<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ --> <title>src/Language/Haskell/Exts/Extension.hs</title> <link type='text/css' rel='stylesheet' href='hscolour.css' /> </head> <body> <pre><a name="line-1"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span> <a name="line-2"></a><span class='hs-comment'>-- |</span> <a name="line-3"></a><span class='hs-comment'>-- Module : Language.Haskell.Exts.Extension</span> <a name="line-4"></a><span class='hs-comment'>-- Copyright : (c) Niklas Broberg 2009</span> <a name="line-5"></a><span class='hs-comment'>-- License : BSD-style (see the file LICENSE.txt)</span> <a name="line-6"></a><span class='hs-comment'>--</span> <a name="line-7"></a><span class='hs-comment'>-- Maintainer : Niklas Broberg, d00nibro@chalmers.se</span> <a name="line-8"></a><span class='hs-comment'>-- Stability : transient</span> <a name="line-9"></a><span class='hs-comment'>-- Portability : portable</span> <a name="line-10"></a><span class='hs-comment'>--</span> <a name="line-11"></a><span class='hs-comment'>-- This entire module should be replaced with</span> <a name="line-12"></a><span class='hs-comment'>-- Language.Haskell.Extension from cabal, but we must</span> <a name="line-13"></a><span class='hs-comment'>-- wait for a release of cabal that includes the</span> <a name="line-14"></a><span class='hs-comment'>-- 'XmlSyntax' and 'RegularPatterns' extensions.</span> <a name="line-15"></a><span class='hs-comment'>--</span> <a name="line-16"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span> <a name="line-17"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Language</span><span class='hs-varop'>.</span><span class='hs-conid'>Haskell</span><span class='hs-varop'>.</span><span class='hs-conid'>Exts</span><span class='hs-varop'>.</span><span class='hs-conid'>Extension</span> <span class='hs-layout'>(</span> <a name="line-18"></a> <span class='hs-comment'>-- * Extensions</span> <a name="line-19"></a> <span class='hs-conid'>Extension</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>classifyExtension</span><span class='hs-layout'>,</span> <span class='hs-varid'>impliesExts</span><span class='hs-layout'>,</span> <a name="line-20"></a> <a name="line-21"></a> <span class='hs-comment'>-- * Extension groups</span> <a name="line-22"></a> <span class='hs-varid'>glasgowExts</span><span class='hs-layout'>,</span> <span class='hs-varid'>knownExtensions</span> <a name="line-23"></a> <a name="line-24"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-25"></a> <a name="line-26"></a> <a name="line-27"></a><a name="Extension"></a><span class='hs-comment'>-- | This datatype is a copy of the one in Cabal's Language.Haskell.Extension module.</span> <a name="line-28"></a><a name="Extension"></a><span class='hs-comment'>-- The intention is to eventually import it from Cabal, but we need to wait for</span> <a name="line-29"></a><a name="Extension"></a><span class='hs-comment'>-- the next release of Cabal which includes XmlSyntax and RegularPatterns.</span> <a name="line-30"></a><a name="Extension"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Extension</span> <a name="line-31"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>OverlappingInstances</span> <a name="line-32"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>UndecidableInstances</span> <a name="line-33"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>IncoherentInstances</span> <a name="line-34"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RecursiveDo</span> <a name="line-35"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ParallelListComp</span> <a name="line-36"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>MultiParamTypeClasses</span> <a name="line-37"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NoMonomorphismRestriction</span> <a name="line-38"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>FunctionalDependencies</span> <a name="line-39"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ExplicitForall</span> <a name="line-40"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Rank2Types</span> <a name="line-41"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RankNTypes</span> <a name="line-42"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PolymorphicComponents</span> <a name="line-43"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ExistentialQuantification</span> <a name="line-44"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ScopedTypeVariables</span> <a name="line-45"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ImplicitParams</span> <a name="line-46"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>FlexibleContexts</span> <a name="line-47"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>FlexibleInstances</span> <a name="line-48"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>EmptyDataDecls</span> <a name="line-49"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>CPP</span> <a name="line-50"></a> <a name="line-51"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>KindSignatures</span> <a name="line-52"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>BangPatterns</span> <a name="line-53"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TypeSynonymInstances</span> <a name="line-54"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TemplateHaskell</span> <a name="line-55"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ForeignFunctionInterface</span> <a name="line-56"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Arrows</span> <a name="line-57"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Generics</span> <a name="line-58"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NoImplicitPrelude</span> <a name="line-59"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NamedFieldPuns</span> <a name="line-60"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PatternGuards</span> <a name="line-61"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>GeneralizedNewtypeDeriving</span> <a name="line-62"></a> <a name="line-63"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ExtensibleRecords</span> <a name="line-64"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RestrictedTypeSynonyms</span> <a name="line-65"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>HereDocuments</span> <a name="line-66"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>MagicHash</span> <a name="line-67"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TypeFamilies</span> <a name="line-68"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>StandaloneDeriving</span> <a name="line-69"></a> <a name="line-70"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>UnicodeSyntax</span> <a name="line-71"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PatternSignatures</span> <a name="line-72"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>UnliftedFFITypes</span> <a name="line-73"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>LiberalTypeSynonyms</span> <a name="line-74"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TypeOperators</span> <a name="line-75"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RecordWildCards</span> <a name="line-76"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RecordPuns</span> <span class='hs-comment'>-- should be deprecated</span> <a name="line-77"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>DisambiguateRecordFields</span> <a name="line-78"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>OverloadedStrings</span> <a name="line-79"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>GADTs</span> <a name="line-80"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>MonoPatBinds</span> <a name="line-81"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NoMonoPatBinds</span> <span class='hs-comment'>-- should be deprecated</span> <a name="line-82"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RelaxedPolyRec</span> <a name="line-83"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ExtendedDefaultRules</span> <a name="line-84"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>UnboxedTuples</span> <a name="line-85"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>DeriveDataTypeable</span> <a name="line-86"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ConstrainedClassMethods</span> <a name="line-87"></a> <a name="line-88"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PackageImports</span> <a name="line-89"></a> <a name="line-90"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ImpredicativeTypes</span> <a name="line-91"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NewQualifiedOperators</span> <a name="line-92"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PostfixOperators</span> <a name="line-93"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>QuasiQuotes</span> <a name="line-94"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TransformListComp</span> <a name="line-95"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ViewPatterns</span> <a name="line-96"></a> <a name="line-97"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>XmlSyntax</span> <a name="line-98"></a> <a name="line-99"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RegularPatterns</span> <a name="line-100"></a> <a name="line-101"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>TupleSections</span> <a name="line-102"></a> <a name="line-103"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>UnknownExtension</span> <span class='hs-conid'>String</span> <a name="line-104"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Ord</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>,</span> <span class='hs-conid'>Read</span><span class='hs-layout'>)</span> <a name="line-105"></a> <a name="line-106"></a> <a name="line-107"></a><a name="impliesExts"></a><span class='hs-comment'>-- | Certain extensions imply other extensions, and this function</span> <a name="line-108"></a><span class='hs-comment'>-- makes the implication explicit. This also handles deprecated</span> <a name="line-109"></a><span class='hs-comment'>-- extensions, which imply their replacements.</span> <a name="line-110"></a><span class='hs-comment'>-- The returned valued is the transitive closure of implied</span> <a name="line-111"></a><span class='hs-comment'>-- extensions.</span> <a name="line-112"></a><span class='hs-definition'>impliesExts</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Extension</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Extension</span><span class='hs-keyglyph'>]</span> <a name="line-113"></a><span class='hs-definition'>impliesExts</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <a name="line-114"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>go</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <a name="line-115"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>es</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>concatMap</span> <span class='hs-varid'>implE</span> <span class='hs-varid'>es</span> <a name="line-116"></a> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>filter</span> <span class='hs-layout'>(</span><span class='hs-varid'>not</span> <span class='hs-varop'>.</span> <span class='hs-varid'>flip</span> <span class='hs-varid'>elem</span> <span class='hs-varid'>es</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <a name="line-117"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>es</span> <span class='hs-varop'>++</span> <span class='hs-varid'>go</span> <span class='hs-varid'>ys</span> <a name="line-118"></a> <a name="line-119"></a> <span class='hs-varid'>implE</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>e</span> <span class='hs-keyword'>of</span> <a name="line-120"></a> <span class='hs-conid'>TypeFamilies</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>KindSignatures</span><span class='hs-keyglyph'>]</span> <a name="line-121"></a> <span class='hs-conid'>ScopedTypeVariables</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>TypeOperators</span><span class='hs-layout'>,</span> <span class='hs-conid'>ExplicitForall</span><span class='hs-keyglyph'>]</span> <a name="line-122"></a> <span class='hs-conid'>XmlSyntax</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>RegularPatterns</span><span class='hs-keyglyph'>]</span> <a name="line-123"></a> <span class='hs-conid'>RegularPatterns</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>PatternGuards</span><span class='hs-keyglyph'>]</span> <a name="line-124"></a> <span class='hs-conid'>RankNTypes</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Rank2Types</span><span class='hs-keyglyph'>]</span> <a name="line-125"></a> <span class='hs-conid'>Rank2Types</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>PolymorphicComponents</span><span class='hs-keyglyph'>]</span> <a name="line-126"></a> <span class='hs-conid'>PolymorphicComponents</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>ExplicitForall</span><span class='hs-keyglyph'>]</span> <a name="line-127"></a> <span class='hs-conid'>LiberalTypeSynonyms</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>ExplicitForall</span><span class='hs-keyglyph'>]</span> <a name="line-128"></a> <span class='hs-comment'>-- Deprecations</span> <a name="line-129"></a> <span class='hs-conid'>RecordPuns</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>NamedFieldPuns</span><span class='hs-keyglyph'>]</span> <a name="line-130"></a> <span class='hs-conid'>PatternSignatures</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>ScopedTypeVariables</span><span class='hs-keyglyph'>]</span> <a name="line-131"></a> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span> <a name="line-132"></a> <a name="line-133"></a><a name="glasgowExts"></a><span class='hs-comment'>-- | The list of extensions enabled by</span> <a name="line-134"></a><span class='hs-comment'>-- GHC's portmanteau -fglasgow-exts flag.</span> <a name="line-135"></a><span class='hs-definition'>glasgowExts</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Extension</span><span class='hs-keyglyph'>]</span> <a name="line-136"></a><span class='hs-definition'>glasgowExts</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span> <a name="line-137"></a> <span class='hs-conid'>ForeignFunctionInterface</span> <a name="line-138"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnliftedFFITypes</span> <a name="line-139"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>GADTs</span> <a name="line-140"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ImplicitParams</span> <a name="line-141"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ScopedTypeVariables</span> <a name="line-142"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnboxedTuples</span> <a name="line-143"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeSynonymInstances</span> <a name="line-144"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>StandaloneDeriving</span> <a name="line-145"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>DeriveDataTypeable</span> <a name="line-146"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FlexibleContexts</span> <a name="line-147"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FlexibleInstances</span> <a name="line-148"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ConstrainedClassMethods</span> <a name="line-149"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>MultiParamTypeClasses</span> <a name="line-150"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FunctionalDependencies</span> <a name="line-151"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>MagicHash</span> <a name="line-152"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PolymorphicComponents</span> <a name="line-153"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExistentialQuantification</span> <a name="line-154"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnicodeSyntax</span> <a name="line-155"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PostfixOperators</span> <a name="line-156"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PatternGuards</span> <a name="line-157"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>LiberalTypeSynonyms</span> <a name="line-158"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RankNTypes</span> <a name="line-159"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ImpredicativeTypes</span> <a name="line-160"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeOperators</span> <a name="line-161"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RecursiveDo</span> <a name="line-162"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ParallelListComp</span> <a name="line-163"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>EmptyDataDecls</span> <a name="line-164"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>KindSignatures</span> <a name="line-165"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>GeneralizedNewtypeDeriving</span> <a name="line-166"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeFamilies</span> <a name="line-167"></a> <span class='hs-keyglyph'>]</span> <a name="line-168"></a> <a name="line-169"></a><a name="knownExtensions"></a><span class='hs-comment'>-- | List of all known extensions. Poor man's 'Enum' instance</span> <a name="line-170"></a><span class='hs-comment'>-- (we can't enum with the 'UnknownExtension' constructor).</span> <a name="line-171"></a><span class='hs-definition'>knownExtensions</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Extension</span><span class='hs-keyglyph'>]</span> <a name="line-172"></a><span class='hs-definition'>knownExtensions</span> <span class='hs-keyglyph'>=</span> <a name="line-173"></a> <span class='hs-keyglyph'>[</span> <span class='hs-conid'>OverlappingInstances</span> <a name="line-174"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UndecidableInstances</span> <a name="line-175"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>IncoherentInstances</span> <a name="line-176"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RecursiveDo</span> <a name="line-177"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ParallelListComp</span> <a name="line-178"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>MultiParamTypeClasses</span> <a name="line-179"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>NoMonomorphismRestriction</span> <a name="line-180"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FunctionalDependencies</span> <a name="line-181"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExplicitForall</span> <a name="line-182"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Rank2Types</span> <a name="line-183"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RankNTypes</span> <a name="line-184"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PolymorphicComponents</span> <a name="line-185"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExistentialQuantification</span> <a name="line-186"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ScopedTypeVariables</span> <a name="line-187"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ImplicitParams</span> <a name="line-188"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FlexibleContexts</span> <a name="line-189"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>FlexibleInstances</span> <a name="line-190"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>EmptyDataDecls</span> <a name="line-191"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>CPP</span> <a name="line-192"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>KindSignatures</span> <a name="line-193"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>BangPatterns</span> <a name="line-194"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeSynonymInstances</span> <a name="line-195"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TemplateHaskell</span> <a name="line-196"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ForeignFunctionInterface</span> <a name="line-197"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Arrows</span> <a name="line-198"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Generics</span> <a name="line-199"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>NoImplicitPrelude</span> <a name="line-200"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>NamedFieldPuns</span> <a name="line-201"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PatternGuards</span> <a name="line-202"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>GeneralizedNewtypeDeriving</span> <a name="line-203"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExtensibleRecords</span> <a name="line-204"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RestrictedTypeSynonyms</span> <a name="line-205"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>HereDocuments</span> <a name="line-206"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>MagicHash</span> <a name="line-207"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeFamilies</span> <a name="line-208"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>StandaloneDeriving</span> <a name="line-209"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnicodeSyntax</span> <a name="line-210"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PatternSignatures</span> <a name="line-211"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnliftedFFITypes</span> <a name="line-212"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>LiberalTypeSynonyms</span> <a name="line-213"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TypeOperators</span> <a name="line-214"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RecordWildCards</span> <a name="line-215"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RecordPuns</span> <span class='hs-comment'>-- should be deprecated</span> <a name="line-216"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>DisambiguateRecordFields</span> <a name="line-217"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>OverloadedStrings</span> <a name="line-218"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>GADTs</span> <a name="line-219"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>MonoPatBinds</span> <a name="line-220"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>NoMonoPatBinds</span> <span class='hs-comment'>-- should be deprecated</span> <a name="line-221"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RelaxedPolyRec</span> <a name="line-222"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExtendedDefaultRules</span> <a name="line-223"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>UnboxedTuples</span> <a name="line-224"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>DeriveDataTypeable</span> <a name="line-225"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ConstrainedClassMethods</span> <a name="line-226"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PackageImports</span> <a name="line-227"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ImpredicativeTypes</span> <a name="line-228"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>NewQualifiedOperators</span> <a name="line-229"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>PostfixOperators</span> <a name="line-230"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>QuasiQuotes</span> <a name="line-231"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TransformListComp</span> <a name="line-232"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ViewPatterns</span> <a name="line-233"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>XmlSyntax</span> <a name="line-234"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RegularPatterns</span> <a name="line-235"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>TupleSections</span> <a name="line-236"></a> <span class='hs-keyglyph'>]</span> <a name="line-237"></a> <a name="line-238"></a> <a name="line-239"></a> <a name="line-240"></a><a name="classifyExtension"></a><span class='hs-comment'>-- | A clever version of read that returns an 'UnknownExtension'</span> <a name="line-241"></a><span class='hs-comment'>-- if the string is not recognised.</span> <a name="line-242"></a><span class='hs-definition'>classifyExtension</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Extension</span> <a name="line-243"></a><span class='hs-definition'>classifyExtension</span> <span class='hs-varid'>str</span> <a name="line-244"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>readsPrec</span> <span class='hs-num'>0</span> <span class='hs-varid'>str</span> <span class='hs-keyword'>of</span> <a name="line-245"></a> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-str'>""</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>e</span> <a name="line-246"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>UnknownExtension</span> <span class='hs-varid'>str</span> </pre></body> </html>
