Ross ROSS = Recommend OSS · open-source software intelligence for agents

vavr-io/vavr

vʌvr (formerly called Javaslang) is a non-commercial, non-profit object-functional library that runs with Java 8+. It aims to reduce the lines of code and increase code quality. observed · 2026-08-28

github.com/vavr-io/vavr · homepage · Java · Apache-2.0 (permissive) observed · 2026-08-28

Health v2 · maintenance only

81/100

  • Activity 99
  • Release rhythm 48
  • Longevity 100
How is this computed?

round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.

  • gap_med: 112
  • age_days: 4598
  • days_rel: 185
  • days_push: 8
  • n_releases_24m: 6

Full methodology

Adoption not part of the score

6166 stars · 672 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Vavr (formerly Javaslang) is an object-functional library for Java 8+ providing persistent immutable collections, pattern matching, and functional control structures like Option, Try, Either, and Lazy. It has no dependencies beyond the JVM and aims to reduce boilerplate while increasing code quality.

Use cases

  • use immutable persistent collections in Java
  • functional error handling with Try and Either in Java
  • pattern matching in Java
  • replace Java streams with functional collection operations
  • property-based testing in Java
  • avoid nulls with Option type in Java

When to choose

  • you want functional programming idioms in Java 8+ without adding dependencies
  • you need immutable, thread-safe data structures
  • you want expressive error handling and pattern matching in Java

When to avoid

  • your team is not familiar with functional programming concepts
  • you need minimal jar size or strict performance-critical collection code
  • you are locked into Java standard collections APIs across a large legacy codebase

Facets

library · maturity stable

serialization testing concurrency error-handling programming-languages developer-tools jvm functional-programming immutable-collections persistent-collections pattern-matching option-monad try-monad either tuple java-8 javaslang algorithms

3 sources

Member repositories

RepositoryRoleHealth v2
vavr-io/vavrmain81

For agents

markdown · JSON · MCP: product_card(name="vavr-io/vavr")

Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem