# hamstergem/hamster

Efficient, Immutable, Thread-Safe Collection classes for Ruby

Repository: https://github.com/hamstergem/hamster
Canonical: https://ross.abutalabs.com/products/hamster
Language: Ruby
License: NOASSERTION
License Family: other
Last push: 2021-11-30T17:59:47+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 6160, "days_push": 1737, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1901, forks 92 (observed 2026-08-28T04:05:51.585055+00:00)

## What it is
Hamster is a Ruby library providing efficient, immutable, thread-safe persistent data structures including Hash, Vector, Set, SortedSet, List, and Deque. Modifications return new copies while structurally sharing data with the original, making collections safe to share across threads.

## Use cases
- immutable data structures in ruby
- thread-safe collections for concurrent ruby code
- persistent hash and vector for functional programming
- lazy lists in ruby
- share collections between threads without locks
- replace mutable arrays and hashes with immutable versions

## When to choose
- you need immutable or persistent data structures in Ruby
- you want thread-safe collections shared across threads
- you prefer functional programming style with structural sharing
- you need lazy sequences via Hamster lists

## When to avoid
- you only need standard mutable Ruby collections
- you need actively developed software with recent releases
- you mutate stored objects and rely on deep immutability

## Facets
- artifact type: library
- maturity: maintenance
- function: serialization, developer-tools
- domain: developer-tools
- platform: ruby
- tags: immutable-collections, persistent-data-structures, thread-safety, functional-programming, algorithms

## Member repositories
- hamstergem/hamster (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:51.585055+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:11:56.651338+00:00, confidence not recorded.
  - readme: https://github.com/hamstergem/hamster (fetched 2026-08-28T04:05:51.585055+00:00, sha 2a42a46b1d36)
- Data as of 2026-08-30T08:39:29.467469+00:00.