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<title>Test/QuickCheck/Property.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE FlexibleInstances #-}</span>
<a name="line-2"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>Property</span> <span class='hs-keyword'>where</span>
<a name="line-3"></a>
<a name="line-4"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-5"></a><span class='hs-comment'>-- imports</span>
<a name="line-6"></a>
<a name="line-7"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>Gen</span>
<a name="line-8"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>Arbitrary</span>
<a name="line-9"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-layout'>(</span> <span class='hs-varid'>showErr</span><span class='hs-layout'>,</span> <span class='hs-varid'>putLine</span> <span class='hs-layout'>)</span>
<a name="line-10"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span>
<a name="line-11"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Test</span><span class='hs-varop'>.</span><span class='hs-conid'>QuickCheck</span><span class='hs-varop'>.</span><span class='hs-conid'>State</span>
<a name="line-12"></a>
<a name="line-13"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Concurrent</span>
<a name="line-14"></a> <span class='hs-layout'>(</span> <span class='hs-varid'>forkIO</span>
<a name="line-15"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>threadDelay</span>
<a name="line-16"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>killThread</span>
<a name="line-17"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>newEmptyMVar</span>
<a name="line-18"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>takeMVar</span>
<a name="line-19"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>putMVar</span>
<a name="line-20"></a> <span class='hs-layout'>)</span>
<a name="line-21"></a>
<a name="line-22"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span>
<a name="line-23"></a> <span class='hs-layout'>(</span> <span class='hs-varid'>hFlush</span>
<a name="line-24"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>stdout</span>
<a name="line-25"></a> <span class='hs-layout'>)</span>
<a name="line-26"></a>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Timeout</span><span class='hs-layout'>(</span><span class='hs-varid'>timeout</span><span class='hs-layout'>)</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Maybe</span>
<a name="line-29"></a>
<a name="line-30"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-31"></a><span class='hs-comment'>-- fixities</span>
<a name="line-32"></a>
<a name="line-33"></a><span class='hs-keyword'>infixr</span> <span class='hs-num'>0</span> <span class='hs-varop'>==></span>
<a name="line-34"></a><span class='hs-keyword'>infixr</span> <span class='hs-num'>1</span> <span class='hs-varop'>.&.</span>
<a name="line-35"></a><span class='hs-keyword'>infixr</span> <span class='hs-num'>1</span> <span class='hs-varop'>.&&.</span>
<a name="line-36"></a><span class='hs-keyword'>infixr</span> <span class='hs-num'>1</span> <span class='hs-varop'>.||.</span>
<a name="line-37"></a>
<a name="line-38"></a><span class='hs-comment'>-- The story for exception handling:</span>
<a name="line-39"></a><span class='hs-comment'>--</span>
<a name="line-40"></a><span class='hs-comment'>-- To avoid insanity, we have rules about which terms can throw</span>
<a name="line-41"></a><span class='hs-comment'>-- exceptions when we evaluate them:</span>
<a name="line-42"></a><span class='hs-comment'>-- * A rose tree must evaluate to WHNF without throwing an exception</span>
<a name="line-43"></a><span class='hs-comment'>-- * The 'ok' component of a Result must evaluate to Just True or</span>
<a name="line-44"></a><span class='hs-comment'>-- Just False or Nothing rather than raise an exception</span>
<a name="line-45"></a><span class='hs-comment'>-- * IORose _ must never throw an exception when executed</span>
<a name="line-46"></a><span class='hs-comment'>--</span>
<a name="line-47"></a><span class='hs-comment'>-- Both rose trees and Results may loop when we evaluate them, though,</span>
<a name="line-48"></a><span class='hs-comment'>-- so we have to be careful not to force them unnecessarily.</span>
<a name="line-49"></a><span class='hs-comment'>--</span>
<a name="line-50"></a><span class='hs-comment'>-- We also have to be careful when we use fmap or >>= in the Rose</span>
<a name="line-51"></a><span class='hs-comment'>-- monad that the function we supply is total, or else use</span>
<a name="line-52"></a><span class='hs-comment'>-- protectResults afterwards to install exception handlers. The</span>
<a name="line-53"></a><span class='hs-comment'>-- mapResult function on Properties installs an exception handler for</span>
<a name="line-54"></a><span class='hs-comment'>-- us, though.</span>
<a name="line-55"></a><span class='hs-comment'>--</span>
<a name="line-56"></a><span class='hs-comment'>-- Of course, the user is free to write "error "ha ha" :: Result" if</span>
<a name="line-57"></a><span class='hs-comment'>-- they feel like it. We have to make sure that any user-supplied Rose</span>
<a name="line-58"></a><span class='hs-comment'>-- Results or Results get wrapped in exception handlers, which we do by:</span>
<a name="line-59"></a><span class='hs-comment'>-- * Making the 'property' function install an exception handler</span>
<a name="line-60"></a><span class='hs-comment'>-- round its argument. This function always gets called in the</span>
<a name="line-61"></a><span class='hs-comment'>-- right places, because all our Property-accepting functions are</span>
<a name="line-62"></a><span class='hs-comment'>-- actually polymorphic over the Testable class so they have to</span>
<a name="line-63"></a><span class='hs-comment'>-- call 'property'.</span>
<a name="line-64"></a><span class='hs-comment'>-- * Installing an exception handler round a Result before we put it</span>
<a name="line-65"></a><span class='hs-comment'>-- in a rose tree (the only place Results can end up).</span>
<a name="line-66"></a>
<a name="line-67"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-68"></a><span class='hs-comment'>-- * Property and Testable types</span>
<a name="line-69"></a>
<a name="line-70"></a><a name="Property"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Property</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Gen</span> <span class='hs-conid'>Prop</span>
<a name="line-71"></a>
<a name="line-72"></a><a name="Testable"></a><span class='hs-comment'>-- | The class of things which can be tested, i.e. turned into a property.</span>
<a name="line-73"></a><a name="Testable"></a><span class='hs-keyword'>class</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyword'>where</span>
<a name="line-74"></a> <span class='hs-varid'>property</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-75"></a>
<a name="line-76"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Testable</span> <span class='hs-conid'>()</span> <span class='hs-keyword'>where</span>
<a name="line-77"></a> <span class='hs-varid'>property</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>property</span> <span class='hs-varid'>rejected</span>
<a name="line-78"></a>
<a name="line-79"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Testable</span> <span class='hs-conid'>Bool</span> <span class='hs-keyword'>where</span>
<a name="line-80"></a> <span class='hs-varid'>property</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>property</span> <span class='hs-varop'>.</span> <span class='hs-varid'>liftBool</span>
<a name="line-81"></a>
<a name="line-82"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Testable</span> <span class='hs-conid'>Result</span> <span class='hs-keyword'>where</span>
<a name="line-83"></a> <span class='hs-varid'>property</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>MkProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>protectResults</span> <span class='hs-varop'>.</span> <span class='hs-varid'>return</span>
<a name="line-84"></a>
<a name="line-85"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Testable</span> <span class='hs-conid'>Prop</span> <span class='hs-keyword'>where</span>
<a name="line-86"></a> <span class='hs-varid'>property</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>MkProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>ioRose</span> <span class='hs-varop'>.</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>r</span>
<a name="line-87"></a>
<a name="line-88"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Testable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Gen</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-89"></a> <span class='hs-varid'>property</span> <span class='hs-varid'>mp</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mp</span><span class='hs-layout'>;</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p</span>
<a name="line-90"></a>
<a name="line-91"></a><a name="morallyDubiousIOProperty"></a><span class='hs-comment'>-- | Do I/O inside a property. This can obviously lead to unrepeatable</span>
<a name="line-92"></a><span class='hs-comment'>-- testcases, so use with care.</span>
<a name="line-93"></a><span class='hs-definition'>morallyDubiousIOProperty</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-94"></a><span class='hs-definition'>morallyDubiousIOProperty</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>ioRose</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>unProp</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>promote</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>property</span>
<a name="line-95"></a>
<a name="line-96"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Arbitrary</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Testable</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-97"></a> <span class='hs-varid'>property</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>forAllShrink</span> <span class='hs-varid'>arbitrary</span> <span class='hs-varid'>shrink</span> <span class='hs-varid'>f</span>
<a name="line-98"></a>
<a name="line-99"></a><a name="protect"></a><span class='hs-comment'>-- ** Exception handling</span>
<a name="line-100"></a><span class='hs-definition'>protect</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>AnException</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-101"></a><span class='hs-definition'>protect</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>either</span> <span class='hs-varid'>f</span> <span class='hs-varid'>id</span> <span class='hs-varop'>`fmap`</span> <span class='hs-varid'>tryEvaluateIO</span> <span class='hs-varid'>x</span>
<a name="line-102"></a>
<a name="line-103"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-104"></a><span class='hs-comment'>-- ** Type Prop</span>
<a name="line-105"></a>
<a name="line-106"></a><a name="Prop"></a><span class='hs-keyword'>newtype</span> <span class='hs-conid'>Prop</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MkProp</span><span class='hs-layout'>{</span> <span class='hs-varid'>unProp</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-layout'>}</span>
<a name="line-107"></a>
<a name="line-108"></a><span class='hs-comment'>-- ** type Rose</span>
<a name="line-109"></a>
<a name="line-110"></a><a name="Rose"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>IORose</span> <span class='hs-layout'>(</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-111"></a><a name="ioRose"></a><span class='hs-comment'>-- Only use IORose if you know that the argument is not going to throw an exception!</span>
<a name="line-112"></a><span class='hs-comment'>-- Otherwise, try ioRose.</span>
<a name="line-113"></a><span class='hs-definition'>ioRose</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span>
<a name="line-114"></a><span class='hs-definition'>ioRose</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-varop'>.</span> <span class='hs-varid'>protectRose</span>
<a name="line-115"></a>
<a name="line-116"></a><a name="joinRose"></a><span class='hs-definition'>joinRose</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Rose</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span>
<a name="line-117"></a><span class='hs-definition'>joinRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>IORose</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>joinRose</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span>
<a name="line-118"></a><span class='hs-definition'>joinRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>IORose</span> <span class='hs-varid'>rm</span><span class='hs-layout'>)</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>rm</span><span class='hs-layout'>;</span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>joinRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>r</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-119"></a><span class='hs-definition'>joinRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>x</span> <span class='hs-varid'>ts</span><span class='hs-layout'>)</span> <span class='hs-varid'>tts</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-120"></a> <span class='hs-comment'>-- first shrinks outer quantification; makes most sense</span>
<a name="line-121"></a> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-varid'>joinRose</span> <span class='hs-varid'>tts</span> <span class='hs-varop'>++</span> <span class='hs-varid'>ts</span><span class='hs-layout'>)</span>
<a name="line-122"></a> <span class='hs-comment'>-- first shrinks inner quantification</span>
<a name="line-123"></a> <span class='hs-comment'>--MkRose x (ts ++ map joinRose tts)</span>
<a name="line-124"></a>
<a name="line-125"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Functor</span> <span class='hs-conid'>Rose</span> <span class='hs-keyword'>where</span>
<a name="line-126"></a> <span class='hs-comment'>-- f must be total</span>
<a name="line-127"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>IORose</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span>
<a name="line-128"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>x</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MkRose</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>rs</span> <span class='hs-keyglyph'>]</span>
<a name="line-129"></a>
<a name="line-130"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Monad</span> <span class='hs-conid'>Rose</span> <span class='hs-keyword'>where</span>
<a name="line-131"></a> <span class='hs-varid'>return</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>x</span> <span class='hs-conid'>[]</span>
<a name="line-132"></a> <span class='hs-comment'>-- k must be total</span>
<a name="line-133"></a> <span class='hs-varid'>m</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>joinRose</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>k</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span>
<a name="line-134"></a>
<a name="line-135"></a><a name="reduceRose"></a><span class='hs-comment'>-- Execute the "IORose" bits of a rose tree, returning a tree</span>
<a name="line-136"></a><span class='hs-comment'>-- constructed by MkRose.</span>
<a name="line-137"></a><span class='hs-definition'>reduceRose</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span>
<a name="line-138"></a><span class='hs-definition'>reduceRose</span> <span class='hs-varid'>r</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varid'>r</span>
<a name="line-139"></a><span class='hs-definition'>reduceRose</span> <span class='hs-layout'>(</span><span class='hs-conid'>IORose</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>m</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>reduceRose</span>
<a name="line-140"></a>
<a name="line-141"></a><a name="onRose"></a><span class='hs-comment'>-- Apply a function to the outermost MkRose constructor of a rose tree.</span>
<a name="line-142"></a><span class='hs-comment'>-- The function must be total!</span>
<a name="line-143"></a><span class='hs-definition'>onRose</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-varid'>a</span>
<a name="line-144"></a><span class='hs-definition'>onRose</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>x</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>rs</span>
<a name="line-145"></a><span class='hs-definition'>onRose</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>IORose</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-varid'>onRose</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span>
<a name="line-146"></a>
<a name="line-147"></a><a name="protectRose"></a><span class='hs-comment'>-- Wrap a rose tree in an exception handler.</span>
<a name="line-148"></a><span class='hs-definition'>protectRose</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span>
<a name="line-149"></a><span class='hs-definition'>protectRose</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>protect</span> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-varid'>exception</span> <span class='hs-str'>"Exception"</span><span class='hs-layout'>)</span>
<a name="line-150"></a>
<a name="line-151"></a><a name="protectResults"></a><span class='hs-comment'>-- Wrap all the Results in a rose tree in exception handlers.</span>
<a name="line-152"></a><span class='hs-definition'>protectResults</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span>
<a name="line-153"></a><span class='hs-definition'>protectResults</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>onRose</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-varid'>rs</span> <span class='hs-keyglyph'>-></span>
<a name="line-154"></a> <span class='hs-conid'>IORose</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-155"></a> <span class='hs-varid'>y</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>protectResult</span> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-156"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>y</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-varid'>protectResults</span> <span class='hs-varid'>rs</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-157"></a>
<a name="line-158"></a><span class='hs-comment'>-- ** Result type</span>
<a name="line-159"></a>
<a name="line-160"></a><a name="Callback"></a><span class='hs-comment'>-- | Different kinds of callbacks</span>
<a name="line-161"></a><a name="Callback"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Callback</span>
<a name="line-162"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>PostTest</span> <span class='hs-conid'>CallbackKind</span> <span class='hs-layout'>(</span><span class='hs-conid'>State</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ Called just after a test</span>
<a name="line-163"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PostFinalFailure</span> <span class='hs-conid'>CallbackKind</span> <span class='hs-layout'>(</span><span class='hs-conid'>State</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ Called with the final failing test-case</span>
<a name="line-164"></a><a name="CallbackKind"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>CallbackKind</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Counterexample</span> <span class='hs-comment'>-- ^ Affected by the 'verbose' combinator</span>
<a name="line-165"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NotCounterexample</span> <span class='hs-comment'>-- ^ Not affected by the 'verbose' combinator</span>
<a name="line-166"></a>
<a name="line-167"></a><a name="Result"></a><span class='hs-comment'>-- | The result of a single test.</span>
<a name="line-168"></a><a name="Result"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Result</span>
<a name="line-169"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MkResult</span>
<a name="line-170"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Bool</span> <span class='hs-comment'>-- ^ result of the test case; Nothing = discard</span>
<a name="line-171"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>expect</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span> <span class='hs-comment'>-- ^ indicates what the expected result of the property is</span>
<a name="line-172"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ a message indicating what went wrong</span>
<a name="line-173"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>interrupted</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span> <span class='hs-comment'>-- ^ indicates if the test case was cancelled by pressing ^C</span>
<a name="line-174"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>stamp</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>String</span><span class='hs-layout'>,</span><span class='hs-conid'>Int</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ the collected values for this test case</span>
<a name="line-175"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Callback</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ the callbacks for this test case</span>
<a name="line-176"></a> <span class='hs-layout'>}</span>
<a name="line-177"></a>
<a name="line-178"></a><a name="result"></a><span class='hs-definition'>result</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Result</span>
<a name="line-179"></a><span class='hs-definition'>result</span> <span class='hs-keyglyph'>=</span>
<a name="line-180"></a> <span class='hs-conid'>MkResult</span>
<a name="line-181"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>undefined</span>
<a name="line-182"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>expect</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-183"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>""</span>
<a name="line-184"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>interrupted</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-185"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>stamp</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-186"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-187"></a> <span class='hs-layout'>}</span>
<a name="line-188"></a>
<a name="line-189"></a><a name="exception"></a><span class='hs-definition'>exception</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>AnException</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span>
<a name="line-190"></a><span class='hs-definition'>exception</span> <span class='hs-varid'>msg</span> <span class='hs-varid'>err</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>failed</span><span class='hs-layout'>{</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>msg</span> <span class='hs-varop'>++</span> <span class='hs-str'>": '"</span> <span class='hs-varop'>++</span> <span class='hs-varid'>showErr</span> <span class='hs-varid'>err</span> <span class='hs-varop'>++</span> <span class='hs-str'>"'"</span><span class='hs-layout'>,</span>
<a name="line-191"></a> <span class='hs-varid'>interrupted</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>isInterrupt</span> <span class='hs-varid'>err</span> <span class='hs-layout'>}</span>
<a name="line-192"></a>
<a name="line-193"></a><a name="protectResult"></a><span class='hs-definition'>protectResult</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>Result</span>
<a name="line-194"></a><span class='hs-definition'>protectResult</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>protect</span> <span class='hs-layout'>(</span><span class='hs-varid'>exception</span> <span class='hs-str'>"Exception"</span><span class='hs-layout'>)</span>
<a name="line-195"></a>
<a name="line-196"></a><a name="succeeded"></a><span class='hs-definition'>succeeded</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Result</span>
<a name="line-197"></a><span class='hs-definition'>succeeded</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>result</span><span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-layout'>}</span>
<a name="line-198"></a>
<a name="line-199"></a><a name="failed"></a><span class='hs-definition'>failed</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Result</span>
<a name="line-200"></a><span class='hs-definition'>failed</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>result</span><span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span> <span class='hs-layout'>}</span>
<a name="line-201"></a>
<a name="line-202"></a><a name="rejected"></a><span class='hs-definition'>rejected</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Result</span>
<a name="line-203"></a><span class='hs-definition'>rejected</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>result</span><span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span> <span class='hs-layout'>}</span>
<a name="line-204"></a>
<a name="line-205"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-206"></a><span class='hs-comment'>-- ** Lifting and mapping functions</span>
<a name="line-207"></a>
<a name="line-208"></a><a name="liftBool"></a><span class='hs-definition'>liftBool</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span>
<a name="line-209"></a><span class='hs-definition'>liftBool</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>succeeded</span>
<a name="line-210"></a><span class='hs-definition'>liftBool</span> <span class='hs-conid'>False</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>failed</span> <span class='hs-layout'>{</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Falsifiable"</span> <span class='hs-layout'>}</span>
<a name="line-211"></a>
<a name="line-212"></a><a name="mapResult"></a><span class='hs-definition'>mapResult</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-213"></a><span class='hs-definition'>mapResult</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapRoseResult</span> <span class='hs-layout'>(</span><span class='hs-varid'>protectResults</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span>
<a name="line-214"></a>
<a name="line-215"></a><a name="mapTotalResult"></a><span class='hs-definition'>mapTotalResult</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-216"></a><span class='hs-definition'>mapTotalResult</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapRoseResult</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span>
<a name="line-217"></a>
<a name="line-218"></a><a name="mapRoseResult"></a><span class='hs-comment'>-- f here mustn't throw an exception (rose tree invariant).</span>
<a name="line-219"></a><span class='hs-definition'>mapRoseResult</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-220"></a><span class='hs-definition'>mapRoseResult</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapProp</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>MkProp</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>t</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-221"></a>
<a name="line-222"></a><a name="mapProp"></a><span class='hs-definition'>mapProp</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-223"></a><span class='hs-definition'>mapProp</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-varop'>.</span> <span class='hs-varid'>property</span>
<a name="line-224"></a>
<a name="line-225"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-226"></a><span class='hs-comment'>-- ** Property combinators</span>
<a name="line-227"></a>
<a name="line-228"></a><a name="mapSize"></a><span class='hs-comment'>-- | Changes the maximum test case size for a property.</span>
<a name="line-229"></a><span class='hs-definition'>mapSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-230"></a><span class='hs-definition'>mapSize</span> <span class='hs-varid'>f</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sized</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varop'>`resize`</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span>
<a name="line-231"></a>
<a name="line-232"></a><a name="shrinking"></a><span class='hs-comment'>-- | Shrinks the argument to property if it fails. Shrinking is done</span>
<a name="line-233"></a><span class='hs-comment'>-- automatically for most types. This is only needed when you want to</span>
<a name="line-234"></a><span class='hs-comment'>-- override the default behavior.</span>
<a name="line-235"></a><span class='hs-definition'>shrinking</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span>
<a name="line-236"></a> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ 'shrink'-like function.</span>
<a name="line-237"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-comment'>-- ^ The original argument</span>
<a name="line-238"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-239"></a><span class='hs-definition'>shrinking</span> <span class='hs-varid'>shrinker</span> <span class='hs-varid'>x0</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>joinRose</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>unProp</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>promote</span> <span class='hs-layout'>(</span><span class='hs-varid'>props</span> <span class='hs-varid'>x0</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-240"></a> <span class='hs-keyword'>where</span>
<a name="line-241"></a> <span class='hs-varid'>props</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span>
<a name="line-242"></a> <span class='hs-conid'>MkRose</span> <span class='hs-layout'>(</span><span class='hs-varid'>property</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>props</span> <span class='hs-varid'>x'</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>x'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>shrinker</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>]</span>
<a name="line-243"></a>
<a name="line-244"></a><a name="noShrinking"></a><span class='hs-comment'>-- | Disables shrinking for a property altogether.</span>
<a name="line-245"></a><span class='hs-definition'>noShrinking</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-246"></a><span class='hs-definition'>noShrinking</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapRoseResult</span> <span class='hs-layout'>(</span><span class='hs-varid'>onRose</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>res</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>res</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-247"></a>
<a name="line-248"></a><a name="callback"></a><span class='hs-comment'>-- | Adds a callback</span>
<a name="line-249"></a><span class='hs-definition'>callback</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Callback</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-250"></a><span class='hs-definition'>callback</span> <span class='hs-varid'>cb</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapTotalResult</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>res</span><span class='hs-layout'>{</span> <span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cb</span> <span class='hs-conop'>:</span> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>res</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-251"></a>
<a name="line-252"></a><a name="printTestCase"></a><span class='hs-comment'>-- | Prints a message to the terminal as part of the counterexample.</span>
<a name="line-253"></a><span class='hs-definition'>printTestCase</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-254"></a><span class='hs-definition'>printTestCase</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span>
<a name="line-255"></a> <span class='hs-varid'>callback</span> <span class='hs-varop'>$</span> <span class='hs-conid'>PostFinalFailure</span> <span class='hs-conid'>Counterexample</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>st</span> <span class='hs-sel'>_res</span> <span class='hs-keyglyph'>-></span>
<a name="line-256"></a> <span class='hs-varid'>putLine</span> <span class='hs-layout'>(</span><span class='hs-varid'>terminal</span> <span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>
<a name="line-257"></a>
<a name="line-258"></a><a name="whenFail"></a><span class='hs-comment'>-- | Performs an 'IO' action after the last failure of a property.</span>
<a name="line-259"></a><span class='hs-definition'>whenFail</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-260"></a><span class='hs-definition'>whenFail</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span>
<a name="line-261"></a> <span class='hs-varid'>callback</span> <span class='hs-varop'>$</span> <span class='hs-conid'>PostFinalFailure</span> <span class='hs-conid'>NotCounterexample</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-sel'>_st</span> <span class='hs-sel'>_res</span> <span class='hs-keyglyph'>-></span>
<a name="line-262"></a> <span class='hs-varid'>m</span>
<a name="line-263"></a>
<a name="line-264"></a><a name="whenFail'"></a><span class='hs-comment'>-- | Performs an 'IO' action every time a property fails. Thus,</span>
<a name="line-265"></a><span class='hs-comment'>-- if shrinking is done, this can be used to keep track of the </span>
<a name="line-266"></a><span class='hs-comment'>-- failures along the way.</span>
<a name="line-267"></a><span class='hs-definition'>whenFail'</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-268"></a><span class='hs-definition'>whenFail'</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span>
<a name="line-269"></a> <span class='hs-varid'>callback</span> <span class='hs-varop'>$</span> <span class='hs-conid'>PostTest</span> <span class='hs-conid'>NotCounterexample</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-sel'>_st</span> <span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span>
<a name="line-270"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>res</span> <span class='hs-varop'>==</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span>
<a name="line-271"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>m</span>
<a name="line-272"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-273"></a>
<a name="line-274"></a><a name="verbose"></a><span class='hs-comment'>-- | Prints out the generated testcase every time the property is tested,</span>
<a name="line-275"></a><span class='hs-comment'>-- like 'verboseCheck' from QuickCheck 1.</span>
<a name="line-276"></a><span class='hs-comment'>-- Only variables quantified over /inside/ the 'verbose' are printed.</span>
<a name="line-277"></a><span class='hs-definition'>verbose</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-278"></a><span class='hs-definition'>verbose</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapResult</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>res</span> <span class='hs-layout'>{</span> <span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>newCallbacks</span> <span class='hs-layout'>(</span><span class='hs-varid'>callbacks</span> <span class='hs-varid'>res</span><span class='hs-layout'>)</span> <span class='hs-varop'>++</span> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>res</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-279"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>newCallbacks</span> <span class='hs-varid'>cbs</span> <span class='hs-keyglyph'>=</span>
<a name="line-280"></a> <span class='hs-conid'>PostTest</span> <span class='hs-conid'>Counterexample</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>st</span> <span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>putLine</span> <span class='hs-layout'>(</span><span class='hs-varid'>terminal</span> <span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>status</span> <span class='hs-varid'>res</span> <span class='hs-varop'>++</span> <span class='hs-str'>":"</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span>
<a name="line-281"></a> <span class='hs-keyglyph'>[</span> <span class='hs-conid'>PostTest</span> <span class='hs-conid'>Counterexample</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>PostFinalFailure</span> <span class='hs-conid'>Counterexample</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>cbs</span> <span class='hs-keyglyph'>]</span>
<a name="line-282"></a> <span class='hs-varid'>status</span> <span class='hs-conid'>MkResult</span><span class='hs-layout'>{</span><span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Passed"</span>
<a name="line-283"></a> <span class='hs-varid'>status</span> <span class='hs-conid'>MkResult</span><span class='hs-layout'>{</span><span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Failed"</span>
<a name="line-284"></a> <span class='hs-varid'>status</span> <span class='hs-conid'>MkResult</span><span class='hs-layout'>{</span><span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Skipped (precondition false)"</span>
<a name="line-285"></a>
<a name="line-286"></a><a name="expectFailure"></a><span class='hs-comment'>-- | Modifies a property so that it is expected to fail for some test cases.</span>
<a name="line-287"></a><span class='hs-definition'>expectFailure</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-288"></a><span class='hs-definition'>expectFailure</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapTotalResult</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>res</span><span class='hs-layout'>{</span> <span class='hs-varid'>expect</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-289"></a>
<a name="line-290"></a><a name="label"></a><span class='hs-comment'>-- | Attaches a label to a property. This is used for reporting</span>
<a name="line-291"></a><span class='hs-comment'>-- test case distribution.</span>
<a name="line-292"></a><span class='hs-definition'>label</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-293"></a><span class='hs-definition'>label</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>classify</span> <span class='hs-conid'>True</span> <span class='hs-varid'>s</span>
<a name="line-294"></a>
<a name="line-295"></a><a name="collect"></a><span class='hs-comment'>-- | Labels a property with a value:</span>
<a name="line-296"></a><span class='hs-comment'>--</span>
<a name="line-297"></a><span class='hs-comment'>-- > collect x = label (show x)</span>
<a name="line-298"></a><span class='hs-definition'>collect</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-299"></a><span class='hs-definition'>collect</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>label</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-300"></a>
<a name="line-301"></a><a name="classify"></a><span class='hs-comment'>-- | Conditionally labels test case.</span>
<a name="line-302"></a><span class='hs-definition'>classify</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span>
<a name="line-303"></a> <span class='hs-conid'>Bool</span> <span class='hs-comment'>-- ^ @True@ if the test case should be labelled.</span>
<a name="line-304"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ Label.</span>
<a name="line-305"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-306"></a><span class='hs-definition'>classify</span> <span class='hs-varid'>b</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cover</span> <span class='hs-varid'>b</span> <span class='hs-num'>0</span> <span class='hs-varid'>s</span>
<a name="line-307"></a>
<a name="line-308"></a><a name="cover"></a><span class='hs-comment'>-- | Checks that at least the given proportion of the test cases belong</span>
<a name="line-309"></a><span class='hs-comment'>-- to the given class.</span>
<a name="line-310"></a><span class='hs-definition'>cover</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span>
<a name="line-311"></a> <span class='hs-conid'>Bool</span> <span class='hs-comment'>-- ^ @True@ if the test case belongs to the class.</span>
<a name="line-312"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ The required percentage (0-100) of test cases.</span>
<a name="line-313"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ Label for the test case class.</span>
<a name="line-314"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-315"></a><span class='hs-definition'>cover</span> <span class='hs-conid'>True</span> <span class='hs-varid'>n</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapTotalResult</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>res</span> <span class='hs-layout'>{</span> <span class='hs-varid'>stamp</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span><span class='hs-layout'>,</span><span class='hs-varid'>n</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>stamp</span> <span class='hs-varid'>res</span> <span class='hs-layout'>}</span>
<a name="line-316"></a><span class='hs-definition'>cover</span> <span class='hs-conid'>False</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>property</span>
<a name="line-317"></a>
<a name="line-318"></a><a name="==>"></a><span class='hs-comment'>-- | Implication for properties: The resulting property holds if</span>
<a name="line-319"></a><span class='hs-comment'>-- the first argument is 'False', or if the given property holds.</span>
<a name="line-320"></a><span class='hs-layout'>(</span><span class='hs-varop'>==></span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-321"></a><span class='hs-conid'>False</span> <span class='hs-varop'>==></span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>property</span> <span class='hs-conid'>()</span>
<a name="line-322"></a><span class='hs-conid'>True</span> <span class='hs-varop'>==></span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p</span>
<a name="line-323"></a>
<a name="line-324"></a><a name="within"></a><span class='hs-comment'>-- | Considers a property failed if it does not complete within</span>
<a name="line-325"></a><span class='hs-comment'>-- the given number of microseconds.</span>
<a name="line-326"></a><span class='hs-definition'>within</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-327"></a><span class='hs-definition'>within</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapRoseResult</span> <span class='hs-varid'>f</span>
<a name="line-328"></a> <span class='hs-comment'>-- We rely on the fact that the property will catch the timeout</span>
<a name="line-329"></a> <span class='hs-comment'>-- exception and turn it into a failed test case.</span>
<a name="line-330"></a> <span class='hs-keyword'>where</span>
<a name="line-331"></a> <span class='hs-varid'>f</span> <span class='hs-varid'>rose</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ioRose</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-332"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>m</span> <span class='hs-varop'>`orError`</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromMaybe</span> <span class='hs-layout'>(</span><span class='hs-varid'>error</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>m</span>
<a name="line-333"></a> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>res</span> <span class='hs-varid'>roses</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>timeout</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>reduceRose</span> <span class='hs-varid'>rose</span><span class='hs-layout'>)</span> <span class='hs-varop'>`orError`</span>
<a name="line-334"></a> <span class='hs-str'>"within: timeout exception not caught in Rose Result"</span>
<a name="line-335"></a> <span class='hs-varid'>res'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>timeout</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>protectResult</span> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-varid'>res</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varop'>`orError`</span>
<a name="line-336"></a> <span class='hs-str'>"within: timeout exception not caught in Result"</span>
<a name="line-337"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>res'</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-varid'>f</span> <span class='hs-varid'>roses</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-338"></a>
<a name="line-339"></a><a name="forAll"></a><span class='hs-comment'>-- | Explicit universal quantification: uses an explicitly given</span>
<a name="line-340"></a><span class='hs-comment'>-- test case generator.</span>
<a name="line-341"></a><span class='hs-definition'>forAll</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span>
<a name="line-342"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Gen</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-343"></a><span class='hs-definition'>forAll</span> <span class='hs-varid'>gen</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>=</span>
<a name="line-344"></a> <span class='hs-varid'>gen</span> <span class='hs-varop'>>>=</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span>
<a name="line-345"></a> <span class='hs-varid'>printTestCase</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-346"></a>
<a name="line-347"></a><a name="forAllShrink"></a><span class='hs-comment'>-- | Like 'forAll', but tries to shrink the argument for failing test cases.</span>
<a name="line-348"></a><span class='hs-definition'>forAllShrink</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span>
<a name="line-349"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Gen</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-350"></a><span class='hs-definition'>forAllShrink</span> <span class='hs-varid'>gen</span> <span class='hs-varid'>shrinker</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>=</span>
<a name="line-351"></a> <span class='hs-varid'>gen</span> <span class='hs-varop'>>>=</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span>
<a name="line-352"></a> <span class='hs-varid'>shrinking</span> <span class='hs-varid'>shrinker</span> <span class='hs-varid'>x</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>x'</span> <span class='hs-keyglyph'>-></span>
<a name="line-353"></a> <span class='hs-varid'>printTestCase</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>x'</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varid'>x'</span><span class='hs-layout'>)</span>
<a name="line-354"></a>
<a name="line-355"></a><a name=".&."></a><span class='hs-comment'>-- | Nondeterministic choice: 'p1' '.&.' 'p2' picks randomly one of</span>
<a name="line-356"></a><span class='hs-comment'>-- 'p1' and 'p2' to test. If you test the property 100 times it</span>
<a name="line-357"></a><span class='hs-comment'>-- makes 100 random choices.</span>
<a name="line-358"></a><span class='hs-layout'>(</span><span class='hs-varop'>.&.</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Testable</span> <span class='hs-varid'>prop1</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop1</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop2</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-359"></a><a name="p1"></a><span class='hs-definition'>p1</span> <span class='hs-varop'>.&.</span> <span class='hs-varid'>p2</span> <span class='hs-keyglyph'>=</span>
<a name="line-360"></a> <span class='hs-varid'>arbitrary</span> <span class='hs-varop'>>>=</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span>
<a name="line-361"></a> <span class='hs-varid'>printTestCase</span> <span class='hs-layout'>(</span><span class='hs-keyword'>if</span> <span class='hs-varid'>b</span> <span class='hs-keyword'>then</span> <span class='hs-str'>"LHS"</span> <span class='hs-keyword'>else</span> <span class='hs-str'>"RHS"</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span>
<a name="line-362"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>b</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p1</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p2</span>
<a name="line-363"></a>
<a name="line-364"></a><a name=".&&."></a><span class='hs-comment'>-- | Conjunction: 'p1' '.&&.' 'p2' passes if both 'p1' and 'p2' pass.</span>
<a name="line-365"></a><span class='hs-layout'>(</span><span class='hs-varop'>.&&.</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Testable</span> <span class='hs-varid'>prop1</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop1</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop2</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-366"></a><span class='hs-definition'>p1</span> <span class='hs-varop'>.&&.</span> <span class='hs-varid'>p2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>conjoin</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>property</span> <span class='hs-varid'>p1</span><span class='hs-layout'>,</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p2</span><span class='hs-keyglyph'>]</span>
<a name="line-367"></a>
<a name="line-368"></a><a name="conjoin"></a><span class='hs-comment'>-- | Take the conjunction of several properties.</span>
<a name="line-369"></a><span class='hs-definition'>conjoin</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>prop</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-370"></a><span class='hs-definition'>conjoin</span> <span class='hs-varid'>ps</span> <span class='hs-keyglyph'>=</span>
<a name="line-371"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>roses</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mapM</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>unProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>property</span><span class='hs-layout'>)</span> <span class='hs-varid'>ps</span>
<a name="line-372"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-layout'>(</span><span class='hs-varid'>conj</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>roses</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-373"></a> <span class='hs-keyword'>where</span>
<a name="line-374"></a> <span class='hs-varid'>conj</span> <span class='hs-varid'>cbs</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span>
<a name="line-375"></a> <span class='hs-conid'>MkRose</span> <span class='hs-varid'>succeeded</span><span class='hs-layout'>{</span><span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cbs</span><span class='hs-layout'>}</span> <span class='hs-conid'>[]</span>
<a name="line-376"></a>
<a name="line-377"></a> <span class='hs-varid'>conj</span> <span class='hs-varid'>cbs</span> <span class='hs-layout'>(</span><span class='hs-varid'>p</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ps</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IORose</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-378"></a> <span class='hs-varid'>rose</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>result</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>reduceRose</span> <span class='hs-varid'>p</span>
<a name="line-379"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>result</span> <span class='hs-keyword'>of</span>
<a name="line-380"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>expect</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-381"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-varid'>failed</span> <span class='hs-layout'>{</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"expectFailure may not occur inside a conjunction"</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-382"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>conj</span> <span class='hs-layout'>(</span><span class='hs-varid'>cbs</span> <span class='hs-varop'>++</span> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-varid'>ps</span><span class='hs-layout'>)</span>
<a name="line-383"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>rose</span>
<a name="line-384"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-385"></a> <span class='hs-varid'>rose2</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>result2</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>reduceRose</span> <span class='hs-layout'>(</span><span class='hs-varid'>conj</span> <span class='hs-layout'>(</span><span class='hs-varid'>cbs</span> <span class='hs-varop'>++</span> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-varid'>ps</span><span class='hs-layout'>)</span>
<a name="line-386"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span>
<a name="line-387"></a> <span class='hs-comment'>-- Nasty work to make sure we use the right callbacks</span>
<a name="line-388"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>result2</span> <span class='hs-keyword'>of</span>
<a name="line-389"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>MkRose</span> <span class='hs-layout'>(</span><span class='hs-varid'>result2</span> <span class='hs-layout'>{</span> <span class='hs-varid'>ok</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-390"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>rose2</span>
<a name="line-391"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>rose2</span>
<a name="line-392"></a>
<a name="line-393"></a><a name=".||."></a><span class='hs-comment'>-- | Disjunction: 'p1' '.||.' 'p2' passes unless 'p1' and 'p2' simultaneously fail.</span>
<a name="line-394"></a><span class='hs-layout'>(</span><span class='hs-varop'>.||.</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Testable</span> <span class='hs-varid'>prop1</span><span class='hs-layout'>,</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>prop1</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>prop2</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-395"></a><span class='hs-definition'>p1</span> <span class='hs-varop'>.||.</span> <span class='hs-varid'>p2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>disjoin</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>property</span> <span class='hs-varid'>p1</span><span class='hs-layout'>,</span> <span class='hs-varid'>property</span> <span class='hs-varid'>p2</span><span class='hs-keyglyph'>]</span>
<a name="line-396"></a>
<a name="line-397"></a><a name="disjoin"></a><span class='hs-comment'>-- | Take the disjunction of several properties.</span>
<a name="line-398"></a><span class='hs-definition'>disjoin</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Testable</span> <span class='hs-varid'>prop</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>prop</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span>
<a name="line-399"></a><span class='hs-definition'>disjoin</span> <span class='hs-varid'>ps</span> <span class='hs-keyglyph'>=</span>
<a name="line-400"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>roses</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mapM</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>unProp</span> <span class='hs-varop'>.</span> <span class='hs-varid'>property</span><span class='hs-layout'>)</span> <span class='hs-varid'>ps</span>
<a name="line-401"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkProp</span> <span class='hs-layout'>(</span><span class='hs-varid'>foldr</span> <span class='hs-varid'>disj</span> <span class='hs-layout'>(</span><span class='hs-conid'>MkRose</span> <span class='hs-varid'>failed</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-varid'>roses</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-402"></a> <span class='hs-keyword'>where</span>
<a name="line-403"></a> <span class='hs-varid'>disj</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Rose</span> <span class='hs-conid'>Result</span>
<a name="line-404"></a> <span class='hs-varid'>disj</span> <span class='hs-varid'>p</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=</span>
<a name="line-405"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>result1</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>p</span>
<a name="line-406"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>result1</span> <span class='hs-keyword'>of</span>
<a name="line-407"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>expect</span> <span class='hs-varid'>result1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>expectFailureError</span>
<a name="line-408"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>result1</span>
<a name="line-409"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-410"></a> <span class='hs-varid'>result2</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>q</span>
<a name="line-411"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span>
<a name="line-412"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>expect</span> <span class='hs-varid'>result2</span> <span class='hs-keyword'>then</span>
<a name="line-413"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>result2</span> <span class='hs-keyword'>of</span>
<a name="line-414"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>result2</span>
<a name="line-415"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>False</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>result1</span> <span class='hs-varop'>>>></span> <span class='hs-varid'>result2</span>
<a name="line-416"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>result2</span>
<a name="line-417"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>expectFailureError</span>
<a name="line-418"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-419"></a> <span class='hs-varid'>result2</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>q</span>
<a name="line-420"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-keyword'>case</span> <span class='hs-varid'>ok</span> <span class='hs-varid'>result2</span> <span class='hs-keyword'>of</span>
<a name="line-421"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>expect</span> <span class='hs-varid'>result2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>expectFailureError</span>
<a name="line-422"></a> <span class='hs-conid'>Just</span> <span class='hs-conid'>True</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>result2</span>
<a name="line-423"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>result1</span><span class='hs-layout'>)</span>
<a name="line-424"></a>
<a name="line-425"></a> <span class='hs-varid'>expectFailureError</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>failed</span> <span class='hs-layout'>{</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"expectFailure may not occur inside a disjunction"</span> <span class='hs-layout'>}</span>
<a name="line-426"></a> <span class='hs-varid'>result1</span> <span class='hs-varop'>>>></span> <span class='hs-varid'>result2</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>expect</span> <span class='hs-varid'>result1</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>expect</span> <span class='hs-varid'>result2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>expectFailureError</span>
<a name="line-427"></a> <span class='hs-varid'>result1</span> <span class='hs-varop'>>>></span> <span class='hs-varid'>result2</span> <span class='hs-keyglyph'>=</span>
<a name="line-428"></a> <span class='hs-varid'>result2</span>
<a name="line-429"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>reason</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>null</span> <span class='hs-layout'>(</span><span class='hs-varid'>reason</span> <span class='hs-varid'>result2</span><span class='hs-layout'>)</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>reason</span> <span class='hs-varid'>result1</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>reason</span> <span class='hs-varid'>result2</span>
<a name="line-430"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>interrupted</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>interrupted</span> <span class='hs-varid'>result1</span> <span class='hs-varop'>||</span> <span class='hs-varid'>interrupted</span> <span class='hs-varid'>result2</span>
<a name="line-431"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>stamp</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>stamp</span> <span class='hs-varid'>result1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>stamp</span> <span class='hs-varid'>result2</span>
<a name="line-432"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>callbacks</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>result1</span> <span class='hs-varop'>++</span>
<a name="line-433"></a> <span class='hs-keyglyph'>[</span><span class='hs-conid'>PostFinalFailure</span> <span class='hs-conid'>Counterexample</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>st</span> <span class='hs-sel'>_res</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>putLine</span> <span class='hs-layout'>(</span><span class='hs-varid'>terminal</span> <span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-str'>""</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>++</span>
<a name="line-434"></a> <span class='hs-varid'>callbacks</span> <span class='hs-varid'>result2</span>
<a name="line-435"></a> <span class='hs-layout'>}</span>
<a name="line-436"></a>
<a name="line-437"></a><span class='hs-comment'>--------------------------------------------------------------------------</span>
<a name="line-438"></a><span class='hs-comment'>-- the end.</span>
</pre></body>
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