Entries is a list of keyvalue pairs, with unique keys.
Methods as separate packages:

@extraentries/find
: use rollup to bundle this es module. 
@extraentries/find.min
: use in browser (browserify, uglifyjs).
After Mount St. Helens erupted, researchers had a blank slate from which to explore the science of ecological recovery. Scientist Charley Crisafulli was drawn to logcovered Spirit Lake, where nutrient rich waters fueled an unusually fast resurgence in fish, plant life and amphibians. It’s a phenomenon that continues to fascinate scientists everywhere. Originally broadcast in 2008. (1)
Stability: Experimental.
const entries = require('extraentries');
// import * as entries from 'extraentries';
// import * as entries from 'https://unpkg.com/extraentries@2.2.10/index.mjs'; (deno)
var x = [['a', 1], ['b', 2], ['c', 3], ['d', 4], ['e', 5]];
[...entries.filter(x, v => v % 2 === 1)];
// [ [ 'a', 1 ], [ 'c', 3 ], [ 'e', 5 ] ]
var x = [['a', 1], ['b', 2], ['c', 3], ['d', 4]];
entries.some(x, v => v > 10);
// false
var x = [['a', 1], ['b', 2], ['c', 3], ['d', 4]];
entries.min(x);
// [ 'd', 4 ]
var x = [['a', 1], ['b', 2], ['c', 3]];
[...entries.subsets(x)].map(a => [...a]);
// [
// [],
// [ [ 'a', 1 ] ],
// [ [ 'b', 2 ] ],
// [ [ 'a', 1 ], [ 'b', 2 ] ],
// [ [ 'c', 3 ] ],
// [ [ 'a', 1 ], [ 'c', 3 ] ],
// [ [ 'b', 2 ], [ 'c', 3 ] ],
// [ [ 'a', 1 ], [ 'b', 2 ], [ 'c', 3 ] ]
// ]
reference
Method  Action 

is  Checks if value is entries. 
get  Gets value at key. 
set  Sets value at key. 
remove  Deletes an entry. 
swap  Exchanges two values. 
size  Gets size of entries. 
head  Gets first entry. 
take  Keeps first n entries only. 
shift  Removes first entry. 
fromLists  Creates entries from lists. 
concat  Appends entries from maps, preferring last. 
flat  Flattens nested entries to given depth. 
chunk  Breaks entries into chunks of given size. 
filterAt  Gets entries with given keys. 
map  Updates values based on map function. 
filter  Keeps entries which pass a test. 
reduce  Reduces values to a single value. 
range  Finds smallest and largest entries. 
count  Counts values which satisfy a test. 
partition  Segregates values by test result. 
cartesianProduct  Lists cartesian product of entries. 
some  Checks if any value satisfies a test. 
zip  Combines matching entries from all entries. 
union  Gives entries present in any entries. 
intersection  Gives entries present in both entries. 
difference  Gives entries not present in another. 
symmetricDifference  Gives entries not present in both entries. 
isDisjoint  Checks if entries have no common keys. 
key  Picks an arbitrary key. 
value  Picks an arbitrary value. 
entry  Picks an arbitrary entry. 
subset  Gives an arbitrary subset. 
isEmpty  Checks if entries is empty. 
isEqual  Checks if two maps are equal. 
compare  Compares two entries. 
find  Finds a value passing a test. 
search  Finds key of an entry passing a test. 
scanWhile  Finds key of first entry not passing a test. 