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use crate::{
core::prelude::*,
errors::prelude::*,
extensions::prelude::*,
};
/// `ArrayTrait` - Array Indexing functions
pub trait ArrayIndexing<T: ArrayElement> where Self: Sized + Clone {
/// Return an index of element at the given coordinates
///
/// # Arguments
///
/// * `coords` - vector representing the coordinates of the element in array
///
/// # Examples
///
/// ```
/// use arr_rs::prelude::*;
///
/// let arr: Array<i32> = Array::new(vec![1,2,3,4,5,6,7,8], vec![2, 2, 2]).unwrap();
///
/// let idx_1 = arr.index_at(&[0, 0, 0]).unwrap();
/// assert_eq!(0, idx_1);
///
/// let idx_2 = arr.index_at(&[1, 0, 1]).unwrap();
/// assert_eq!(5, idx_2);
///
/// let idx_3 = arr.index_at(&[1, 1, 1]).unwrap();
/// assert_eq!(7, idx_3);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn index_at(&self, coords: &[usize]) -> Result<usize, ArrayError>;
/// Return coordinates at the given index of element
///
/// # Arguments
///
/// * `index` - index of element in flattened array
///
/// # Examples
///
/// ```
/// use arr_rs::prelude::*;
///
/// let arr: Array<i32> = Array::new(vec![1,2,3,4,5,6,7,8], vec![2, 2, 2]).unwrap();
///
/// let coord_1 = arr.index_to_coord(0).unwrap();
/// assert_eq!(vec![0, 0, 0], coord_1);
///
/// let coord_2 = arr.index_to_coord(5).unwrap();
/// assert_eq!(vec![1, 0, 1], coord_2);
///
/// let coord_3 = arr.index_to_coord(7).unwrap();
/// assert_eq!(vec![1, 1, 1], coord_3);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn index_to_coord(&self, idx: usize) -> Result<Vec<usize>, ArrayError>;
/// Return an index of element at the given coordinates
///
/// # Arguments
///
/// * `coords` - vector representing the coordinates of the element in array
///
/// # Examples
///
/// ```
/// use arr_rs::prelude::*;
///
/// let arr: Array<i32> = Array::new(vec![1,2,3,4,5,6,7,8], vec![2, 2, 2]).unwrap();
///
/// let at_1 = arr.at(&[0, 0, 0]).unwrap();
/// assert_eq!(1, at_1);
///
/// let at_2 = arr.at(&[1, 0, 1]).unwrap();
/// assert_eq!(6, at_2);
///
/// let at_3 = arr.at(&[1, 1, 1]).unwrap();
/// assert_eq!(8, at_3);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn at(&self, coords: &[usize]) -> Result<T, ArrayError>;
/// Return a subarray of provided range
///
/// # Arguments
///
/// * `range` - starting and ending indices of elements to include in the subarray
///
/// # Examples
///
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = Array::<i32>::flat(vec![1, 2, 3, 4, 5, 6, 7, 8]).unwrap();
/// let expected = Array::<i32>::flat(vec![1, 2, 3, 4]).unwrap();
/// assert_eq!(expected, arr.slice(0..4).unwrap());
///
/// let arr = Array::<i32>::new(vec![1, 2, 3, 4, 5, 6, 7, 8], vec![2, 4]).unwrap();
/// let expected = Array::<i32>::flat(vec![1, 2, 3, 4]).unwrap();
/// assert_eq!(expected, arr.slice(0..1).unwrap());
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn slice(&self, range: std::ops::Range<usize>) -> Result<Array<T>, ArrayError>;
/// Return a subarray consisting on values on given indices.
///
/// # Arguments
///
/// * `indices` - indices which should be included in resulting array
///
/// # Examples
///
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = Array::<i32>::flat(vec![1, 2, 3, 4, 5, 6, 7, 8]).unwrap();
///
/// let expected = Array::<i32>::flat(vec![3, 5, 7]).unwrap();
/// let slice_1 = arr.indices_at(&[2, 4, 6]).unwrap();
/// assert_eq!(format!("{expected}"), format!("{slice_1}"));
///
/// let expected = Array::<i32>::flat(vec![4, 5, 3, 8, 6, 7, 1, 2]).unwrap();
/// let slice_1 = arr.indices_at(&[3, 4, 2, 7, 5, 6, 0, 1]).unwrap();
/// assert_eq!(format!("{expected}"), format!("{slice_1}"));
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn indices_at(&self, indices: &[usize]) -> Result<Array<T>, ArrayError>;
}
impl <T: ArrayElement> ArrayIndexing<T> for Array<T> {
fn index_at(&self, coords: &[usize]) -> Result<usize, ArrayError> {
if self.shape.len() != coords.len() {
Err(ArrayError::ParameterError { param: "coords", message: "length must match array dimension", })
} else if coords.iter().enumerate().any(|(i, _)| coords[i] >= self.shape[i]) {
Err(ArrayError::ParameterError { param: "coords", message: "value must match array shape", })
} else {
let result = self.shape.iter().enumerate().rev().fold((0, 1), |(mut index, mut stride), (i, &dim)| {
index += coords[i] * stride;
stride *= dim;
(index, stride)
}).0;
Ok(result)
}
}
fn index_to_coord(&self, idx: usize) -> Result<Vec<usize>, ArrayError> {
if idx >= self.len()? {
Err(ArrayError::ParameterError { param: "idx", message: "index must be smaller than array length", })
} else {
let result = self.shape.iter().rev().fold((idx, Vec::new()), |(ri, mut coords), &dim| {
coords.push(ri % dim);
(ri / dim, coords)
}).1.into_iter().rev().collect();
Ok(result)
}
}
fn at(&self, coords: &[usize]) -> Result<T, ArrayError> {
match self.index_at(coords) {
Ok(idx) => Ok(self.elements[idx].clone()),
Err(e) => Err(e),
}
}
fn slice(&self, range: std::ops::Range<usize>) -> Result<Self, ArrayError> {
if !(range.start <= range.end && range.end <= self.elements.len()) {
return Err(ArrayError::OutOfBounds { value: "slice range" })
}
if self.shape.len() == 1 {
Self::flat(self.elements[range].into())
} else if range.len() >= self.shape[0] {
Ok(self.clone())
} else {
let new_shape =
if range.len() > 1 { vec![range.len()].into_iter().chain(self.shape[1..].iter().copied()).collect() }
else { self.shape[1..].to_vec() };
let items: usize = new_shape.iter().product();
let stride = items / new_shape[0];
let start_index = new_shape[0] * range.start;
let mut new_elements = Vec::with_capacity(items);
(start_index..start_index + items).step_by(stride).for_each(|idx| {
new_elements.extend_from_slice(&self.elements[idx..idx + stride]);
});
Self::new(new_elements, new_shape)
}
}
fn indices_at(&self, indices: &[usize]) -> Result<Self, ArrayError> {
if self.ndim()? == 1 {
for &i in indices {
if i >= self.len()? { return Err(ArrayError::OutOfBounds { value: "indices" }) }
}
indices.iter()
.map(|&i| self[i].clone())
.collect::<Vec<T>>()
.to_array()
} else {
let arrs = self.split_axis(0)?;
for &i in indices {
if i >= arrs.len() { return Err(ArrayError::OutOfBounds { value: "indices" }) }
}
let new_shape = self.get_shape()?.update_at(0, indices.len());
indices.iter()
.flat_map(|&i| arrs[i].clone())
.collect::<Vec<T>>()
.to_array()
.reshape(&new_shape)
}
}
}
impl <T: ArrayElement> ArrayIndexing<T> for Result<Array<T>, ArrayError> {
fn index_at(&self, coords: &[usize]) -> Result<usize, ArrayError> {
self.clone()?.index_at(coords)
}
fn index_to_coord(&self, idx: usize) -> Result<Vec<usize>, ArrayError> {
self.clone()?.index_to_coord(idx)
}
fn at(&self, coords: &[usize]) -> Result<T, ArrayError> {
self.clone()?.at(coords)
}
fn slice(&self, range: std::ops::Range<usize>) -> Self {
self.clone()?.slice(range)
}
fn indices_at(&self, indices: &[usize]) -> Self {
self.clone()?.indices_at(indices)
}
}