<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ -->
<title>src/Text/ParserCombinators/Parsec/Utils.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{- arch-tag: Parsec utilities
<a name="line-2"></a>Copyright (C) 2004 John Goerzen <jgoerzen@complete.org>
<a name="line-3"></a>
<a name="line-4"></a>This program is free software; you can redistribute it and/or modify
<a name="line-5"></a>it under the terms of the GNU General Public License as published by
<a name="line-6"></a>the Free Software Foundation; either version 2 of the License, or
<a name="line-7"></a>(at your option) any later version.
<a name="line-8"></a>
<a name="line-9"></a>This program is distributed in the hope that it will be useful,
<a name="line-10"></a>but WITHOUT ANY WARRANTY; without even the implied warranty of
<a name="line-11"></a>MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
<a name="line-12"></a>GNU General Public License for more details.
<a name="line-13"></a>
<a name="line-14"></a>You should have received a copy of the GNU General Public License
<a name="line-15"></a>along with this program; if not, write to the Free Software
<a name="line-16"></a>Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
<a name="line-17"></a>-}</span>
<a name="line-18"></a>
<a name="line-19"></a><span class='hs-comment'>{- |
<a name="line-20"></a> Module : Text.ParserCombinators.Parsec.Utils
<a name="line-21"></a> Copyright : Copyright (C) 2004 John Goerzen
<a name="line-22"></a> License : GNU GPL, version 2 or above
<a name="line-23"></a>
<a name="line-24"></a> Maintainer : John Goerzen <jgoerzen@complete.org>
<a name="line-25"></a> Stability : provisional
<a name="line-26"></a> Portability: portable
<a name="line-27"></a>
<a name="line-28"></a>Written by John Goerzen, jgoerzen\@complete.org
<a name="line-29"></a>
<a name="line-30"></a>-}</span>
<a name="line-31"></a>
<a name="line-32"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>ParserCombinators</span><span class='hs-varop'>.</span><span class='hs-conid'>Parsec</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span><span class='hs-layout'>(</span><span class='hs-comment'>-- * Generalized Utilities</span>
<a name="line-33"></a> <span class='hs-comment'>-- | These functions are generalized versions of</span>
<a name="line-34"></a> <span class='hs-comment'>-- ones you might see in the Char parser.</span>
<a name="line-35"></a> <span class='hs-conid'>GeneralizedToken</span><span class='hs-layout'>,</span> <span class='hs-conid'>GeneralizedTokenParser</span><span class='hs-layout'>,</span>
<a name="line-36"></a> <span class='hs-varid'>togtok</span><span class='hs-layout'>,</span> <span class='hs-varid'>tokeng</span><span class='hs-layout'>,</span> <span class='hs-varid'>satisfyg</span><span class='hs-layout'>,</span> <span class='hs-varid'>oneOfg</span><span class='hs-layout'>,</span> <span class='hs-varid'>noneOfg</span><span class='hs-layout'>,</span>
<a name="line-37"></a> <span class='hs-varid'>specificg</span><span class='hs-layout'>,</span> <span class='hs-varid'>allg</span><span class='hs-layout'>,</span>
<a name="line-38"></a> <span class='hs-comment'>-- * Other Utilities</span>
<a name="line-39"></a> <span class='hs-varid'>notMatching</span>
<a name="line-40"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-41"></a>
<a name="line-42"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>ParserCombinators</span><span class='hs-varop'>.</span><span class='hs-conid'>Parsec</span>
<a name="line-43"></a>
<a name="line-44"></a><a name="GeneralizedToken"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>GeneralizedToken</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>SourcePos</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-45"></a><a name="GeneralizedTokenParser"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>GenParser</span> <span class='hs-layout'>(</span><span class='hs-conid'>GeneralizedToken</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-varid'>st</span> <span class='hs-varid'>b</span>
<a name="line-46"></a>
<a name="line-47"></a><a name="togtok"></a><span class='hs-comment'>{- | Generate (return) a 'GeneralizedToken'. -}</span>
<a name="line-48"></a><span class='hs-definition'>togtok</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GenParser</span> <span class='hs-varid'>b</span> <span class='hs-varid'>st</span> <span class='hs-layout'>(</span><span class='hs-conid'>GeneralizedToken</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-49"></a><span class='hs-definition'>togtok</span> <span class='hs-varid'>tok</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-50"></a> <span class='hs-varid'>x</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getPosition</span>
<a name="line-51"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-layout'>,</span> <span class='hs-varid'>tok</span><span class='hs-layout'>)</span>
<a name="line-52"></a>
<a name="line-53"></a><a name="tokeng"></a><span class='hs-comment'>{- | Retrieve the next token from a 'GeneralizedToken' stream.
<a name="line-54"></a> The given function should return the value to use, or Nothing
<a name="line-55"></a> to cause an error. -}</span>
<a name="line-56"></a><span class='hs-definition'>tokeng</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-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>b</span>
<a name="line-57"></a><span class='hs-definition'>tokeng</span> <span class='hs-varid'>test</span> <span class='hs-keyglyph'>=</span>
<a name="line-58"></a> <span class='hs-varid'>token</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varop'>.</span> <span class='hs-varid'>snd</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fst</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>test</span> <span class='hs-varop'>.</span> <span class='hs-varid'>snd</span><span class='hs-layout'>)</span>
<a name="line-59"></a>
<a name="line-60"></a><a name="satisfyg"></a><span class='hs-comment'>{- | A shortcut to 'tokeng'; the test here is just a function that returns
<a name="line-61"></a>a Bool. If the result is true; return that value -- otherwise, an error.
<a name="line-62"></a>-}</span>
<a name="line-63"></a><span class='hs-definition'>satisfyg</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-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>a</span>
<a name="line-64"></a><span class='hs-definition'>satisfyg</span> <span class='hs-varid'>test</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>tokeng</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>t</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>if</span> <span class='hs-varid'>test</span> <span class='hs-varid'>t</span> <span class='hs-keyword'>then</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>t</span> <span class='hs-keyword'>else</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span>
<a name="line-65"></a>
<a name="line-66"></a><a name="oneOfg"></a><span class='hs-comment'>{- | Matches one item in a list and returns it. -}</span>
<a name="line-67"></a><span class='hs-definition'>oneOfg</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</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-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>a</span>
<a name="line-68"></a><span class='hs-definition'>oneOfg</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>satisfyg</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>elem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span>
<a name="line-69"></a>
<a name="line-70"></a><a name="allg"></a><span class='hs-comment'>{- | Matches all items and returns them -}</span>
<a name="line-71"></a><span class='hs-definition'>allg</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-keyglyph'>=></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-72"></a><span class='hs-definition'>allg</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>many</span> <span class='hs-varop'>$</span> <span class='hs-varid'>satisfyg</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>True</span><span class='hs-layout'>)</span>
<a name="line-73"></a>
<a name="line-74"></a><a name="noneOfg"></a><span class='hs-comment'>{- | Matches one item not in a list and returns it. -}</span>
<a name="line-75"></a><span class='hs-definition'>noneOfg</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</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-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>a</span>
<a name="line-76"></a><span class='hs-definition'>noneOfg</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>satisfyg</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>elem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-77"></a>
<a name="line-78"></a><a name="specificg"></a><span class='hs-comment'>{- | Matches one specific token and returns it. -}</span>
<a name="line-79"></a><span class='hs-definition'>specificg</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</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-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GeneralizedTokenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>st</span> <span class='hs-varid'>a</span>
<a name="line-80"></a><span class='hs-definition'>specificg</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>satisfyg</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-varop'><?></span> <span class='hs-varid'>show</span> <span class='hs-varid'>i</span>
<a name="line-81"></a>
<a name="line-82"></a><span class='hs-comment'>{- Matches a list of tokens and returns it. -}</span>
<a name="line-83"></a><span class='hs-comment'>{-
<a name="line-84"></a>listg :: (Eq a, Show a) => [GeneralizedToken a] -> GeneralizedTokenParser a st [GeneralizedToken a]
<a name="line-85"></a>listg l = tokens (show . map fst) nextpos l
<a name="line-86"></a> where
<a name="line-87"></a> tokpos = fst
<a name="line-88"></a> nextpos
<a name="line-89"></a> nextposs _ _ (tok:toks) = tokpos tok
<a name="line-90"></a> nextposs _ tok [] = tokpos tok
<a name="line-91"></a> nextpos pos x = nextposs pos [x]
<a name="line-92"></a>-}</span>
<a name="line-93"></a>
<a name="line-94"></a><a name="notMatching"></a><span class='hs-comment'>{- | Running @notMatching p msg@ will try to apply parser p.
<a name="line-95"></a>If it fails, returns (). If it succeds, cause a failure and raise
<a name="line-96"></a>the given error message. It will not consume input in either case. -}</span>
<a name="line-97"></a><span class='hs-definition'>notMatching</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GenParser</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-conid'>()</span>
<a name="line-98"></a><span class='hs-definition'>notMatching</span> <span class='hs-varid'>p</span> <span class='hs-varid'>errormsg</span> <span class='hs-keyglyph'>=</span>
<a name="line-99"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>maybeRead</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>try</span> <span class='hs-layout'>(</span><span class='hs-keyword'>do</span>
<a name="line-100"></a> <span class='hs-varid'>x</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>p</span>
<a name="line-101"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-102"></a> <span class='hs-layout'>)</span>
<a name="line-103"></a> <span class='hs-varop'><|></span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-104"></a> <span class='hs-varid'>workerFunc</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-105"></a> <span class='hs-varid'>x</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>maybeRead</span>
<a name="line-106"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>x</span> <span class='hs-keyword'>of</span>
<a name="line-107"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-108"></a> <span class='hs-conid'>Just</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>unexpected</span> <span class='hs-varid'>errormsg</span>
<a name="line-109"></a> <span class='hs-keyword'>in</span>
<a name="line-110"></a> <span class='hs-varid'>try</span> <span class='hs-varid'>workerFunc</span>
<a name="line-111"></a>
</pre></body>
</html>
