The distributive package

[Tags: bsd3, library]

Haskell 98 Distributive functors -- Dual to Traversable


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Versions0.1, 0.1.1, 0.1.2, 0.2.0, 0.2.0.1, 0.2.1, 0.2.2, 0.3, 0.3.1, 0.3.2, 0.4, 0.4.1, 0.4.2, 0.4.3, 0.4.3.1, 0.4.3.2, 0.4.4
Change logCHANGELOG.markdown
Dependenciesbase (==4.*), tagged (>=0.7 && <1), transformers (>=0.2 && <0.4), transformers-compat (==0.1.*) [details]
LicenseBSD3
CopyrightCopyright (C) 2011-2013 Edward A. Kmett
AuthorEdward A. Kmett
MaintainerEdward A. Kmett <ekmett@gmail.com>
Stabilityprovisional
CategoryData Structures
Home pagehttp://github.com/ekmett/distributive/
Bug trackerhttp://github.com/ekmett/distributive/issues
Source repositoryhead: git clone git://github.com/ekmett/distributive.git
UploadedWed Jan 15 16:28:24 UTC 2014 by EdwardKmett
DistributionsDebian:0.4.4, Fedora:0.4.4, FreeBSD:0.4.4, LTSHaskell:0.4.4, NixOS:0.4.4, Stackage:0.4.4
Downloads120672 total (605 in last 30 days)
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StatusDocs available [build log]
Successful builds reported [all 1 reports]

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Readme for distributive-0.4

distributive

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This package provides the notion that is categorically dual to Traversable.

A Distributive Functor is one that you can push any functor inside of.

distribute :: (Functor f, Distributive g) => f (g a) -> g (f a)

Compare this with the corresponding Traversable notion, sequenceA.

sequenceA :: (Applicative f, Traversable g) => g (f a) -> f (g a)

This package includes instances for common types, and includes other methods similar to traverse which fuse the use of fmap.

We only require Functor rather than some dual notion to Applicative, because the latter cannot meaningfully exist in Haskell since all comonoids there are trivial.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett