Futures and Promises - List of Implementations

List of Implementations

Languages supporting futures, promises, concurrent logic variables, dataflow variables, or I-vars include:

• ABCL/f
• Alice ML
• AmbientTalk (including first-class resolvers and read-only promises)
• Clojure
• C# 5 (through the await keyword)
• Dart
• Flow Java
• Glasgow Haskell (I-vars and M-vars only)
• Id (I-vars and M-vars only)
• Io
• Java through java.util.concurrent.Future
• Lucid (dataflow only)
• MultiLisp
• Oxygene
• Oz version 3
• Python 3.2, as proposed by the PEP 3148
• R (promises for lazy evaluation - still single threaded)
• Racket
• Scala
• Scheme
• μC++

Languages also supporting promise pipelining include:

• E
• Joule

Library-based implementations of futures:

• For Common Lisp: Eager Future2 and PCall
• For C++: C++11 (new revision of the C++ standard), the Boost library and the Dlib C++ Library
• For C#: The Parallel Extensions library
• For JavaScript:
  • Cujo.js's when.js provides promises conforming to the CommonJS Promises/A proposal.
  • jQuery's Deferred Object is based on the CommonJS Promises/A design.
  • The Dojo Toolkit supplies both promises and Twisted style Deferreds
• For Objective-C: MAFuture (reference)
• For OCaml: Lazy module implements lazy explicit futures.
• For Perl: Future and Reflex
• For Python: pythonfutures and Twisted's Deferreds
• For Ruby: The Promise gem
• For PHP: React/Promise