Watch video


Latest snapshot Publish artifacts Publish documentation Kotlin version badge License

Functional companion to Kotlin’s Compiler & IDE

Λrrow Meta is a meta-programming library designed to build compiler plugins for Kotlin.

The Hello World tutorial describes a very simple plugin built with Λrrow Meta.

Built with Meta

The Λrrow org bundles independent plugins built with Λrrow meta.


Λrrow Analysis extends the capabilities of the Kotlin compiler with compile-time checked pre and post-conditions for functions, and invariants for types and mutable variables. This allows Λrrow Analysis to detect many common types of mistakes (like out-of-bounds indexing), which you can extend with additional checks for your particular domain.

Get started with Λrrow Analysis


Λrrow Optics provide a nice DSL to query and transform immutable values. Using Meta we provide automatic generation of the necessary boilerplate.

Get started with Λrrow Optics


Λrrow Proofs provides a way to declare contextual values, which are resolved at compile-time by the plug-in. Dependency Injection without the hassle!

Get started with Λrrow Proofs

Do you like Arrow?

Arrow Org