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• About
  • SparseSet8/16/32
• Status
• Related packages
• Installation
• Dependencies
• API
• Authors
• License

About

TypedArray-based sparse set implementations with extended ES Set API.

This package contains functionality which was previously part of and has been extracted from the @thi.ng/associative package.

SparseSet8/16/32

Sparse sets provide super fast (approx. 4x faster than the native Set impl) insertion & lookups for numeric values in the interval [0..n) . The implementation in this package provides most of the ES6 Set API and internally relies on 2 uint typed arrays, with the actual backing type dependent on n.

Furthermore, unless (or until) values are being removed from the set, they retain their original insertion order. For some use cases (e.g. deduplication of values), this property can be very useful.

import { defSparseSet } from "@thi.ng/sparse-set";

// create sparse set for value range 0 - 99 (uint8 backed)
const a = defSparseSet(100);
a.into([99, 42, 66, 23, 66, 42]);
// SparseSet8 { 99, 42, 66, 23 }

a.has(66)
// true

// sparse sets are iterable
[...a]
// [ 99, 42, 66, 23 ]

// attempting to add out-of-range values will fail
a.add(100)
// SparseSet8 { 99, 42, 66, 23 }

// create sparse set for 16 bit value range 0 - 0xffff (uint16 backed)
const b = defSparseSet(0x10000);
// SparseSet16 {}

Status

STABLE - used in production

Search or submit any issues for this package

Related packages

• @thi.ng/associative - ES Map/Set-compatible implementations with customizable equality semantics & supporting operations

Installation

yarn add @thi.ng/sparse-set

ESM import:

import * as ss from "@thi.ng/sparse-set";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/sparse-set"></script>

JSDelivr documentation

For Node.js REPL:

const ss = await import("@thi.ng/sparse-set");

Package sizes (brotli'd, pre-treeshake): ESM: 1.12 KB

Dependencies

• @thi.ng/api
• @thi.ng/associative
• @thi.ng/checks
• @thi.ng/errors

Note: @thi.ng/api is in most cases a type-only import (not used at runtime)

API

Generated API docs

TODO

Authors

• Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-sparse-set,
  title = "@thi.ng/sparse-set",
  author = "Karsten Schmidt",
  note = "https://thi.ng/sparse-set",
  year = 2019
}

License

© 2019 - 2025 Karsten Schmidt // Apache License 2.0