https://github.com/mikolalysenko/foreach-combination

Visit all k-combinations of an array in lexicographic order
https://github.com/mikolalysenko/foreach-combination

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Visit all k-combinations of an array in lexicographic order

• Host: GitHub
• URL: https://github.com/mikolalysenko/foreach-combination
• Owner: mikolalysenko
• License: mit
• Created: 2014-05-14T18:10:27.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-05-14T18:14:19.000Z (over 10 years ago)
• Last Synced: 2024-10-20T14:26:33.313Z (2 months ago)
• Language: JavaScript
• Size: 121 KB
• Stars: 10
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
foreach-combination

===================

Enumerate all k length subsets in an array.

# Example

```javascript

var kcomb = require("foreach-combination")

var array = [1, 2, 3, "a", "b", "c"]

kcomb(array, 3, function(x,y,z) {

  console.log(x, y, z)

})

```

Output:

```javascript

1 2 3

1 2 'a'

1 2 'b'

1 2 'c'

1 3 'a'

1 3 'b'

1 3 'c'

1 'a' 'b'

1 'a' 'c'

1 'b' 'c'

2 3 'a'

2 3 'b'

2 3 'c'

2 'a' 'b'

2 'a' 'c'

2 'b' 'c'

3 'a' 'b'

3 'a' 'c'

3 'b' 'c'

'a' 'b' 'c'

```

# Install

```

npm install foreach-combination

```

If you want to use this in a browser, then you should use [browserify](http://browserify.org/).

# API

#### `require("foreach-combination")(array, k, visit(x1,x2,...,xk)`

Visits all `k` size combinations in array in lexicographic order.

* `array` is an array

* `k` is the size of the combination to visit

* `visit(x1,x2,...xk)` is a callback that gets called once for each size k-subset of the array.  If `visit` returns a non-undefined value then the iteration is immediately terminated, and the result of `visit` is returned.

**Returns** The result of the last call to `visit`, or `undefined` if no value was ever returned.

**Note** If you know `k` in advance, you can avoid an extra dispatch by calling `require("foreach-combination")[k]` directly for any `k<32`

# Credits

(c) 2014 Mikola Lysenko. MIT License