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Representable functors

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BSD3 licensed by Edward A. Kmett
Maintained by Edward A. Kmett


Build Status

This package provides representable functors for haskell. In category theory a representable functor (more pedantically a corepresentable functor) is one such that f a is isomorphic to x -> a. We choose the name Representable here because we are talking about haskell Functor instances, and they are all covariant, so this is the more natural notion of representability for Haskell.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on

-Edward Kmett


  • Updated array dependency
  • Added proper upper bounds on dependencies

  • Fixed issue #1. Did RULES parsing change with GHC 7.6.3?


  • Added Day Convolution


  • Required Distributive as a superclass
  • Renamed Data.Functor.Corepresentable to Data.Functor.Contravariant.Representable to finally clean up this long-standing abuse of terminology.


  • Removed intra-package dependencies
  • Added README.markdown
  • Added IRC build-bot notification
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