# bodil/im-rs

Assorted immutable collection datatypes for Rust

Repository: https://github.com/bodil/im-rs
Canonical: https://ross.abutalabs.com/products/im-rs
Homepage: http://immutable.rs/
Language: Rust
License: MPL-2.0
License Family: copyleft
Archived: true
Last push: 2024-08-19T20:59:41+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 3425, "days_push": 744, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1583, forks 117 (observed 2026-08-28T04:05:07.190781+00:00)

## What it is
im-rs is a Rust library providing fast immutable (persistent) collection datatypes such as vectors, hash maps, and hash sets with structural sharing. It ships in two variants: a thread-safe version (im) and a faster non-thread-safe version (im-rc).

## Use cases
- use immutable data structures in Rust for cheap cloning
- implement undo/redo with persistent collections
- share state safely across threads without locks
- build functional-style Rust applications with persistent maps and vectors
- efficiently snapshot large collections without copying

## When to choose
- you need cheap O(1) clones or snapshots of collections
- you want thread-safe immutable collections in Rust
- you're building editor-like or state-history-heavy applications

## When to avoid
- you only need standard mutable collections with no sharing requirements
- you need absolute maximum single-threaded mutation performance
- you're not working in Rust

## Facets
- artifact type: library
- maturity: stable
- function: serialization
- domain: developer-tools, programming-languages
- platform: rust
- tags: immutable-collections, persistent-data-structures, rust-crate, functional-data-structures, algorithms

## Member repositories
- bodil/im-rs (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:07.190781+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 2026-08-30T03:56:00.063402+00:00, confidence not recorded.
  - readme: https://github.com/bodil/im-rs (fetched 2026-08-28T04:05:07.190781+00:00, sha 324883b8da07)
- Data as of 2026-08-30T08:39:29.467469+00:00.