validation: A data-type like Either but with an accumulating Applicative

[ bsd3, data, library ] [ Propose Tags ]

A data-type like Either but with differing properties and type-class instances.

Library support is provided for this different representation, include lens-related functions for converting between each and abstracting over their similarities.

The Validation data type is isomorphic to Either, but has an instance of Applicative that accumulates on the error side. That is to say, if two (or more) errors are encountered, they are appended using a Semigroup operation.

As a consequence of this Applicative instance, there is no corresponding Bind or Monad instance. Validation is an example of, "An applicative functor that is not a monad."

Versions 0.3.0, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.4.0, 0.4.1, 0.4.2, 0.4.3, 0.5.0, 0.5.1, 0.5.2, 0.5.3, 0.5.4, 0.5.5, 0.6.0, 0.6.1, 0.6.2, 0.6.3, 1
Change log changelog
Dependencies base (>=4.5 && <5), bifunctors (>=5.1 && <6), deepseq (>=1.2 && <1.5), ghc-prim (==0.2.0.0), lens (==4.*), semigroupoids (==5.*), semigroups (>=0.8 && <1) [details]
License BSD-3-Clause
Copyright Copyright (C) 2010-2013 Tony Morris, Nick Partridge Copyright (C) 2014,2015 NICTA Limited Copyright (c) 2016,2017, Commonwealth Scientific and Industrial Research Organisation (CSIRO) ABN 41 687 119 230.
Author Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ> <dibblego>, Nick Partridge <nkpart>
Maintainer Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ> <dibblego>, Nick Partridge <nkpart>, Queensland Functional Programming Lab <oᴉ˙ldɟb@llǝʞsɐɥ>
Revised Revision 1 made by qfpl at Wed Oct 10 03:23:35 UTC 2018
Category Data
Home page https://github.com/qfpl/validation
Bug tracker https://github.com/qfpl/validation/issues
Source repo head: git clone git@github.com:qfpl/validation.git
Uploaded by qfpl at Mon Feb 26 01:21:39 UTC 2018
Distributions LTSHaskell:1, NixOS:1, Stackage:1
Downloads 8280 total (89 in the last 30 days)
Rating 2.5 (votes: 3) [estimated by rule of succession]
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Status Docs available [build log]
Last success reported on 2018-02-26 [all 1 reports]
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