https://github.com/raviqqe/hamt

Immutable and Memory-Efficient Maps and Sets in Go
https://github.com/raviqqe/hamt

functional-programming go hamt immutable map set

Last synced: 5 months ago
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Immutable and Memory-Efficient Maps and Sets in Go

• Host: GitHub
• URL: https://github.com/raviqqe/hamt
• Owner: raviqqe
• License: unlicense
• Created: 2017-10-29T02:13:23.000Z (almost 8 years ago)
• Default Branch: v2
• Last Pushed: 2025-03-25T08:42:19.000Z (7 months ago)
• Last Synced: 2025-04-08T18:19:36.935Z (6 months ago)
• Topics: functional-programming, go, hamt, immutable, map, set
• Language: Go
• Homepage:
• Size: 133 KB
• Stars: 240
• Watchers: 8
• Forks: 13
• Open Issues: 3
• Metadata Files:
  • Readme: README.md

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README

          
# hamt

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[![License](https://img.shields.io/github/license/raviqqe/hamt.svg?style=flat-square)][unlicense]

> For the old `any`-based API, refer to [the `main` branch](https://github.com/raviqqe/hamt/tree/main).

Immutable and Memory Efficient Maps and Sets in Go.

This package `hamt` provides immutable collection types of maps (associative arrays)

and sets implemented as Hash-Array Mapped Tries (HAMTs).

All operations of the collections, such as insert and delete, are immutable and

create new ones keeping original ones unmodified.

[Hash-Array Mapped Trie (HAMT)](https://en.wikipedia.org/wiki/Hash_array_mapped_trie)

is a data structure popular as a map (a.k.a. associative array or dictionary)

or set.

Its immutable variant is adopted widely by functional programming languages

like Scala and Clojure to implement immutable and memory-efficient associative

arrays and sets.

## Installation

```

go get github.com/raviqqe/hamt/v2

```

## Documentation

[GoDoc](https://godoc.org/github.com/raviqqe/hamt/v2)

## Technical notes

The implementation canonicalizes tree structures of HAMTs by eliminating

intermediate nodes during delete operations as described

in [the CHAMP paper][champ].

## References

- [Ideal Hash Trees](https://infoscience.epfl.ch/record/64398/files/idealhashtrees.pdf)

- [Optimizing Hash-Array Mapped Tries for Fast and Lean Immutable JVM Collections][champ]

## License

[The Unlicense][unlicense]

[champ]: https://michael.steindorfer.name/publications/oopsla15.pdf

[unlicense]: https://unlicense.org/