Bluefin

Bluefin is an effect system for Haskell which allows you, through value-level handles, to freely mix a variety of effects including

• Bluefin.EarlyReturn, for early return
• Bluefin.Exception, for exceptions
• Bluefin.IO, for I/O
• Bluefin.State, for mutable state
• Bluefin.Stream, for streams

Introduction

For an introduction to Bluefin, see the docs in the Bluefin module.

Acknowledgements

Tom Ellis would like to thank many individuals for their work related to effect systems. Without the work of these individuals, Bluefin would not exist.

• Oleg Kiselyov, particularly for his work on effects and delimited continuations

• Michael Snoyman, particularly for his work on conduit and the ReaderT IO pattern

• Gabriella Gonzalez, particularly for her work on pipes

• Alexis King, particularly for her work on effect systems and delimited continuations

• David Feuer, particularly for [his observation about handlers and rank-2 types]( https://www.reddit.com/r/haskell/comments/pywuqg/comment/hexo2uu/

• Andrzej Rybczak for his work on effectful

• Francois Pottier for "Wandering through linear types, capabilities, and regions" http://pauillac.inria.fr/~fpottier/slides/fpottier-2007-05-linear-bestiary.pdf

• Jasper van de Jeugt, particularly for promoting the handle pattern https://jaspervdj.be/posts/2018-03-08-handle-pattern.html#fnref2