custom-permutation v1.0.7

Fixed bugs

25.09.2023 - unChoices did not reflect always, fixed now.

Custom Permutation Generator

1. require / import

const CustomPermutation = require('custom-permutation')

2. Constructor

CustomPermutation(elList:[els...], choices:{ index: [els...]] }, nonChoices:{ index: [els...]] })

3. Usage explanation

example:

CustomPermutation(['a', 'b', 'c'], {1: ['a', 'b']}, {0: ['a']})

Permutate 3 elements which are 'a', 'b' and 'c' with below rules

- choices rule:

{ 1: ['a', 'b'] }

At index=1 there can only be the element 'a' or 'b'

- nonChoices rule:

{ 0: ['a'] }

At index=0 there can NOT be the element 'a'

Note: given index are considered as 0 based: index=0, index=1, etc.

4. Result set explanation:

Let's see all permutations, and which ones are valid or not.

• ['a', 'b', 'c'] : violates nonChoices rule: _first element is 'a', but shouldn't be 'a'
• ['a', 'c', 'b'] : violates nonChoices rule: first element is 'a', but shouldn't be 'a'
• ['b', 'a', 'c'] : ok
• ['b', 'c', 'a'] : violates choices rule: second element is 'c' but 'a' or 'b' is desired
• ['c', 'a', 'b'] : ok
• ['c', 'b', 'a'] : ok

So there are just 3 results that should be generated with this parameters.

5. Complete example

1. Create permutation

let customPerm = new CustomPermutation(
    ['a', 'b', 'c'],
    { 1: ['a', 'b'] },
    { 0: ['a'] }
);

2. Get next value

2.1. Use with next

let next = customPerm.next();

while (next) {
    // Use next
    console.log(next)

    // Get next
    next = customPerm.next();
}

2.2. Or use with generator

let generator = customPerm.generator();
let next = generator.next();

while (!next.done) {
    // Use next.value
    console.log(next.value)

    // Generate next one
    next = generator.next();
}

3. Output

Console

['b', 'a', 'c']\
['c', 'a', 'b']\
['c', 'b', 'a']