extra-map.web

A group of functions for working with Maps.
📦 Node.js, 🌐 Web, 📜 Files, 📰 Docs, 📘 Wiki.

A Map is a collection of key-value pairs, with unique keys. This package includes common set functions related to querying about map, 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 maps or its entries, of performing set operations upon it.

All functions except from*() take set as 1st parameter. Some names are borrowed from Haskell, Python, Java, Processing. Methods like swap() are pure and do not modify the map itself, while methods like swap$() do modify (update) the map 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 map = require('extra-map');
// import * as map from "extra-map";
// import * as map from "https://unpkg.com/extra-map/index.mjs"; (deno)

var x = new Map([["a", 1], ["b", 2], ["c", 3], ["d", 4]]);
map.swap(x, "a", "b");
// → Map(4) { "a" => 2, "b" => 1, "c" => 3, "d" => 4 }

var x = new Map([["a", 1],  ["b", 2],  ["c", 3], ["d", 4]]);
var y = new Map([["b", 20], ["c", 30], ["e", 50]]);
map.intersection(x, y);
// → Map(2) { "b" => 2, "c" => 3 }

var x = new Map([["a", 1], ["b", 2], ["c", 3], ["d", -2]]);
map.searchAll(x, v => Math.abs(v) === 2);
// → [ "b", "d" ]              ^                   ^

var x = new Map([["a", 1], ["b", 2], ["c", 3]]);
[...map.subsets(x)];
// → [
// →   Map(0) {},
// →   Map(1) { "a" => 1 },
// →   Map(1) { "b" => 2 },
// →   Map(2) { "a" => 1, "b" => 2 },
// →   Map(1) { "c" => 3 },
// →   Map(2) { "a" => 1, "c" => 3 },
// →   Map(2) { "b" => 2, "c" => 3 },
// →   Map(3) { "a" => 1, "b" => 2, "c" => 3 }
// → ]

Index

Property	Description
is	Check if value is a map.
keys	List all keys.
values	List all values.
entries	List all key-value pairs.
from	Convert entries to map.
from$	Convert entries to map.
fromLists	Convert lists to map.
fromKeys	Create a map from keys.
fromValues	Create a map from values.
compare	Compare two maps.
isEqual	Check if two maps are equal.
size	Find the size of a map.
isEmpty	Check if a map is empty.
get	Get value at key.
getAll	Get values at keys.
getPath	Get value at path in a nested map.
hasPath	Check if nested map has a path.
set	Set value at key.
set$	Set value at key.
setPath$	Set value at path in a nested map.
swap	Exchange two values.
swap$	Exchange two values.
remove	Remove value at key.
remove$	Remove value at key.
removePath$	Remove value at path in a nested map.
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.
head	Get first entry from map (default order).
tail	Get a map without its first entry (default order).
take	Keep first n entries only (default order).
take$	Keep first n entries only (default order).
drop	Remove first n entries (default order).
drop$	Remove first n entries (default order).
subsets	List all possible subsets.
randomKey	Pick an arbitrary key.
randomEntry	Pick an arbitrary entry.
randomSubset	Pick an arbitrary subset.
has	Check if map has a key.
hasValue	Check if map has a value.
hasEntry	Check if map has an entry.
hasSubset	Check if map has a subset.
find	Find first value passing a test (default order).
findAll	Find values passing a test.
search	Find 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 a map.
map$	Transform values of a map.
reduce	Reduce values of set to a single value.
filter	Keep entries which pass a test.
filter$	Keep entries which pass a test.
filterAt	Keep values at given keys.
filterAt$	Keep values at given keys.
reject	Discard entries which pass a test.
reject$	Discard entries which pass a test.
rejectAt	Discard values at given keys.
rejectAt$	Discard values at given keys.
flat	Flatten nested map to given depth.
flatMap	Flatten nested map, based on map function.
zip	Combine matching entries from maps.
partition	Segregate entries by test result.
partitionAs	Segregate entries by similarity.
chunk	Break map into chunks of given size.
concat	Append entries from maps, preferring last.
concat$	Append entries from maps, preferring last.
join	Join entries together into a string.
isDisjoint	Check if maps have no common keys.
unionKeys	Obtain keys present in any map.
union	Obtain entries present in any map.
union$	Obtain entries present in any map.
intersectionKeys	Obtain keys present in all maps.
intersection	Obtain entries present in both maps.
intersection$	Obtain entries present in both maps.
difference	Obtain entries not present in another map.
difference$	Obtain entries not present in another map.
symmetricDifference	Obtain entries not present in both maps.
symmetricDifference$	Obtain entries not present in both maps.
cartesianProduct	List cartesian product of maps.