A pack of functions for working with Sets.
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A Set is a collection of unique values. This package includes common set functions related to querying about sets, generating them, comparing one with another, finding their size, adding and removing elements, obtaining its properties, getting a part of it, getting a subset elements in it, finding an element in it, performing functional operations, manipulating it in various ways, combining together sets or its elements, of performing set operations upon it.

All functions except from*() take set as 1st parameter. Methods like concat() are pure and do not modify the set itself, while methods like concat$() do modify (update) the set itself.

This package is available in Node.js and Web formats. The web format is exposed as extra_set standalone variable and can be loaded from jsDelivr CDN.

Stability: Experimental.

const set = require('extra-set');
// import * as set from "extra-set";
// import * as set from "https://unpkg.com/extra-set/index.mjs"; (Deno)

var x = new Set([1, 2, 3, 4, 5]);
var y = new Set([2, 4]);
set.difference(x, y);
// → Set(3) { 1, 3, 5 }

var x = new Set([1, 2, 3]);
var y = new Set([3, 4]);
set.isDisjoint(x, y);
// → false

var x = new Set([1, 2, 3, 4]);
var y = new Set([3, 4, 5, 6]);
set.symmetricDifference(x, y);
// → Set(4) { 1, 2, 5, 6 }

var x = new Set([1, 2, 3]);
[...set.subsets(x)];
// → [
// →   Set(0) {},
// →   Set(1) { 1 },
// →   Set(1) { 2 },
// →   Set(2) { 1, 2 },
// →   Set(1) { 3 },
// →   Set(2) { 1, 3 },
// →   Set(2) { 2, 3 },
// →   Set(3) { 1, 2, 3 }
// → ]
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Index

Property	Description
is	Check if value is a set.
values	List all values.
entries	List all value-value pairs.
from	Convert an iterable to set.
from$	Convert an iterable to set.
compare	Compare two sets.
isEqual	Check if two sets are equal.
size	Find the size of a set.
isEmpty	Check if a set is empty.
add	Add a value to set.
add$	Add a value to set.
remove	Delete a value from set.
remove$	Delete a value from set.
count	Count values which satisfy a test.
countAs	Count occurrences of values.
min	Find smallest value.
max	Find largest value.
range	Find smallest and largest entries.
head	Get first value from set (default order).
tail	Get a set without its first value (default order).
take	Keep first n values only (default order).
take$	Keep first n values only (default order).
drop	Remove first n values (default order).
drop$	Remove first n values (default order).
subsets	List all possible subsets.
randomValue	Pick an arbitrary value.
randomEntry	Pick an arbitrary entry.
randomSubset	Pick an arbitrary subset.
hasSubset	Checks if set has a subset.
has	Check if set has a value.
find	Find first value passing a test (default order).
findAll	Find all values passing a test.
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 a set.
map$	Transform values of a set.
reduce	Reduce values of set to a single value.
filter	Keep values which pass a test.
filter$	Keep values which pass a test.
reject	Discard values which pass a test.
reject$	Discard values which pass a test.
flat	Flatten nested set to given depth.
flatMap	Flatten nested set, based on map function.
partition	Segregate values by test result.
partitionAs	Segregates values by similarity.
chunk	Break set into chunks of given size.
concat	Append values from sets.
concat$	Append values from sets.
join	Join values together into a string.
isDisjoint	Check if sets have no value in common.
union	Obtain values present in any set.
union$	Obtain values present in any set.
intersection	Obtain values present in both sets.
intersection$	Obtain values present in both sets.
difference	Obtain values not present in another set.
difference$	Obtain values not present in another set.
symmetricDifference	Obtain values not present in both sets.
symmetricDifference$	Obtain values not present in both sets.
cartesianProduct	List cartesian product of sets.