<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!--Rendered using the Haskell Html Library v0.2--> <HTML ><HEAD ><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8" ><TITLE >Maybes</TITLE ><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css" ><SCRIPT SRC="haddock-util.js" TYPE="text/javascript" ></SCRIPT ><SCRIPT TYPE="text/javascript" >window.onload = function () {setSynopsis("mini_Maybes.html")};</SCRIPT ></HEAD ><BODY ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="topbar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" " ></TD ><TD CLASS="title" >ghc-6.12.3: The GHC API</TD ><TD CLASS="topbut" ><A HREF="src/Maybes.html" >Source code</A ></TD ><TD CLASS="topbut" ><A HREF="index.html" >Contents</A ></TD ><TD CLASS="topbut" ><A HREF="doc-index.html" >Index</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="modulebar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><FONT SIZE="6" >Maybes</FONT ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Synopsis</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" >module <A HREF="../base-4.2.0.2/Data-Maybe.html" >Data.Maybe</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >data</SPAN > <A HREF="#t%3AMaybeErr" >MaybeErr</A > err val </TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" >= <A HREF="#v%3ASucceeded" >Succeeded</A > val</TD ></TR ><TR ><TD CLASS="decl" >| <A HREF="#v%3AFailed" >Failed</A > err</TD ></TR ></TABLE ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AfailME" >failME</A > :: err -> <A HREF="Maybes.html#t%3AMaybeErr" >MaybeErr</A > err val</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AisSuccess" >isSuccess</A > :: <A HREF="Maybes.html#t%3AMaybeErr" >MaybeErr</A > err val -> <A HREF="../base-4.2.0.2/Data-Bool.html#t%3ABool" >Bool</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AfmapM_maybe" >fmapM_maybe</A > :: <A HREF="../base-4.2.0.2/Control-Monad.html#t%3AMonad" >Monad</A > m => (a -> m b) -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> m (<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > b)</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AorElse" >orElse</A > :: <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> a -> a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmapCatMaybes" >mapCatMaybes</A > :: (a -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > b) -> [a] -> [b]</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AallMaybes" >allMaybes</A > :: [<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a] -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > [a]</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AfirstJust" >firstJust</A > :: [<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a] -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AexpectJust" >expectJust</A > :: <A HREF="../base-4.2.0.2/Data-Char.html#t%3AString" >String</A > -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmaybeToBool" >maybeToBool</A > :: <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> <A HREF="../base-4.2.0.2/Data-Bool.html#t%3ABool" >Bool</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >newtype</SPAN > <A HREF="#t%3AMaybeT" >MaybeT</A > m a = <A HREF="#v%3AMaybeT" >MaybeT</A > {<TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="recfield" ><A HREF="#v%3ArunMaybeT" >runMaybeT</A > :: m (<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a)</TD ></TR ></TABLE >}</TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Documentation</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" >module <A HREF="../base-4.2.0.2/Data-Maybe.html" >Data.Maybe</A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><SPAN CLASS="keyword" >data</SPAN > <A NAME="t:MaybeErr" ><A NAME="t%3AMaybeErr" ></A ></A ><B >MaybeErr</B > err val </TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#MaybeErr" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="section4" >Constructors</TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="arg" ><A NAME="v:Succeeded" ><A NAME="v%3ASucceeded" ></A ></A ><B >Succeeded</B > val</TD ><TD CLASS="rdoc" ></TD ></TR ><TR ><TD CLASS="arg" ><A NAME="v:Failed" ><A NAME="v%3AFailed" ></A ></A ><B >Failed</B > err</TD ><TD CLASS="rdoc" ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="section4" ><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:MaybeErr')" ALT="show/hide" > Instances</TD ></TR ><TR ><TD CLASS="body" ><DIV ID="i:MaybeErr" STYLE="display:block;" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="../base-4.2.0.2/Control-Monad.html#t%3AMonad" >Monad</A > (<A HREF="Maybes.html#t%3AMaybeErr" >MaybeErr</A > err)</TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:failME" ><A NAME="v%3AfailME" ></A ></A ><B >failME</B > :: err -> <A HREF="Maybes.html#t%3AMaybeErr" >MaybeErr</A > err val</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#failME" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:isSuccess" ><A NAME="v%3AisSuccess" ></A ></A ><B >isSuccess</B > :: <A HREF="Maybes.html#t%3AMaybeErr" >MaybeErr</A > err val -> <A HREF="../base-4.2.0.2/Data-Bool.html#t%3ABool" >Bool</A ></TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#isSuccess" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:fmapM_maybe" ><A NAME="v%3AfmapM_maybe" ></A ></A ><B >fmapM_maybe</B > :: <A HREF="../base-4.2.0.2/Control-Monad.html#t%3AMonad" >Monad</A > m => (a -> m b) -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> m (<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > b)</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#fmapM_maybe" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:orElse" ><A NAME="v%3AorElse" ></A ></A ><B >orElse</B > :: <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> a -> a</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#orElse" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:mapCatMaybes" ><A NAME="v%3AmapCatMaybes" ></A ></A ><B >mapCatMaybes</B > :: (a -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > b) -> [a] -> [b]</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#mapCatMaybes" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:allMaybes" ><A NAME="v%3AallMaybes" ></A ></A ><B >allMaybes</B > :: [<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a] -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > [a]</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#allMaybes" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="doc" >Collects a list of <TT >Justs</TT > into a single <TT >Just</TT >, returning <TT >Nothing</TT > if there are any <TT >Nothings</TT >. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:firstJust" ><A NAME="v%3AfirstJust" ></A ></A ><B >firstJust</B > :: [<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a] -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#firstJust" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="doc" >Takes a list of <TT >Maybes</TT > and returns the first <TT >Just</TT > if there is one, or <TT >Nothing</TT > otherwise. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:expectJust" ><A NAME="v%3AexpectJust" ></A ></A ><B >expectJust</B > :: <A HREF="../base-4.2.0.2/Data-Char.html#t%3AString" >String</A > -> <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> a</TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#expectJust" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:maybeToBool" ><A NAME="v%3AmaybeToBool" ></A ></A ><B >maybeToBool</B > :: <A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> <A HREF="../base-4.2.0.2/Data-Bool.html#t%3ABool" >Bool</A ></TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#maybeToBool" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><SPAN CLASS="keyword" >newtype</SPAN > <A NAME="t:MaybeT" ><A NAME="t%3AMaybeT" ></A ></A ><B >MaybeT</B > m a </TD ><TD CLASS="declbut" ><A HREF="src/Maybes.html#MaybeT" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="section4" >Constructors</TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="5" CELLPADDING="0" ><TR ><TD CLASS="arg" ><A NAME="v:MaybeT" ><A NAME="v%3AMaybeT" ></A ></A ><B >MaybeT</B ></TD ><TD CLASS="rdoc" ></TD ></TR ><TR ><TD CLASS="body" COLSPAN="2" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="arg" ><A NAME="v:runMaybeT" ><A NAME="v%3ArunMaybeT" ></A ></A ><B >runMaybeT</B > :: m (<A HREF="../base-4.2.0.2/Data-Maybe.html#t%3AMaybe" >Maybe</A > a)</TD ><TD CLASS="rdoc" ></TD ></TR ></TABLE ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="section4" ><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:MaybeT')" ALT="show/hide" > Instances</TD ></TR ><TR ><TD CLASS="body" ><DIV ID="i:MaybeT" STYLE="display:block;" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="../base-4.2.0.2/Control-Monad.html#t%3AMonad" >Monad</A > m => <A HREF="../base-4.2.0.2/Control-Monad.html#t%3AMonad" >Monad</A > (<A HREF="Maybes.html#t%3AMaybeT" >MaybeT</A > m)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="../base-4.2.0.2/Control-Monad.html#t%3AFunctor" >Functor</A > m => <A HREF="../base-4.2.0.2/Control-Monad.html#t%3AFunctor" >Functor</A > (<A HREF="Maybes.html#t%3AMaybeT" >MaybeT</A > m)</TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="botbar" >Produced by <A HREF="http://www.haskell.org/haddock/" >Haddock</A > version 2.6.1</TD ></TR ></TABLE ></BODY ></HTML >