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</script></head><body><div id="package-header"><ul class="links" id="page-menu"><li><a href="src/Control-Monad-RWS-Strict.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">mtl-2.0.1.0: Monad classes, using functional dependencies</p></div><div id="content"><div id="module-header"><table class="info"><tr><th>Portability</th><td>non-portable (multi-param classes, functional dependencies)</td></tr><tr><th>Stability</th><td>experimental</td></tr><tr><th>Maintainer</th><td>libraries@haskell.org</td></tr></table><p class="caption">Control.Monad.RWS.Strict</p></div><div id="table-of-contents"><p class="caption">Contents</p><ul><li><a href="#g:1">The RWS monad
</a></li><li><a href="#g:2">The RWST monad transformer
</a></li><li><a href="#g:3">Strict Reader-writer-state monads
</a></li></ul></div><div id="description"><p class="caption">Description</p><div class="doc"><p>Strict RWS monad.
</p><p>Inspired by the paper
<em>Functional Programming with Overloading and Higher-Order Polymorphism</em>,
Mark P Jones (<a href="http://web.cecs.pdx.edu/~mpj/">http://web.cecs.pdx.edu/~mpj/</a>)
Advanced School of Functional Programming, 1995.
</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">type</span> <a href="#t:RWS">RWS</a> r w s = <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s <a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Data-Functor-Identity.html#t:Identity">Identity</a></li><li class="src short"><a href="#v:rws">rws</a> :: (r -> s -> (a, s, w)) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a</li><li class="src short"><a href="#v:runRWS">runRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (a, s, w)</li><li class="src short"><a href="#v:evalRWS">evalRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (a, w)</li><li class="src short"><a href="#v:execRWS">execRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (s, w)</li><li class="src short"><a href="#v:mapRWS">mapRWS</a> :: ((a, s, w) -> (b, s, w')) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w' s b</li><li class="src short"><a href="#v:withRWS">withRWS</a> :: (r' -> s -> (r, s)) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r' w s a</li><li class="src short"><span class="keyword">newtype</span> <a href="#t:RWST">RWST</a> r w s m a = <a href="#v:RWST">RWST</a> {<ul class="subs"><li><a href="#v:runRWST">runRWST</a> :: r -> s -> m (a, s, w)</li></ul>}</li><li class="src short"><a href="#v:evalRWST">evalRWST</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> r -> s -> m (a, w)</li><li class="src short"><a href="#v:execRWST">execRWST</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> r -> s -> m (s, w)</li><li class="src short"><a href="#v:mapRWST">mapRWST</a> :: (m (a, s, w) -> n (b, s, w')) -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w' s n b</li><li class="src short"><a href="#v:withRWST">withRWST</a> :: (r' -> s -> (r, s)) -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r' w s m a</li><li class="src short">module <a href="Control-Monad-RWS-Class.html">Control.Monad.RWS.Class</a></li><li class="src short">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html">Control.Monad</a></li><li class="src short">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad-Fix.html">Control.Monad.Fix</a></li><li class="src short">module <a href="Control-Monad-Trans.html">Control.Monad.Trans</a></li><li class="src short">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html">Data.Monoid</a></li></ul></div><div id="interface"><h1 id="g:1">The RWS monad
</h1><div class="top"><p class="src"><span class="keyword">type</span> <a name="t:RWS" class="def">RWS</a> r w s = <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s <a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Data-Functor-Identity.html#t:Identity">Identity</a></p><div class="doc"><p>A monad containing an environment of type <code>r</code>, output of type <code>w</code>
and an updatable state of type <code>s</code>.
</p></div></div><div class="top"><p class="src"><a name="v:rws" class="def">rws</a> :: (r -> s -> (a, s, w)) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a</p><div class="doc"><p>Construct an RWS computation from a function.
(The inverse of <code><a href="Control-Monad-RWS-Strict.html#v:runRWS">runRWS</a></code>.)
</p></div></div><div class="top"><p class="src"><a name="v:runRWS" class="def">runRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (a, s, w)</p><div class="doc"><p>Unwrap an RWS computation as a function.
(The inverse of <code><a href="Control-Monad-RWS-Strict.html#v:rws">rws</a></code>.)
</p></div></div><div class="top"><p class="src"><a name="v:evalRWS" class="def">evalRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (a, w)</p></div><div class="top"><p class="src"><a name="v:execRWS" class="def">execRWS</a> :: <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> r -> s -> (s, w)</p></div><div class="top"><p class="src"><a name="v:mapRWS" class="def">mapRWS</a> :: ((a, s, w) -> (b, s, w')) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w' s b</p></div><div class="top"><p class="src"><a name="v:withRWS" class="def">withRWS</a> :: (r' -> s -> (r, s)) -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r w s a -> <a href="Control-Monad-RWS-Strict.html#t:RWS">RWS</a> r' w s a</p></div><h1 id="g:2">The RWST monad transformer
</h1><div class="top"><p class="src"><span class="keyword">newtype</span> <a name="t:RWST" class="def">RWST</a> r w s m a </p><div class="doc"><p>A monad transformer adding reading an environment of type <code>r</code>,
collecting an output of type <code>w</code> and updating a state of type <code>s</code>
to an inner monad <code>m</code>.
</p></div><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><a name="v:RWST" class="def">RWST</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:runRWST" class="def">runRWST</a> :: r -> s -> m (a, s, w)</dt><dd class="doc empty"> </dd></dl><div class="clear"></div></div></td></tr></table></div><div class="subs instances"><p id="control.i:RWST" class="caption collapser" onclick="toggleSection('i:RWST')">Instances</p><div id="section.i:RWST" class="show"><table><tr><td class="src">(<a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m) => <a href="Control-Monad-RWS-Class.html#t:MonadRWS">MonadRWS</a> r w s (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m) => <a href="Control-Monad-Writer-Class.html#t:MonadWriter">MonadWriter</a> w (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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:Monad">Monad</a> m, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html#t:Monoid">Monoid</a> w) => <a href="Control-Monad-State-Class.html#t:MonadState">MonadState</a> s (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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:Monad">Monad</a> m, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html#t:Monoid">Monoid</a> w) => <a href="Control-Monad-Reader-Class.html#t:MonadReader">MonadReader</a> r (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="Control-Monad-Error-Class.html#t:MonadError">MonadError</a> e m) => <a href="Control-Monad-Error-Class.html#t:MonadError">MonadError</a> e (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w => <a href="/usr/share/doc/ghc/html/libraries/transformers-0.2.2.0/Control-Monad-Trans-Class.html#t:MonadTrans">MonadTrans</a> (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s)</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> w, <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="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad-Fix.html#t:MonadFix">MonadFix</a> m) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad-Fix.html#t:MonadFix">MonadFix</a> (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> m) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:MonadPlus">MonadPlus</a> (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <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="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <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:MonadPlus">MonadPlus</a> m) => <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Applicative.html#t:Alternative">Alternative</a> (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <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="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s 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/Data-Monoid.html#t:Monoid">Monoid</a> w, <a href="Control-Monad-Cont-Class.html#t:MonadCont">MonadCont</a> m) => <a href="Control-Monad-Cont-Class.html#t:MonadCont">MonadCont</a> (<a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m)</td><td class="doc empty"> </td></tr></table></div></div></div><div class="top"><p class="src"><a name="v:evalRWST" class="def">evalRWST</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> r -> s -> m (a, w)</p></div><div class="top"><p class="src"><a name="v:execRWST" class="def">execRWST</a> :: <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html#t:Monad">Monad</a> m => <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> r -> s -> m (s, w)</p></div><div class="top"><p class="src"><a name="v:mapRWST" class="def">mapRWST</a> :: (m (a, s, w) -> n (b, s, w')) -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w' s n b</p></div><div class="top"><p class="src"><a name="v:withRWST" class="def">withRWST</a> :: (r' -> s -> (r, s)) -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r w s m a -> <a href="Control-Monad-RWS-Strict.html#t:RWST">RWST</a> r' w s m a</p></div><h1 id="g:3">Strict Reader-writer-state monads
</h1><div class="top"><p class="src">module <a href="Control-Monad-RWS-Class.html">Control.Monad.RWS.Class</a></p></div><div class="top"><p class="src">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad.html">Control.Monad</a></p></div><div class="top"><p class="src">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Control-Monad-Fix.html">Control.Monad.Fix</a></p></div><div class="top"><p class="src">module <a href="Control-Monad-Trans.html">Control.Monad.Trans</a></p></div><div class="top"><p class="src">module <a href="/usr/share/doc/ghc/html/libraries/base-4.3.1.0/Data-Monoid.html">Data.Monoid</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>
