intset
v0.0.2
Published
A set implementation for integers
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IntSet.js
This library allows for an "efficient" storage mechanism for positive BigInt
values in
JavaScript. It allows for basic set-theoretic operations, like union and intersection as well.
Usage
You can create a new set pretty easily:
const IntSet = require('intset');
let set = new IntSet();
You can add elements to a set straightforward as well:
set.add(5n);
And remove them the same:
set.remove(5n);
Check for presence:
const is5inSet = set.contains(5n);
Or see if it's empty:
const isSetEmpty = set.isEmpty();
You can also do typical set operations on them as well:
const set6 = set1
.union(set2)
.intersection(set3)
.symmetricDifference(set4)
.difference(set5);
Implementation
Internally, the set is a series of BigInt's, where each one uses bit masking to determine the
presence or lack thereof of other numbers. This allows a set that represents n
numbers to
actually take up n / m
numbers of space, where m
represents the amount of storage used
per number. m
defaults to 64
bits, as this has (through experimentation) seemed to be
the fastest, but can be customized through an argument to new IntSet(customM)
.
This means that unions, intersections, and the like are implemented through bitwise operators on each masked number, rather than storing each number individually.
Contributing
Just make an issue, or file a pull request!