Struct grid::Grid

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pub struct Grid<T> { /* private fields */ }

Expand description

Stores elements of a certain type in a 2D grid structure.

Uses a rust Vec<T> type to reference the grid data on the heap. Also the number of rows and columns are stored in the grid data structure.

The size limit of a grid is rows * cols < usize.

The grid data is stored in a row-major memory layout.

Implementations§

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impl<T> Grid<T>

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pub fn new(rows: usize, cols: usize) -> Grid<T>
where T: Default,

Init a grid of size rows x columns with default values of the given type. For example this will generate a 2x3 grid of zeros:

use grid::Grid;
let grid : Grid<u8> = Grid::new(2,3);
assert_eq!(grid[0][0], 0);

If rows == 0 or cols == 0 the grid will be empty with no cols and rows.

pub fn init(rows: usize, cols: usize, data: T) -> Grid<T>
where T: Clone,

Init a grid of size rows x columns with the given data element.

If rows == 0 or cols == 0 the grid will be empty with no cols and rows.

pub fn from_vec(vec: Vec<T>, cols: usize) -> Grid<T>

Returns a grid from a vector with a given column length. The length of vec must be a multiple of cols.

For example:

use grid::Grid;
let grid = Grid::from_vec(vec![1,2,3,4,5,6], 3);
assert_eq!(grid.size(), (2, 3));

will create a grid with the following layout: [1,2,3] [4,5,6]

This example will fail, because vec.len() is not a multiple of cols:

use grid::Grid;
Grid::from_vec(vec![1,2,3,4,5], 3);

Panics

This panics if the vector length isn’t a multiple of the number of columns.

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pub unsafe fn get_unchecked(&self, row: usize, col: usize) -> &T

Returns a reference to an element, without performing bound checks. Generally not recommended, use with caution!

Safety

Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used.

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pub unsafe fn get_unchecked_mut(&mut self, row: usize, col: usize) -> &mut T

Returns a mutable reference to an element, without performing bound checks. Generally not recommended, use with caution!

Safety

Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used.

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pub fn get(&self, row: usize, col: usize) -> Option<&T>

Access a certain element in the grid. Returns None if an element beyond the grid bounds is tried to be accessed.

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pub fn get_mut(&mut self, row: usize, col: usize) -> Option<&mut T>

Mutable access to a certain element in the grid. Returns None if an element beyond the grid bounds is tried to be accessed.

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pub fn size(&self) -> (usize, usize)

Returns the size of the gird as a two element tuple. First element are the number of rows and the second the columns.

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pub fn rows(&self) -> usize

Returns the number of rows of the grid.

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pub fn cols(&self) -> usize

Returns the number of columns of the grid.

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pub fn is_empty(&self) -> bool

Returns true if the grid contains no elements. For example:

use grid::*;
let grid : Grid<u8> = grid![];
assert!(grid.is_empty());

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pub fn clear(&mut self)

Clears the grid.

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pub fn iter(&self) -> Iter<'_, T>

Returns an iterator over the whole grid, starting from the first row and column.

use grid::*;
let grid: Grid<u8> = grid![[1,2][3,4]];
let mut iter = grid.iter();
assert_eq!(iter.next(), Some(&1));
assert_eq!(iter.next(), Some(&2));
assert_eq!(iter.next(), Some(&3));
assert_eq!(iter.next(), Some(&4));
assert_eq!(iter.next(), None);

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pub fn iter_mut(&mut self) -> IterMut<'_, T>

Returns an mutable iterator over the whole grid that allows modifying each value.

use grid::*;
let mut grid: Grid<u8> = grid![[1,2][3,4]];
let mut iter = grid.iter_mut();
let next = iter.next();
assert_eq!(next, Some(&mut 1));
*next.unwrap() = 10;

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pub fn iter_col(&self, col: usize) -> StepBy<Iter<'_, T>>

Returns an iterator over a column.

Examples

use grid::*;
let grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let mut col_iter = grid.iter_col(1);
assert_eq!(col_iter.next(), Some(&2));
assert_eq!(col_iter.next(), Some(&4));
assert_eq!(col_iter.next(), None);

Panics

Panics if the col index is out of bounds.

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pub fn iter_col_mut(&mut self, col: usize) -> StepBy<IterMut<'_, T>>

Returns a mutable iterator over a column.

Examples

use grid::*;
let mut grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let mut col_iter = grid.iter_col_mut(1);
let next = col_iter.next();
assert_eq!(next, Some(&mut 2));
*next.unwrap() = 10;
assert_eq!(grid[0][1], 10);

Panics

Panics if the col index is out of bounds.

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pub fn iter_row(&self, row: usize) -> Iter<'_, T>

Returns an iterator over a row.

Examples

use grid::*;
let grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let mut col_iter = grid.iter_row(1);
assert_eq!(col_iter.next(), Some(&3));
assert_eq!(col_iter.next(), Some(&4));
assert_eq!(col_iter.next(), Some(&5));
assert_eq!(col_iter.next(), None);

Panics

Panics if the row index is out of bounds.

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pub fn iter_row_mut(&mut self, row: usize) -> IterMut<'_, T>

Returns a mutable iterator over a row.

Examples

use grid::*;
let mut grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let mut col_iter = grid.iter_row_mut(1);
let next = col_iter.next();
*next.unwrap() = 10;
assert_eq!(grid[1][0], 10);

Panics

Panics if the row index is out of bounds.

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pub fn push_row(&mut self, row: Vec<T>)

Add a new row to the grid.

Examples

use grid::*;
let mut grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let row = vec![6,7,8];
grid.push_row(row);
assert_eq!(grid.rows(), 3);
assert_eq!(grid[2][0], 6);
assert_eq!(grid[2][1], 7);
assert_eq!(grid[2][2], 8);

Can also be used to init an empty grid:

use grid::*;
let mut grid: Grid<u8> = grid![];
let row = vec![1,2,3];
grid.push_row(row);
assert_eq!(grid.size(), (1, 3));

Panics

Panics if:

the grid is not empty and row.len() != grid.cols()
row.len() == 0

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pub fn push_col(&mut self, col: Vec<T>)

Add a new column to the grid.

Important: Please note that Grid uses a Row-Major memory layout. Therefore, the push_col() operation will be significantly slower compared to a push_row() operation.

Examples

use grid::*;
let mut grid: Grid<u8> = grid![[1, 2, 3][3, 4, 5]];
let col = vec![4,6];
grid.push_col(col);
assert_eq!(grid.cols(), 4);
assert_eq!(grid[0][3], 4);
assert_eq!(grid[1][3], 6);

Can also be used to init an empty grid:

use grid::*;
let mut grid: Grid<u8> = grid![];
let col = vec![1,2,3];
grid.push_col(col);
assert_eq!(grid.size(), (3, 1));

Panics

Panics if:

the grid is not empty and col.len() != grid.rows()
col.len() == 0

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pub fn pop_row(&mut self) -> Option<Vec<T>>

Removes the last row from a grid and returns it, or None if it is empty.

pub fn remove_row(&mut self, row_index: usize) -> Option<Vec<T>>

Remove a Row at the index and return a vector of it.

pub fn pop_col(&mut self) -> Option<Vec<T>>

Removes the last column from a grid and returns it, or None if it is empty.

Note that this operation is much slower than the pop_row() because the memory layout of Grid is row-major and removing a column requires a lot of move operations.

pub fn remove_col(&mut self, col_index: usize) -> Option<Vec<T>>

Remove a column at the index and return a vector of it.

pub fn insert_row(&mut self, index: usize, row: Vec<T>)

Insert a new row at the index and shifts all rows after down.

Examples

use grid::*;
let mut grid = grid![[1,2,3][4,5,6]];
grid.insert_row(1, vec![7,8,9]);
assert_eq!(grid[0], [1,2,3]);
assert_eq!(grid[1], [7,8,9]);
assert_eq!(grid[2], [4,5,6]);
assert_eq!(grid.size(), (3,3))

Panics

Panics if:

the grid is not empty and row.len() != grid.cols().
the index is greater than the number of rows

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pub fn insert_col(&mut self, index: usize, col: Vec<T>)

Insert a new column at the index.

Important! Insertion of columns is a lot slower than the lines insertion. This is because of the memory layout of the grid data structure.

Examples

use grid::*;
let mut grid = grid![[1,2,3][4,5,6]];
grid.insert_col(1, vec![9,9]);
assert_eq!(grid[0], [1,9,2,3]);
assert_eq!(grid[1], [4,9,5,6]);
assert_eq!(grid.size(), (2,4))

Panics

Panics if:

the grid is not empty and col.len() != grid.rows().
the index is greater than the number of columns

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pub fn flatten(&self) -> &Vec<T>

Returns a reference to the internal data structure of the grid.

Grid uses a row major layout. All rows are placed right after each other in the vector data structure.

pub fn into_vec(self) -> Vec<T>

Converts self into a vector without clones or allocation.

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pub fn transpose(&self) -> Grid<T>
where T: Clone,

Transpose the grid so that columns become rows in new grid.

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pub fn fill(&mut self, value: T)
where T: Clone,

Fills the grid with elements by cloning value.

pub fn fill_with<F>(&mut self, f: F)
where F: FnMut() -> T,

Fills the grid with elements returned by calling a closure repeatedly.

This method uses a closure to create new values. If you’d rather Clone a given value, use fill. If you want to use the Default trait to generate values, you can pass Default::default as the argument.

Examples

use grid::*;
let mut grid = grid![[1,2,3][4,5,6]];
grid.fill_with(Default::default);
assert_eq!(grid[0], [0,0,0]);
assert_eq!(grid[1], [0,0,0]);

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pub fn iter_rows(&self) -> GridRowIter<'_, T> ⓘ

Iterate over the rows of the grid. Each time an iterator over a single row is returned.

An item in this iterator is equal to a call to Grid.iter_row(row_index) of the corresponding row.

Examples

use grid::*;
let mut grid = grid![[1,2,3][4,5,6]];
let sum_by_row: Vec<u8> = grid.iter_rows().map(|row| row.sum()).collect();
assert_eq!(sum_by_row, vec![1+2+3, 4+5+6])

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pub fn iter_cols(&self) -> GridColIter<'_, T> ⓘ

Iterate over the columns of the grid. Each time an iterator over a single column is returned.

An item in this iterator is equal to a call to Grid.iter_col(col_index) of the corresponding column.

Examples

use grid::*;
let mut grid = grid![[1,2,3][4,5,6]];
let sum_by_col: Vec<u8> = grid.iter_cols().map(|col| col.sum()).collect();
assert_eq!(sum_by_col, vec![1+4, 2+5, 3+6])