Trait Permutation

Source

pub trait Permutation<'a> {
    type Permutator: Iterator;

    // Required method
    fn permutation(&'a mut self) -> Self::Permutator;
}

Expand description

Create a permutation iterator that permute data in place. Built-in implementation return an object of HeapPermutation for slice/array and Vec. It return an object of HeapPermutationCellIter on data type of Rc<RefCell<&mut [T]>>.

§Example

For typical permutation:

use permutator::Permutation;
let mut data = vec![1, 2, 3];
data.permutation().for_each(|p| {
    // call multiple times. It'll print [1, 2, 3], [2, 1, 3], [3, 1, 2], 
    // [1, 3, 2], [2, 3, 1], and [3, 2, 1] respectively.
    println!("{:?}", p);
});

For k-permutation:

use permutator::{Combination, Permutation};
let data = [1, 2, 3, 4, 5];
let k = 3;

data.combination(k).for_each(|mut combination| {
    // print the first combination
    combination.permutation().for_each(|permuted| {
        // print permutation of each combination
        println!("{:?}", permuted);
    });
});
// All k-permutation printed

§See

HeapPermutation for more detail about how to use HeapPermutation.
HeapPermutationCellIter for more detail about how to use HeapPermutationCellIter
Example implementation on foreign type

§Breaking change from 0.3.x to 0.4

Since version 0.4.0, the first result return by this iterator will be the original value

Required Associated Types§

Source

type Permutator: Iterator

A permutation generator for a collection of data.

§See

Foreign implementation for an example different return type

Required Methods§

Source

fn permutation(&'a mut self) -> Self::Permutator

Create a permutation based on Heap’s algorithm. It return HeapPermutation object.

Implementations on Foreign Types§

Source §

impl<'a, T> Permutation<'a> for *mut [T]
where T: 'a + Clone,

Generate permutation a mutable pointer to slice of T It return HeapPermutation but it include an original value as first value return by Iterator.

§Warning

This implementation hid unsafe inside the permutation function but doesn’t provide any additional safety. User need to treat the return object as unsafe.

§Breaking change from 0.3.x to 0.4

Since version 0.4.0, the first result return by this iterator will be the original value

Source §

type Permutator = Chain<Once<()>, HeapPermutationRefIter<'a, T>>

Use HeapPermutation as permutation generator

Source §

fn permutation(&'a mut self) -> Chain<Once<()>, HeapPermutationRefIter<'_, T>>

Source §

impl<'a, T> Permutation<'a> for [T]
where T: 'a + Clone,

Generate permutation on an array or slice of T It return mostly similar to HeapPermutation but it include an original value as first value return by Iterator.

§Breaking change from 0.3.x to 0.4

Since version 0.4.0, the first result return by this iterator will be the original value

Source §

type Permutator = Chain<Once<Vec<T>>, HeapPermutationIterator<'a, T>>

Use HeapPermutation as permutation generator

Source §

fn permutation( &'a mut self, ) -> Chain<Once<Vec<T>>, HeapPermutationIterator<'_, T>>

Source §

impl<'a, T> Permutation<'a> for Rc<RefCell<&'a mut [T]>>
where T: 'a,

Generate a sharable permutation inside Rc<RefCell<&mut [T]>> It return HeapPermutationCellIter but it include an original value as first value return by Iterator.