Claire (programming language)

Claire is a high-level functional and object-oriented programming language with rule processing abilities. It was designed by Yves Caseau at Bouygues' e-Lab research laboratory, and received its final definition in 2004.

Claire provides:

• A simple object system with parametric classes and methods
• Polymorphic and parametric functional programming
• Production rules triggered by events
• Versioned snapshots of the state of the whole system, or any part, supporting rollback and easy exploration of search spaces
• Explicit relations between entities; for example, two entities might be declared inverses of one another
• First-class sets with convenient syntax for set-based programming
• An expressive set-based type system allowing both second-order static and dynamic typing

Claire's reference implementation, consisting of an interpreter and compiler, was fully open-sourced with the release of version 3.3.46 in February 2009. Another implementation, WebClaire, is commercially supported.

Claire has, since 2022, a new reference version, CLAIRE4, which is written on top of the Go programming language. It has a new website with documentations and examples, together with a Github open source repository.