A collection of functions for operating upon Lists.

**Lists** is a pair of key list and value list, with unique keys. It is an an
alternative to Entries. Unless *entries* are implemented as structs by v8,
lists should be more space efficient. This package includes common functions
related to querying **about** lists, **generating** them, **comparing** one with
another, finding their **size**, **adding** and **removing** entries, obtaining
its **properties**, getting a **part** of it, getting a **subset** entries in
it, **finding** an entry in it, performing **functional** operations,
**manipulating** it in various ways, **combining** together lists or its
sub-entries, of performing **set operations** upon it. All functions except
`fromEntries()`

take lists as 1st parameter.

This package is available in *Node.js* and *Web* formats. To use it on the web,
simply use the `extra_lists`

global variable after loading with a `<script>`

tag from the jsDelivr CDN.

Stability: Experimental.

```
const xlists = require('extra-lists');
// import * as xlists from 'extra-lists';
// import * as xlists from 'https://unpkg.com/extra-lists/index.mjs'; (deno)
var x = [['a', 'b', 'c', 'd', 'e'], [1, 2, 3, 4, 5]];
xlists.filter(x, v => v % 2 === 1);
// → [ [ 'a', 'c', 'e' ], [ 1, 3, 5 ] ]
var x = [['a', 'b', 'c', 'd'], [1, 2, -3, -4]];
xlists.some(x, v => v > 10);
// → false
var x = [['a', 'b', 'c', 'd'], [1, 2, -3, -4]];
xlists.min(x);
// → -4
var x = [['a', 'b', 'c'], [1, 2, 3]];
[...xlists.subsets(x)].map(a => [[...a[0]], [...a[1]]]);
// → [
// → [ [], [] ],
// → [ [ 'a' ], [ 1 ] ],
// → [ [ 'b' ], [ 2 ] ],
// → [ [ 'a', 'b' ], [ 1, 2 ] ],
// → [ [ 'c' ], [ 3 ] ],
// → [ [ 'a', 'c' ], [ 1, 3 ] ],
// → [ [ 'b', 'c' ], [ 2, 3 ] ],
// → [ [ 'a', 'b', 'c' ], [ 1, 2, 3 ] ]
// → ]
```

## Index

Property | Description |
---|---|

is | Check if value is lists. |

keys | List all keys. |

values | List all values. |

entries | List all key-value pairs. |

fromEntries | Convert lists to entries. |

size | Find the size of lists. |

isEmpty | Check if lists is empty. |

compare | Compare two lists. |

isEqual | Check if two lists are equal. |

get | Get value at key. |

getAll | Gets values at keys. |

getPath | Get value at path in nested lists. |

hasPath | Check if nested lists has a path. |

set | Set value at key. |

swap | Exchange two values. |

remove | Remove value at key. |

head | Get first entry from lists (default order). |

tail | Get lists without its first entry (default order). |

take | Keep first n entries only (default order). |

drop | Remove first n entries (default order). |

count | Count values which satisfy a test. |

countAs | Count occurrences of values. |

min | Find smallest value. |

minEntry | Find smallest entry. |

max | Find largest value. |

maxEntry | Find largest entry. |

range | Find smallest and largest values. |

rangeEntries | Find smallest and largest entries. |

subsets | List all possible subsets. |

randomKey | Pick an arbitrary key. |

randomValue | Pick an arbitrary value. |

randomEntry | Pick an arbitrary entry. |

randomSubset | Pick an arbitrary subset. |

has | Check if lists has a key. |

hasValue | Check if lists has a value. |

hasEntry | Check if lists has an entry. |

hasSubset | Check if lists has a subset. |

find | Find first value passing a test (default order). |

findAll | Find values passing a test. |

search | Finds key of an entry passing a test. |

searchAll | Find keys of entries passing a test. |

searchValue | Find a key with given value. |

searchValueAll | Find keys with given value. |

forEach | Call a function for each value. |

some | Check if any value satisfies a test. |

every | Check if all values satisfy a test. |

map | Transform values of entries. |

reduce | Reduce values of entries to a single value. |

filter | Keep entries which pass a test. |

filterAt | Keep entries with given keys. |

reject | Discard entries which pass a test. |

rejectAt | Discard entries with given keys. |

flat | Flatten nested lists to given depth. |

flatMap | Flatten nested lists, based on map function. |

zip | Combine matching entries from all lists. |

partition | Segregate values by test result. |

partitionAs | Segregate entries by similarity. |

chunk | Break lists into chunks of given size. |

concat | Append entries from all lists, preferring last. |

join | Join lists together into a string. |

isDisjoint | Check if lists have no common keys. |

unionKeys | Obtain keys present in any lists. |

union | Obtain entries present in any lists. |

intersection | Obtain entries present in both lists. |

difference | Obtain entries not present in another lists. |

symmetricDifference | Obtain entries not present in both lists. |