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<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 : Distribution.ReadE</span>
<a name="line-4"></a><span class='hs-comment'>-- Copyright : Jose Iborra 2008</span>
<a name="line-5"></a><span class='hs-comment'>--</span>
<a name="line-6"></a><span class='hs-comment'>-- Maintainer : cabal-devel@haskell.org</span>
<a name="line-7"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-8"></a><span class='hs-comment'>--</span>
<a name="line-9"></a><span class='hs-comment'>-- Simple parsing with failure</span>
<a name="line-10"></a>
<a name="line-11"></a><span class='hs-comment'>{- Copyright (c) 2007, Jose Iborra
<a name="line-12"></a>All rights reserved.
<a name="line-13"></a>
<a name="line-14"></a>Redistribution and use in source and binary forms, with or without
<a name="line-15"></a>modification, are permitted provided that the following conditions are
<a name="line-16"></a>met:
<a name="line-17"></a>
<a name="line-18"></a> * Redistributions of source code must retain the above copyright
<a name="line-19"></a> notice, this list of conditions and the following disclaimer.
<a name="line-20"></a>
<a name="line-21"></a> * Redistributions in binary form must reproduce the above
<a name="line-22"></a> copyright notice, this list of conditions and the following
<a name="line-23"></a> disclaimer in the documentation and/or other materials provided
<a name="line-24"></a> with the distribution.
<a name="line-25"></a>
<a name="line-26"></a> * Neither the name of Isaac Jones nor the names of other
<a name="line-27"></a> contributors may be used to endorse or promote products derived
<a name="line-28"></a> from this software without specific prior written permission.
<a name="line-29"></a>
<a name="line-30"></a>THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
<a name="line-31"></a>"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
<a name="line-32"></a>LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
<a name="line-33"></a>A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
<a name="line-34"></a>OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
<a name="line-35"></a>SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
<a name="line-36"></a>LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
<a name="line-37"></a>DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
<a name="line-38"></a>THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
<a name="line-39"></a>(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
<a name="line-40"></a>OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -}</span>
<a name="line-41"></a>
<a name="line-42"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Distribution</span><span class='hs-varop'>.</span><span class='hs-conid'>ReadE</span> <span class='hs-layout'>(</span>
<a name="line-43"></a> <span class='hs-comment'>-- * ReadE</span>
<a name="line-44"></a> <span class='hs-conid'>ReadE</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'>succeedReadE</span><span class='hs-layout'>,</span> <span class='hs-varid'>failReadE</span><span class='hs-layout'>,</span>
<a name="line-45"></a> <span class='hs-comment'>-- * Projections</span>
<a name="line-46"></a> <span class='hs-varid'>parseReadE</span><span class='hs-layout'>,</span> <span class='hs-varid'>readEOrFail</span><span class='hs-layout'>,</span>
<a name="line-47"></a> <span class='hs-varid'>readP_to_E</span>
<a name="line-48"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-49"></a>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Distribution</span><span class='hs-varop'>.</span><span class='hs-conid'>Compat</span><span class='hs-varop'>.</span><span class='hs-conid'>ReadP</span>
<a name="line-51"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Char</span> <span class='hs-layout'>(</span> <span class='hs-varid'>isSpace</span> <span class='hs-layout'>)</span>
<a name="line-52"></a>
<a name="line-53"></a><a name="ReadE"></a><span class='hs-comment'>-- | Parser with simple error reporting</span>
<a name="line-54"></a><a name="ReadE"></a><span class='hs-keyword'>newtype</span> <span class='hs-conid'>ReadE</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ReadE</span> <span class='hs-layout'>{</span><span class='hs-varid'>runReadE</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-conid'>ErrorMsg</span> <span class='hs-varid'>a</span><span class='hs-layout'>}</span>
<a name="line-55"></a><a name="ErrorMsg"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>ErrorMsg</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>String</span>
<a name="line-56"></a>
<a name="line-57"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Functor</span> <span class='hs-conid'>ReadE</span> <span class='hs-keyword'>where</span>
<a name="line-58"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>ReadE</span> <span class='hs-varid'>p</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ReadE</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>txt</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>p</span> <span class='hs-varid'>txt</span> <span class='hs-keyword'>of</span>
<a name="line-59"></a> <span class='hs-conid'>Right</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Right</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-60"></a> <span class='hs-conid'>Left</span> <span class='hs-varid'>err</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Left</span> <span class='hs-varid'>err</span>
<a name="line-61"></a>
<a name="line-62"></a><a name="succeedReadE"></a><span class='hs-definition'>succeedReadE</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>String</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'>ReadE</span> <span class='hs-varid'>a</span>
<a name="line-63"></a><span class='hs-definition'>succeedReadE</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ReadE</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span>
<a name="line-64"></a>
<a name="line-65"></a><a name="failReadE"></a><span class='hs-definition'>failReadE</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ErrorMsg</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ReadE</span> <span class='hs-varid'>a</span>
<a name="line-66"></a><span class='hs-definition'>failReadE</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ReadE</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span> <span class='hs-conid'>Left</span>
<a name="line-67"></a>
<a name="line-68"></a><a name="parseReadE"></a><span class='hs-definition'>parseReadE</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ReadE</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ReadP</span> <span class='hs-varid'>r</span> <span class='hs-varid'>a</span>
<a name="line-69"></a><span class='hs-definition'>parseReadE</span> <span class='hs-layout'>(</span><span class='hs-conid'>ReadE</span> <span class='hs-varid'>p</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-70"></a> <span class='hs-varid'>txt</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>look</span>
<a name="line-71"></a> <span class='hs-varid'>either</span> <span class='hs-varid'>fail</span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>p</span> <span class='hs-varid'>txt</span><span class='hs-layout'>)</span>
<a name="line-72"></a>
<a name="line-73"></a><a name="readEOrFail"></a><span class='hs-definition'>readEOrFail</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ReadE</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-74"></a><span class='hs-definition'>readEOrFail</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>either</span> <span class='hs-varid'>error</span> <span class='hs-varid'>id</span> <span class='hs-varop'>.</span> <span class='hs-varid'>runReadE</span> <span class='hs-varid'>r</span>
<a name="line-75"></a>
<a name="line-76"></a><a name="readP_to_E"></a><span class='hs-definition'>readP_to_E</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ErrorMsg</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ReadP</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ReadE</span> <span class='hs-varid'>a</span>
<a name="line-77"></a><span class='hs-definition'>readP_to_E</span> <span class='hs-varid'>err</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span>
<a name="line-78"></a> <span class='hs-conid'>ReadE</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>txt</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-varid'>p</span><span class='hs-layout'>,</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readP_to_S</span> <span class='hs-varid'>r</span> <span class='hs-varid'>txt</span>
<a name="line-79"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>all</span> <span class='hs-varid'>isSpace</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>]</span>
<a name="line-80"></a> <span class='hs-keyword'>of</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Left</span> <span class='hs-layout'>(</span><span class='hs-varid'>err</span> <span class='hs-varid'>txt</span><span class='hs-layout'>)</span>
<a name="line-81"></a> <span class='hs-layout'>(</span><span class='hs-varid'>p</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Right</span> <span class='hs-varid'>p</span>
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