Backend>() {
2450    ///   let device = Default::default();
2451    ///   let tensor = Tensor::<B,2, Bool>::from_data([[true,false,true],[false,true,false]], &device);
2452    ///   let tensor_two = Tensor::<B,2, Bool>::from_data([[false,false,false],[false,false,false]], &device);
2453    ///
2454    ///   // Given a 2D tensor with dimensions [2, 3], test if any element in the tensor evaluates to True.
2455    ///   let any_tensor = tensor.any();
2456    ///   println!("{}", any_tensor);
2457    ///   // Tensor { data: [true], ... }
2458    ///
2459    ///   // Given a 2D tensor with dimensions [2, 3], test if any element in the tensor evaluates to True.
2460    ///   let any_tensor_two = tensor_two.any();
2461    ///   println!("{}", any_tensor_two);
2462    ///   // Tensor { data: [false], ... }
2463    /// }
2464    /// ```
2465    pub fn any(self) -> Tensor<B, 1, Bool> {
2466        Tensor::new(K::any(self.primitive))
2467    }
2468
2469    /// Tests if any element in the `tensor` evaluates to True along a given dimension `dim`.
2470    ///
2471    /// # Arguments
2472    ///
2473    /// * `tensor` - The tensor to test. All input tensor types (Float, Int, Bool) are supported.
2474    /// * `dim` - The axis along which to test.
2475    ///
2476    /// # Returns
2477    ///
2478    /// A boolean tensor `Tensor<B, D, Bool>` with the same shape as input `tensor`, except in the `dim` axis
2479    /// where the size is 1. The elem in the `dim` axis is True if any element along this dim in the input
2480    /// evaluates to True, False otherwise.
2481    ///
2482    /// # Example
2483    ///
2484    /// ```rust
2485    /// use burn_tensor::backend::Backend;
2486    /// use burn_tensor::{Tensor, Bool};
2487    ///
2488    /// fn example<B: Backend>() {
2489    ///     let device = Default::default();
2490    ///     let tensor =
2491    ///         Tensor::<B, 2, Bool>::from_data([[true, false, false], [false, true, false]], &device);
2492    ///     // Check if any element in the tensor evaluates to True along the dimension 1.
2493    ///     // [[true], [true]],
2494    ///     let any_dim = tensor.clone().any_dim(1);
2495    ///     println!("{any_dim}");
2496    /// }
2497    /// ```
2498    pub fn any_dim(self, dim: usize) -> Tensor<B, D, Bool> {
2499        Tensor::new(K::any_dim(self.primitive, dim))
2500    }
2501
2502    /// Tests if all elements in the `tensor` evaluate to True.
2503    ///
2504    /// # Arguments
2505    ///
2506    /// * `tensor` - The tensor to test. All input tensor types (Float, Int, Bool) are supported.
2507    ///
2508    /// # Returns
2509    ///
2510    /// A boolean tensor `Tensor<B, 1, Bool>` with a single element, True if all elements in the input tensor
2511    /// evaluate to True, False otherwise.
2512    ///
2513    /// # Example
2514    ///
2515    /// ```rust
2516    /// use burn_tensor::backend::Backend;
2517    /// use burn_tensor::{Tensor, Bool};
2518    ///
2519    /// fn example<B: Backend>() {
2520    ///     let device = Default::default();
2521    ///     let tensor =
2522    ///         Tensor::<B, 2, Bool>::from_data([[true, false, true], [true, true, true]], &device);
2523    ///     // Check if all elements in the tensor evaluate to True (which is not the case).
2524    ///     // [false]
2525    ///     let all = tensor.all();
2526    ///     println!("{all}");
2527    /// }
2528    /// ```
2529    pub fn all(self) -> Tensor<B, 1, Bool> {
2530        Tensor::new(K::all(self.primitive))
2531    }
2532
2533    /// Tests if all elements in the `tensor` evaluate to True along a given dimension `dim`.
2534    ///
2535    /// # Arguments
2536    ///
2537    /// * `tensor` - The tensor to test. All input tensor types (Float, Int, Bool) are supported.
2538    /// * `dim` - The axis along which to test.
2539    ///
2540    /// # Returns
2541    ///
2542    /// A boolean tensor `Tensor<B, D, Bool>` with the same shape as input `tensor`, except in the `dim` axis
2543    /// where the size is 1. The elem in the `dim` axis is True if all elements along this dim in the input
2544    /// evaluates to True, False otherwise.
2545    ///
2546    /// # Example
2547    ///
2548    /// ```rust
2549    /// use burn_tensor::backend::Backend;
2550    /// use burn_tensor::{Tensor, Bool};
2551    ///
2552    /// fn example<B: Backend>() {
2553    ///     let device = Default::default();
2554    ///     let tensor =
2555    ///         Tensor::<B, 2, Bool>::from_data([[true, true, false], [true, true, true]], &device);
2556    ///     // Check if all elements in the tensor evaluate to True along the dimension 1.
2557    ///     // [[true, true, false]]
2558    ///     let all_dim = tensor.clone().all_dim(0);
2559    ///     println!("{all_dim}");
2560    /// }
2561    /// ```
2562    pub fn all_dim(self, dim: usize) -> Tensor<B, D, Bool> {
2563        Tensor::new(K::all_dim(self.primitive, dim))
2564    }
2565
2566    /// Convert the tensor into a scalar.
2567    ///
2568    /// # Panics
2569    ///
2570    /// - If the tensor doesn't have one element.
2571    /// - If the backend fails to read the tensor data synchronously.
2572    ///
2573    /// # Returns
2574    ///
2575    /// The scalar value of the tensor.
2576    ///
2577    /// # Example
2578    ///
2579    /// ```rust
2580    /// use burn_tensor::backend::Backend;
2581    /// use burn_tensor::Tensor;
2582    ///
2583    /// fn example<B: Backend>() {
2584    ///     let device = Default::default();
2585    ///     let tensor = Tensor::<B, 2>::from_data([[3.0]], &device);
2586    ///     // Convert the tensor with a single element into a scalar.
2587    ///     let scalar = tensor.into_scalar();
2588    ///     println!("{scalar}");
2589    /// }
2590    /// ```
2591    pub fn into_scalar(self) -> K::Elem {
2592        crate::try_read_sync(self.into_scalar_async())
2593            .expect(
2594            "Failed to read tensor data synchronously. This can happen on platforms
2595            that don't support blocking futures like WASM. Try into_scalar_async instead.",
2596            )
2597            .expect("Error while reading data: use `try_into_scalar` instead to catch the error at runtime")
2598    }
2599
2600    /// Convert the tensor into a scalar and returns any error that might have occurred since the
2601    /// last time the device was synchronized.
2602    ///
2603    /// # Panics
2604    ///
2605    /// - If the tensor doesn't have one element.
2606    /// - If the backend fails to read the tensor data synchronously.
2607    ///
2608    /// # Returns
2609    ///
2610    /// The scalar value of the tensor.
2611    pub fn try_into_scalar(self) -> Result<K::Elem, ExecutionError> {
2612        crate::try_read_sync(self.into_scalar_async()).expect(
2613            "Failed to read tensor data synchronously. This can happen on platforms
2614            that don't support blocking futures like WASM. Try into_scalar_async instead.",
2615        )
2616    }
2617
2618    /// Convert the tensor into a scalar.
2619    ///
2620    /// # Panics
2621    ///
2622    /// If the tensor doesn't have one element.
2623    pub async fn into_scalar_async(self) -> Result<K::Elem, ExecutionError> {
2624        check!(TensorCheck::into_scalar::<D>(&self.shape()));
2625
2626        Ok(self.into_data_async().await?.iter().next().unwrap())
2627    }
2628
2629    /// Broadcast the tensor to the given shape.
2630    ///
2631    /// Only singleton dimensions can be expanded to a larger size. Other dimensions must have the same size
2632    /// (which can be inferred with `-1`).
2633    ///
2634    /// # Arguments
2635    ///
2636    /// * `shape` - The shape to broadcast the tensor to.
2637    ///   Can contain -1 for dimensions that should be inferred.
2638    ///   The number of elements in the shape must be greater or equal as
2639    ///   the number of dimensions of the tensor.
2640    ///
2641    /// # Panics
2642    ///
2643    /// If the tensor cannot be broadcasted to the given shape.
2644    ///
2645    /// # Returns
2646    ///
2647    /// A new tensor with the given shape.
2648    ///
2649    /// # Example
2650    ///
2651    /// ```rust
2652    /// use burn_tensor::backend::Backend;
2653    /// use burn_tensor::Tensor;
2654    ///
2655    /// fn example<B: Backend>() {
2656    ///     let device = Default::default();
2657    ///     // Create a 2D tensor with dimensions [3, 1]
2658    ///     let tensor = Tensor::<B, 2>::from_data([[1.], [2.], [3.]], &device);
2659    ///     // Expand the tensor to a new shape [3, 4]
2660    ///     // [[1.0, 1.0, 1.0, 1.0], [2.0, 2.0, 2.0, 2.0], [3.0, 3.0, 3.0, 3.0]]
2661    ///     let expanded = tensor.expand([3, 4]);
2662    ///     println!("{}", expanded);
2663    /// }
2664    /// ```
2665    pub fn expand<const D2: usize, S: BroadcastArgs<D, D2>>(self, shape: S) -> Tensor<B, D2, K> {
2666        let shape = shape.into_shape(&self.shape());
2667        check!(TensorCheck::expand::<D, D2>(
2668            "expand",
2669            &self.shape(),
2670            &shape,
2671        ));
2672
2673        Tensor::<B, D2, K>::new(K::expand(self.primitive, shape))
2674    }
2675
2676    /// Unfold windows along a dimension.
2677    ///
2678    /// Returns a view of the tensor with all complete windows of size `size` in dimension `dim`;
2679    /// where windows are advanced by `step` at each index.
2680    ///
2681    /// The number of windows is `max(0, (shape[dim] - size).ceil_div(step))`.
2682    ///
2683    /// The new view will have the unfolded dimension replaced by two dimensions;
2684    /// one in the position of the original dimension, with size equal to the number of windows,
2685    /// and one appended to the right-most position, with size equal to `size`.
2686    ///
2687    /// # Warning
2688    ///
2689    /// For the `ndarray` backend; this is not a view but a copy
2690    /// with duplicated data.
2691    ///
2692    /// # Arguments
2693    ///
2694    /// * `dim` - the dimension to unfold.
2695    /// * `size` - the size of each unfolded window.
2696    /// * `step` - the step between each window.
2697    ///
2698    /// # Returns
2699    ///
2700    /// A tensor view with the shape ``[pre=..., windows, post=..., size]``.
2701    pub fn unfold<const D2: usize, I: AsIndex>(
2702        self,
2703        dim: I,
2704        size: usize,
2705        step: usize,
2706    ) -> Tensor<B, D2, K> {
2707        let dim = dim.expect_dim_index(D);
2708        check!(TensorCheck::unfold::<D, D2>(
2709            "unfold",
2710            &self.shape(),
2711            dim,
2712            size,
2713            step,
2714        ));
2715        Tensor::<B, D2, K>::new(K::unfold(self.primitive, dim, size, step))
2716    }
2717}
2718
2719/// Iterator given by (Tensor::iter_dim).
2720pub struct DimIter<B, const D: usize, K>
2721where
2722    B: Backend,
2723    K: BasicOps<B>,
2724{
2725    start: usize,
2726    end: usize,
2727    dim: usize,
2728    ranges: [Range<usize>; D],
2729    tensor: Tensor<B, D, K>,
2730}
2731
2732impl<B: Backend, const D: usize, K: BasicOps<B>> Iterator for DimIter<B, D, K> {
2733    type Item = Tensor<B, D, K>;
2734
2735    fn next(&mut self) -> Option<Self::Item> {
2736        if self.start >= self.end {
2737            return None;
2738        }
2739
2740        let mut ranges = self.ranges.clone();
2741        ranges[self.dim] = self.start..(self.start + 1);
2742
2743        let slice = self.tensor.clone().slice(ranges);
2744        self.start += 1;
2745
2746        Some(slice)
2747    }
2748}
2749
2750impl<B: Backend, const D: usize, K: BasicOps<B>> DoubleEndedIterator for DimIter<B, D, K> {
2751    fn next_back(&mut self) -> Option<Self::Item> {
2752        if self.start >= self.end {
2753            return None;
2754        }
2755
2756        let mut ranges = self.ranges.clone();
2757        ranges[self.dim] = (self.end - 1)..self.end;
2758
2759        let slice = self.tensor.clone().slice(ranges);
2760        self.end = self.end.saturating_sub(1);
2761
2762        Some(slice)
2763    }
2764}
2765
2766impl<B: Backend, const D: usize, K: BasicOps<B>> DimIter<B, D, K> {
2767    fn new(tensor: Tensor<B, D, K>, dim: usize) -> Self {
2768        let dims = tensor.dims();
2769        let ranges = dims
2770            .iter()
2771            .map(|&dim| 0..dim)
2772            .collect::<Vec<Range<usize>>>();
2773        let ranges: [Range<usize>; D] = ranges.try_into().unwrap();
2774        Self {
2775            end: dims[dim],
2776            ranges,
2777            start: 0,
2778            dim,
2779            tensor,
2780        }
2781    }
2782}
2783
2784impl<B, const D: usize, K> Tensor<B, D, K>
2785where
2786    B: Backend,
2787    K: BasicOps<B>,
2788    <K as BasicOps<B>>::Elem: Debug,
2789{
2790    #[inline]
2791    fn push_newline_indent(acc: &mut String, indent: usize) {
2792        acc.push('\n');
2793        for _ in 0..indent {
2794            acc.push(' ');
2795        }
2796    }
2797    fn fmt_inner_tensor(
2798        &self,
2799        acc: &mut String,
2800        depth: usize,
2801        multi_index: &mut [usize],
2802        range: (usize, usize),
2803        precision: Option<usize>,
2804    ) {
2805        let (start, end) = range;
2806        for i in start..end {
2807            if i > 0 {
2808                acc.push_str(", ");
2809            }
2810            multi_index[depth] = i;
2811            let range: [Range<usize>; D] =
2812                core::array::from_fn(|i| multi_index[i]..multi_index[i] + 1);
2813
2814            let data = burn_std::reader::try_read_sync(self.clone().slice(range).into_data_async());
2815
2816            if let Some(Ok(data)) = data {
2817                let elem = data.iter::<<K as BasicOps<B>>::Elem>().next().unwrap();
2818                match (precision, K::name()) {
2819                    (Some(p), "Float") => acc.push_str(&format!("{elem:.p$}")),
2820                    (_, "Bool") => acc.push_str(&format!("{}", elem.to_bool())),
2821                    _ => acc.push_str(&format!("{elem:?}")),
2822                }
2823            } else {
2824                acc.push_str("<Tensor data not available>");
2825            }
2826        }
2827    }
2828
2829    fn fmt_outer_tensor(
2830        &self,
2831        acc: &mut String,
2832        depth: usize,
2833        multi_index: &mut [usize],
2834        print_options: &PrintOptions,
2835        summarize: bool,
2836        range: (usize, usize),
2837    ) {
2838        let (start, end) = range;
2839        for i in start..end {
2840            if i > start {
2841                acc.push(',');
2842                Self::push_newline_indent(acc, depth + 1);
2843            }
2844            acc.push('[');
2845            multi_index[depth] = i;
2846            self.display_recursive(acc, depth + 1, multi_index, print_options, summarize);
2847            acc.push(']');
2848        }
2849    }
2850
2851    /// Recursively formats the tensor data for display and appends it to the provided accumulator string.
2852    ///
2853    /// This function is designed to work with tensors of any dimensionality.
2854    /// It traverses the tensor dimensions recursively, converting the elements
2855    /// to strings and appending them to the accumulator string with the
2856    /// appropriate formatting.
2857    ///
2858    /// # Arguments
2859    ///
2860    /// * `acc` - A mutable reference to a `String` used as an accumulator for the formatted output.
2861    /// * `depth` - The current depth of the tensor dimensions being processed.
2862    /// * `multi_index` - A mutable slice of `usize` representing the current indices in each dimension.
2863    fn display_recursive(
2864        &self,
2865        acc: &mut String,
2866        depth: usize,
2867        multi_index: &mut [usize],
2868        print_options: &PrintOptions,
2869        summarize: bool,
2870    ) {
2871        let edge_items = print_options.edge_items;
2872
2873        if depth == 0 {
2874            acc.push('[');
2875        }
2876
2877        if depth == self.dims().len() - 1 {
2878            // if we are at the innermost dimension, just push its elements into the accumulator
2879            if summarize && self.dims()[depth] > 2 * edge_items {
2880                // print the starting `edge_items` elements
2881                self.fmt_inner_tensor(
2882                    acc,
2883                    depth,
2884                    multi_index,
2885                    (0, edge_items),
2886                    print_options.precision,
2887                );
2888                acc.push_str(", ...");
2889                // print the last `edge_items` elements
2890                self.fmt_inner_tensor(
2891                    acc,
2892                    depth,
2893                    multi_index,
2894                    (self.dims()[depth] - edge_items, self.dims()[depth]),
2895                    print_options.precision,
2896                );
2897            } else {
2898                // print all the elements
2899                self.fmt_inner_tensor(
2900                    acc,
2901                    depth,
2902                    multi_index,
2903                    (0, self.dims()[depth]),
2904                    print_options.precision,
2905                );
2906            }
2907        } else {
2908            // otherwise, iterate through the current dimension and recursively display the inner tensors
2909            if summarize && self.dims()[depth] > 2 * edge_items {
2910                self.fmt_outer_tensor(
2911                    acc,
2912                    depth,
2913                    multi_index,
2914                    print_options,
2915                    summarize,
2916                    (0, edge_items),
2917                );
2918
2919                acc.push(',');
2920                Self::push_newline_indent(acc, depth + 1);
2921                acc.push_str("...");
2922                Self::push_newline_indent(acc, depth + 1);
2923
2924                self.fmt_outer_tensor(
2925                    acc,
2926                    depth,
2927                    multi_index,
2928                    print_options,
2929                    summarize,
2930                    (self.dims()[depth] - edge_items, self.dims()[depth]),
2931                );
2932            } else {
2933                self.fmt_outer_tensor(
2934                    acc,
2935                    depth,
2936                    multi_index,
2937                    print_options,
2938                    summarize,
2939                    (0, self.dims()[depth]),
2940                );
2941            }
2942        }
2943
2944        if depth == 0 {
2945            acc.push(']');
2946        }
2947    }
2948}
2949
2950#[derive(Clone, Debug)]
2951/// Options for Tensor pretty printing
2952pub struct PrintOptions {
2953    /// number of elements to start summarizing tensor
2954    pub threshold: usize,
2955
2956    /// number of starting elements and ending elements to display
2957    pub edge_items: usize,
2958
2959    /// Precision for floating point numbers
2960    pub precision: Option<usize>,
2961}
2962
2963static PRINT_OPTS: RwLock<PrintOptions> = RwLock::new(PrintOptions::const_default());
2964
2965impl PrintOptions {
2966    /// Print options with default values
2967    pub const fn const_default() -> Self {
2968        Self {
2969            threshold: 1000,
2970            edge_items: 3,
2971            precision: None,
2972        }
2973    }
2974}
2975
2976impl Default for PrintOptions {
2977    fn default() -> Self {
2978        Self::const_default()
2979    }
2980}
2981
2982/// Set print options
2983pub fn set_print_options(options: PrintOptions) {
2984    let mut print_opts = PRINT_OPTS.write().unwrap();
2985    *print_opts = options;
2986}
2987
2988/// Pretty print tensors
2989impl<B, const D: usize, K> core::fmt::Display for Tensor<B, D, K>
2990where
2991    B: Backend,
2992    B::IntElem: core::fmt::Display,
2993    K: BasicOps<B>,
2994    <K as BasicOps<B>>::Elem: Debug,
2995{
2996    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
2997        writeln!(f, "Tensor {{")?;
2998
2999        {
3000            // Do not lock the mutex for the whole function
3001            let mut po = { PRINT_OPTS.read().unwrap().clone() };
3002
3003            // Override the precision if it is set from the formatter
3004            // This will be possible when the tensor is printed using the `{:.*}` syntax
3005            if let Some(precision) = f.precision() {
3006                po.precision = Some(precision);
3007            }
3008
3009            let mut acc = String::new();
3010            let mut multi_index = vec![0; D];
3011            let summarize = self.shape().num_elements() > po.threshold;
3012
3013            self.display_recursive(&mut acc, 0, &mut multi_index, &po, summarize);
3014
3015            writeln!(f, "  data:")?;
3016            write!(f, "{acc}")?;
3017            writeln!(f, ",")?;
3018        }
3019
3020        writeln!(f, "  shape:  {:?},", self.dims())?;
3021        writeln!(f, "  device:  {:?},", self.device())?;
3022        writeln!(f, "  backend:  {:?},", B::name(&self.device()))?;
3023        writeln!(f, "  kind:  {:?},", K::name())?;
3024
3025        let dtype = self.primitive.dtype();
3026
3027        writeln!(f, "  dtype:  {:?},", dtype.name())?;
3028        write!(f, "}}")
3029    }
3030}
3031
3032/// Trait used for movedim arguments
3033pub trait MovedimArgs {
3034    /// Converts into a set of dimensions `Vec<usize>` for the `tensor.movedim()` function
3035    fn into_dim_vec<const D: usize>(self) -> Vec<usize>;
3036}
3037
3038impl MovedimArgs for Vec<i32> {
3039    fn into_dim_vec<const D: usize>(self) -> Vec<usize> {
3040        let set = self
3041            .iter()
3042            .map(|&dim| {
3043                if dim < 0 {
3044                    (D as i32 + dim) as usize
3045                } else {
3046                    dim as usize
3047                }
3048            })
3049            .collect::<Vec<usize>>();
3050        check!(TensorCheck::movedim_args_vec::<D>(&set));
3051
3052        set
3053    }
3054}
3055
3056impl MovedimArgs for Vec<usize> {
3057    fn into_dim_vec<const D: usize>(self) -> Vec<usize> {
3058        check!(TensorCheck::movedim_args_vec::<D>(&self));
3059        self
3060    }
3061}
3062
3063impl MovedimArgs for usize {
3064    #[allow(clippy::vec_init_then_push)]
3065    fn into_dim_vec<const D: usize>(self) -> Vec<usize> {
3066        check!(TensorCheck::movedim_args_usize::<D>(self));
3067
3068        let mut set = Vec::with_capacity(1);
3069        set.push(self);
3070
3071        set
3072    }
3073}
3074
3075impl MovedimArgs for i32 {
3076    #[allow(clippy::vec_init_then_push)]
3077    fn into_dim_vec<const D: usize>(self) -> Vec<usize> {
3078        check!(TensorCheck::movedim_args_i32::<D>(self));
3079
3080        let dim = if self < 0 {
3081            (D as i32 + self) as usize
3082        } else {
3083            self as usize
3084        };
3085
3086        let mut set = Vec::with_capacity(1);
3087        set.push(dim);
3088
3089        set
3090    }
3091}
3092
3093/// Trait used for reshape arguments.
3094pub trait ReshapeArgs<const D2: usize>: Debug {
3095    /// Converts to a shape.
3096    fn into_shape<const D: usize>(self, source: Shape) -> Shape;
3097}
3098
3099impl<const D2: usize, I: AsIndex> ReshapeArgs<D2> for [I; D2] {
3100    fn into_shape<const D: usize>(self, source: Shape) -> Shape {
3101        unwrap_shape_reshape(source.reshape(self))
3102    }
3103}
3104
3105impl<const D2: usize> ReshapeArgs<D2> for Shape {
3106    fn into_shape<const D: usize>(self, source: Shape) -> Shape {
3107        unwrap_shape_reshape(source.reshape(self))
3108    }
3109}
3110
3111/// Trait used for broadcast arguments.
3112pub trait BroadcastArgs<const D1: usize, const D2: usize> {
3113    /// Converts to a shape.
3114    fn into_shape(self, shape: &Shape) -> Shape;
3115}
3116
3117impl<const D1: usize, const D2: usize> BroadcastArgs<D1, D2> for Shape {
3118    fn into_shape(self, _shape: &Shape) -> Shape {
3119        self
3120    }
3121}
3122
3123impl<const D1: usize, const D2: usize, E: AsIndex> BroadcastArgs<D1, D2> for [E; D2] {
3124    // Passing -1 as the size for a dimension means not changing the size of that dimension.
3125    fn into_shape(self, shape: &Shape) -> Shape {
3126        if self.len() < shape.num_dims() {
3127            panic!("Broadcast arguments must be greater than the number of dimensions");
3128        }
3129
3130        // Zip the two shapes in reverse order and replace -1 with the actual dimension value.
3131        let new_shape: Vec<_> = self
3132            .iter()
3133            .rev()
3134            .map(|x| {
3135                let primitive = x.as_index();
3136                if primitive < -1 || primitive == 0 {
3137                    panic!("Broadcast arguments must be positive or -1");
3138                }
3139                primitive
3140            })
3141            .zip(shape.iter().rev().chain(repeat(&0)).take(self.len())) // Pad the original shape with 0s
3142            .map(|(x, &y)| if x == -1 { y } else { x as usize })
3143            .collect::<Vec<_>>()
3144            .into_iter()
3145            .rev()
3146            .collect();
3147
3148        if new_shape.contains(&0) {
3149            panic!("Cannot substitute -1 for a non-existing dimension");
3150        }
3151
3152        let new_shape: [usize; D2] = new_shape.try_into().unwrap();
3153
3154        Shape::from(new_shape)
3155    }
3156}
3157
3158impl<B, const D: usize, K> Serialize for Tensor<B, D, K>
3159where
3160    B: Backend,
3161    K: BasicOps<B>,
3162    K::Elem: Debug + Copy + Serialize,
3163{
3164    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
3165        let data = self.to_data();
3166        data.serialize(serializer)
3167    }
3168}
3169
3170impl<'de, B, const D: usize, K> Deserialize<'de> for Tensor<B, D, K>
3171where
3172    B: Backend,
3173    K: BasicOps<B>,
3174    K::Elem: Debug + Copy + Deserialize<'de>,
3175{
3176    fn deserialize<De: Deserializer<'de>>(deserializer: De) -> Result<Self, De::Error> {
3177        let tensor = Tensor::from_data(
3178            TensorData::deserialize(deserializer)?,
3179            &<B::Device as Default>::default(),
3180        );
3181        Ok(tensor)
3182    }
3183}
3184
3185#[cfg(test)]
3186mod tests {
3187    use burn_std::SliceOps;
3188
3189    use crate::{Shape, s};
3190
3191    #[test]
3192    fn slice_range_single_dim_leading() {
3193        let shape = Shape::new([8, 4]);
3194
3195        // Half-open range
3196        let slices = shape.clone().into_slices([0..5]);
3197        assert_eq!(slices[0].to_range(8), 0..5);
3198        let slices = shape.clone().into_slices([-3..-1]);
3199        assert_eq!(slices[0].to_range(8), 5..7);
3200
3201        // Inclusive range
3202        let slices = shape.clone().into_slices([0..=4]);
3203        assert_eq!(slices[0].to_range(8), 0..5);
3204        let slices = shape.clone().into_slices([-2..=-1]);
3205        assert_eq!(slices[0].to_range(8), 6..8);
3206
3207        // Unbounded start
3208        let slices = shape.clone().into_slices([..3]);
3209        assert_eq!(slices[0].to_range(8), 0..3);
3210        let slices = shape.clone().into_slices([..-5]);
3211        assert_eq!(slices[0].to_range(8), 0..3);
3212
3213        // Unbounded end
3214        let slices = shape.clone().into_slices([5..]);
3215        assert_eq!(slices[0].to_range(8), 5..8);
3216        let slices = shape.clone().into_slices([-3..]);
3217        assert_eq!(slices[0].to_range(8), 5..8);
3218
3219        // Full range
3220        let slices = shape.into_slices([..]);
3221        assert_eq!(slices[0].to_range(8), 0..8);
3222    }
3223
3224    #[test]
3225    fn test_negative_slice_indices() {
3226        use crate::Slice;
3227
3228        // Test negative indices conversion
3229        let slice: Slice = (-3..-1).into();
3230        assert_eq!(slice.start, -3);
3231        assert_eq!(slice.end, Some(-1));
3232
3233        // Test to_range conversion with size 8
3234        let range = slice.to_range(8);
3235        assert_eq!(range, 5..7);
3236
3237        // Test with shape slice
3238        let shape = Shape::new([8, 4]);
3239        let result = shape.clone().into_slices([-3..-1]);
3240        assert_eq!(result[0].to_range(8), 5..7);
3241
3242        // Test more negative index cases
3243        let slice2: Slice = (-5..).into();
3244        assert_eq!(slice2.to_range(10), 5..10);
3245
3246        let slice3: Slice = (..-2).into();
3247        assert_eq!(slice3.to_range(10), 0..8);
3248
3249        // Test with s! macro - single dimension returns Slice directly
3250        let slice4 = s![-3..-1];
3251        assert_eq!(slice4.start, -3);
3252        assert_eq!(slice4.end, Some(-1));
3253    }
3254
3255    #[test]
3256    fn slice_range_multi_dim() {
3257        let shape = Shape::new([8, 4]);
3258
3259        // Multiple ways to provide ranges
3260        let slices = shape.clone().into_slices([0..5, 0..4]);
3261        assert_eq!(slices[0].to_range(8), 0..5);
3262        assert_eq!(slices[1].to_range(4), 0..4);
3263
3264        let slices = shape.clone().into_slices([0.., 0..]);
3265        assert_eq!(slices[0].to_range(8), 0..8);
3266        assert_eq!(slices[1].to_range(4), 0..4);
3267
3268        let slices = shape.clone().into_slices([0..=7, 0..=3]);
3269        assert_eq!(slices[0].to_range(8), 0..8);
3270        assert_eq!(slices[1].to_range(4), 0..4);
3271
3272        let slices = shape.clone().into_slices([0..5, 0..3]);
3273        assert_eq!(slices[0].to_range(8), 0..5);
3274        assert_eq!(slices[1].to_range(4), 0..3);
3275
3276        let slices = shape.into_slices([0.., 0..]);
3277        assert_eq!(slices[0].to_range(8), 0..8);
3278        assert_eq!(slices[1].to_range(4), 0..4);
3279    }
3280
3281    #[test]
3282    fn slice_range_multi_dim_index() {
3283        let shape = Shape::new([8, 4]);
3284
3285        // Indices (single integer) should also convert to correct range
3286        let slices = shape.clone().into_slices([0, 2]);
3287        assert_eq!(slices[0].to_range(8), 0..1);
3288        assert_eq!(slices[1].to_range(4), 2..3);
3289
3290        let slices = shape.into_slices([-1, -1]);
3291        assert_eq!(slices[0].to_range(8), 7..8);
3292        assert_eq!(slices[1].to_range(4), 3..4);
3293    }
3294
3295    #[test]
3296    fn slice_range_multi_dim_heterogeneous() {
3297        // Slice macro `s![]` can be used to provide different range types
3298        let shape = Shape::new([8, 4, 2]);
3299        let slice = s![0..5, .., -1];
3300        let slices = shape.into_slices(slice);
3301        assert_eq!(slices[0].to_range(8), 0..5);
3302        assert_eq!(slices[1].to_range(4), 0..4);
3303        assert_eq!(slices[2].to_range(2), 1..2);
3304
3305        let shape = Shape::new([8, 4, 2, 3]);
3306        let slice = s![..=4, 0..=3, .., -2..];
3307        let slices = shape.into_slices(slice);
3308        assert_eq!(slices[0].to_range(8), 0..5);
3309        assert_eq!(slices[1].to_range(4), 0..4);
3310        assert_eq!(slices[2].to_range(2), 0..2);
3311        assert_eq!(slices[3].to_range(3), 1..3);
3312
3313        let shape = Shape::new([3, 4]);
3314        let slice = s![1..-1, ..];
3315        let slices = shape.into_slices(slice);
3316        assert_eq!(slices[0].to_range(3), 1..2);
3317        assert_eq!(slices[1].to_range(4), 0..4);
3318    }
3319}