This is a Kotlin Multiplatform line-by-line transliteration port of jeromefroe/lru-rs.

Original Project: This port is based on jeromefroe/lru-rs. All design credit and project intent belong to the upstream authors; this repository is a faithful port to Kotlin Multiplatform with no behavioural changes intended.

This is an in-progress port. The goal is feature parity with the upstream Rust crate while providing a native Kotlin Multiplatform API. Every Kotlin file carries a // port-lint: source <path> header naming its upstream Rust counterpart so the AST-distance tool can track provenance.

The text below is reproduced and lightly edited from https://github.com/jeromefroe/lru-rs.git. It is the upstream project's own description and remains under the upstream authors' authorship; links have been rewritten to absolute upstream URLs so they continue to resolve from this repository.

Documentation

An implementation of a LRU cache. The cache supports put, get, get_mut and pop operations, all of which are O(1). This crate was heavily influenced by the LRU Cache implementation in an earlier version of Rust's std::collections crate.

The MSRV for this crate is 1.85.0.

Below is a simple example of how to instantiate and use a LRU cache.

extern crate lru;

use lru::LruCache;
use std::num::NonZeroUsize;

fn main() {
    let mut cache = LruCache::new(NonZeroUsize::new(2).unwrap());
    cache.put("apple", 3);
    cache.put("banana", 2);

    assert_eq!(*cache.get(&"apple").unwrap(), 3);
    assert_eq!(*cache.get(&"banana").unwrap(), 2);
    assert!(cache.get(&"pear").is_none());

    assert_eq!(cache.put("banana", 4), Some(2));
    assert_eq!(cache.put("pear", 5), None);

    assert_eq!(*cache.get(&"pear").unwrap(), 5);
    assert_eq!(*cache.get(&"banana").unwrap(), 4);
    assert!(cache.get(&"apple").is_none());

    {
        let v = cache.get_mut(&"banana").unwrap();
        *v = 6;
    }

    assert_eq!(*cache.get(&"banana").unwrap(), 6);
}

dependencies {
    implementation("io.github.kotlinmania:lru-kotlin:0.1.1")
}

./gradlew build
./gradlew test

• macOS arm64
• Linux x64
• Windows mingw-x64
• iOS arm64 / simulator-arm64 (Swift export + XCFramework)
• JS (browser + Node.js)
• Wasm-JS (browser + Node.js)
• Android (API 24+)

See AGENTS.md and CLAUDE.md for translator discipline, port-lint header convention, and Rust → Kotlin idiom mapping.

This Kotlin port is distributed under the same MIT license as the upstream jeromefroe/lru-rs. See LICENSE (and any sibling LICENSE-* / NOTICE files mirrored from upstream) for the full text.

Original work copyrighted by the lru-rs authors.
Kotlin port: Copyright (c) 2026 Sydney Renee and The Solace Project.

Thanks to the jeromefroe/lru-rs maintainers and contributors for the original Rust implementation. This port reproduces their work in Kotlin Multiplatform; bug reports about upstream design or behavior should go to the upstream repository.