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</script></head><body><div id="package-header"><ul class="links" id="page-menu"><li><a href="src/Data-Neither.html">Source</a></li><li><a href="index.html">Contents</a></li><li><a href="doc-index.html">Index</a></li></ul><p class="caption">neither-0.1.0: Provide versions of Either with good monad and applicative instances.</p></div><div id="content"><div id="module-header"><p class="caption">Data.Neither</p></div><div id="table-of-contents"><p class="caption">Contents</p><ul><li><a href="#g:1">Applicative version
</a></li><li><a href="#g:2">Monadic version
</a></li><li><a href="#g:3">Monad transformer
</a></li><li><a href="#g:4">Neither typeclass
</a></li><li><a href="#g:5">Utility functions
</a></li></ul></div><div id="description"><p class="caption">Description</p><div class="doc"><p>This module provides three different datatypes: <code><a href="Data-Neither.html#t:AEither">AEither</a></code> is the
applicative version of Either. It does not provide a monad instance, and
<code><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html#v:mappend">mappend</a></code>s together error values. <code><a href="Data-Neither.html#t:MEither">MEither</a></code> is the monadic version, which
only holds onto the first error value. <code><a href="Data-Neither.html#t:MEitherT">MEitherT</a></code> is a monad transformer.
</p><p>Also, *Either datatypes and utility functions from Data.Either
are generalized with <code><a href="Data-Neither.html#t:Neither">Neither</a></code> type class.
</p></div></div><div id="synopsis"><p id="control.syn" class="caption expander" onclick="toggleSection('syn')">Synopsis</p><ul id="section.syn" class="hide" onclick="toggleSection('syn')"><li class="src short"><span class="keyword">data</span> <a href="#t:AEither">AEither</a> a b<ul class="subs"><li>= <a href="#v:ALeft">ALeft</a> a </li><li>| <a href="#v:ARight">ARight</a> b </li></ul></li><li class="src short"><a href="#v:aeither">aeither</a> :: (a -> c) -> (b -> c) -> <a href="Data-Neither.html#t:AEither">AEither</a> a b -> c</li><li class="src short"><span class="keyword">data</span> <a href="#t:MEither">MEither</a> a b<ul class="subs"><li>= <a href="#v:MLeft">MLeft</a> a </li><li>| <a href="#v:MRight">MRight</a> b </li></ul></li><li class="src short"><a href="#v:meither">meither</a> :: (a -> c) -> (b -> c) -> <a href="Data-Neither.html#t:MEither">MEither</a> a b -> c</li><li class="src short"><span class="keyword">newtype</span> <a href="#t:MEitherT">MEitherT</a> e m a = <a href="#v:MEitherT">MEitherT</a> {<ul class="subs"><li><a href="#v:runMEitherT">runMEitherT</a> :: m (<a href="Data-Neither.html#t:MEither">MEither</a> e a)</li></ul>}</li><li class="src short"><a href="#v:mapMEitherT">mapMEitherT</a> :: (m (<a href="Data-Neither.html#t:MEither">MEither</a> e a) -> n (<a href="Data-Neither.html#t:MEither">MEither</a> e' b)) -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m a -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e' n b</li><li class="src short"><a href="#v:throwMEither">throwMEither</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => e -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m a</li><li class="src short"><span class="keyword">class</span> <a href="#t:Neither">Neither</a> e <span class="keyword">where</span><ul class="subs"><li><a href="#v:left">left</a> :: a -> e a b</li><li><a href="#v:right">right</a> :: b -> e a b</li><li><a href="#v:either">either</a> :: (a -> c) -> (b -> c) -> e a b -> c</li></ul></li><li class="src short"><a href="#v:mapLeft">mapLeft</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (a -> c) -> e a b -> e c b</li><li class="src short"><a href="#v:mapRight">mapRight</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (b -> c) -> e a b -> e a c</li><li class="src short"><a href="#v:mapEither">mapEither</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (a -> c) -> (b -> d) -> e a b -> e c d</li><li class="src short"><a href="#v:lefts">lefts</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> m a</li><li class="src short"><a href="#v:rights">rights</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> m b</li><li class="src short"><a href="#v:partitionEithers">partitionEithers</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> (m a, m b)</li></ul></div><div id="interface"><h1 id="g:1">Applicative version
</h1><div class="top"><p class="src"><span class="keyword">data</span> <a name="t:AEither" class="def">AEither</a> a b <a href="src/Data-Neither.html#AEither" class="link">Source</a></p><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><a name="v:ALeft" class="def">ALeft</a> a</td><td class="doc empty"> </td></tr><tr><td class="src"><a name="v:ARight" class="def">ARight</a> b</td><td class="doc empty"> </td></tr></table></div><div class="subs instances"><p id="control.i:AEither" class="caption collapser" onclick="toggleSection('i:AEither')">Instances</p><div id="section.i:AEither" class="show"><table><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Typeable.html#t:Typeable2">Typeable2</a> <a href="Data-Neither.html#t:AEither">AEither</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="Data-Neither.html#t:Neither">Neither</a> <a href="Data-Neither.html#t:AEither">AEither</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Functor">Functor</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html#t:Monoid">Monoid</a> a => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Applicative.html#t:Applicative">Applicative</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> (<a href="Data-Neither.html#t:AEither">AEither</a> a b)</td><td class="doc empty"> </td></tr></table></div></div></div><div class="top"><p class="src"><a name="v:aeither" class="def">aeither</a> :: (a -> c) -> (b -> c) -> <a href="Data-Neither.html#t:AEither">AEither</a> a b -> c<a href="src/Data-Neither.html#aeither" class="link">Source</a></p></div><h1 id="g:2">Monadic version
</h1><div class="top"><p class="src"><span class="keyword">data</span> <a name="t:MEither" class="def">MEither</a> a b <a href="src/Data-Neither.html#MEither" class="link">Source</a></p><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><a name="v:MLeft" class="def">MLeft</a> a</td><td class="doc empty"> </td></tr><tr><td class="src"><a name="v:MRight" class="def">MRight</a> b</td><td class="doc empty"> </td></tr></table></div><div class="subs instances"><p id="control.i:MEither" class="caption collapser" onclick="toggleSection('i:MEither')">Instances</p><div id="section.i:MEither" class="show"><table><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Typeable.html#t:Typeable2">Typeable2</a> <a href="Data-Neither.html#t:MEither">MEither</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="Data-Neither.html#t:Neither">Neither</a> <a href="Data-Neither.html#t:MEither">MEither</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/failure-0.1.0.1/Control-Failure.html#t:Failure">Failure</a> e (<a href="Data-Neither.html#t:MEither">MEither</a> e)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Functor">Functor</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Applicative.html#t:Applicative">Applicative</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Eq.html#t:Eq">Eq</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Data.html#t:Data">Data</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Ord.html#t:Ord">Ord</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Read.html#t:Read">Read</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a b)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> a, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> b) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Text-Show.html#t:Show">Show</a> (<a href="Data-Neither.html#t:MEither">MEither</a> a b)</td><td class="doc empty"> </td></tr></table></div></div></div><div class="top"><p class="src"><a name="v:meither" class="def">meither</a> :: (a -> c) -> (b -> c) -> <a href="Data-Neither.html#t:MEither">MEither</a> a b -> c<a href="src/Data-Neither.html#meither" class="link">Source</a></p></div><h1 id="g:3">Monad transformer
</h1><div class="top"><p class="src"><span class="keyword">newtype</span> <a name="t:MEitherT" class="def">MEitherT</a> e m a <a href="src/Data-Neither.html#MEitherT" class="link">Source</a></p><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><a name="v:MEitherT" class="def">MEitherT</a></td><td class="doc empty"> </td></tr><tr><td colspan="2"><div class="subs fields"><p class="caption">Fields</p><dl><dt class="src"><a name="v:runMEitherT" class="def">runMEitherT</a> :: m (<a href="Data-Neither.html#t:MEither">MEither</a> e a)</dt><dd class="doc empty"> </dd></dl><div class="clear"></div></div></td></tr></table></div><div class="subs instances"><p id="control.i:MEitherT" class="caption collapser" onclick="toggleSection('i:MEitherT')">Instances</p><div id="section.i:MEitherT" class="show"><table><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="/usr/share/doc/ghc/html/libraries/failure-0.1.0.1/Control-Failure.html#t:Failure">Failure</a> e (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Control-Monad-Trans-Class.html#t:MonadTrans">MonadTrans</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Functor">Functor</a> m => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Functor">Functor</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Functor">Functor</a> m, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Applicative.html#t:Applicative">Applicative</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Control-Monad-IO-Class.html#t:MonadIO">MonadIO</a> m => <a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Control-Monad-IO-Class.html#t:MonadIO">MonadIO</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr><tr><td class="src"><a href="Control-Monad-Invert.html#t:MonadInvertIO">MonadInvertIO</a> m => <a href="Control-Monad-Invert.html#t:MonadInvertIO">MonadInvertIO</a> (<a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m)</td><td class="doc empty"> </td></tr></table></div></div></div><div class="top"><p class="src"><a name="v:mapMEitherT" class="def">mapMEitherT</a> :: (m (<a href="Data-Neither.html#t:MEither">MEither</a> e a) -> n (<a href="Data-Neither.html#t:MEither">MEither</a> e' b)) -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m a -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e' n b<a href="src/Data-Neither.html#mapMEitherT" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:throwMEither" class="def">throwMEither</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => e -> <a href="Data-Neither.html#t:MEitherT">MEitherT</a> e m a<a href="src/Data-Neither.html#throwMEither" class="link">Source</a></p></div><h1 id="g:4">Neither typeclass
</h1><div class="top"><p class="src"><span class="keyword">class</span> <a name="t:Neither" class="def">Neither</a> e <span class="keyword">where</span><a href="src/Data-Neither.html#Neither" class="link">Source</a></p><div class="subs methods"><p class="caption">Methods</p><p class="src"><a name="v:left" class="def">left</a> :: a -> e a b<a href="src/Data-Neither.html#left" class="link">Source</a></p><p class="src"><a name="v:right" class="def">right</a> :: b -> e a b<a href="src/Data-Neither.html#right" class="link">Source</a></p><p class="src"><a name="v:either" class="def">either</a> :: (a -> c) -> (b -> c) -> e a b -> c<a href="src/Data-Neither.html#either" class="link">Source</a></p></div><div class="subs instances"><p id="control.i:Neither" class="caption collapser" onclick="toggleSection('i:Neither')">Instances</p><div id="section.i:Neither" class="show"><table><tr><td class="src"><a href="Data-Neither.html#t:Neither">Neither</a> <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Either.html#t:Either">Either</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="Data-Neither.html#t:Neither">Neither</a> <a href="Data-Neither.html#t:AEither">AEither</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="Data-Neither.html#t:Neither">Neither</a> <a href="Data-Neither.html#t:MEither">MEither</a></td><td class="doc empty"> </td></tr></table></div></div></div><h1 id="g:5">Utility functions
</h1><div class="top"><p class="src"><a name="v:mapLeft" class="def">mapLeft</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (a -> c) -> e a b -> e c b<a href="src/Data-Neither.html#mapLeft" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:mapRight" class="def">mapRight</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (b -> c) -> e a b -> e a c<a href="src/Data-Neither.html#mapRight" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:mapEither" class="def">mapEither</a> :: <a href="Data-Neither.html#t:Neither">Neither</a> e => (a -> c) -> (b -> d) -> e a b -> e c d<a href="src/Data-Neither.html#mapEither" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:lefts" class="def">lefts</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> m a<a href="src/Data-Neither.html#lefts" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:rights" class="def">rights</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> m b<a href="src/Data-Neither.html#rights" class="link">Source</a></p></div><div class="top"><p class="src"><a name="v:partitionEithers" class="def">partitionEithers</a> :: (<a href="Data-Neither.html#t:Neither">Neither</a> e, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => m (e a b) -> (m a, m b)<a href="src/Data-Neither.html#partitionEithers" class="link">Source</a></p></div></div></div><div id="footer"><p>Produced by <a href="http://www.haskell.org/haddock/">Haddock</a> version 2.9.2</p></div></body></html>
