<?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>Text/StringLike.hs</title> <link type='text/css' rel='stylesheet' href='hscolour.css' /> </head> <body> <pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE TypeSynonymInstances #-}</span> <a name="line-2"></a> <a name="line-3"></a><span class='hs-comment'>-- | /WARNING/: This module is /not/ intended for use outside the TagSoup library.</span> <a name="line-4"></a><span class='hs-comment'>--</span> <a name="line-5"></a><span class='hs-comment'>-- This module provides an abstraction for String's as used inside TagSoup. It allows</span> <a name="line-6"></a><span class='hs-comment'>-- TagSoup to work with String (list of Char), ByteString.Char8 and ByteString.Lazy.Char8.</span> <a name="line-7"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>StringLike</span> <span class='hs-keyword'>where</span> <a name="line-8"></a> <a name="line-9"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Typeable</span> <a name="line-10"></a> <a name="line-11"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Char8</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>BS</span> <a name="line-12"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span><span class='hs-varop'>.</span><span class='hs-conid'>Char8</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>LBS</span> <a name="line-13"></a> <a name="line-14"></a> <a name="line-15"></a><a name="StringLike"></a><span class='hs-comment'>-- | A class to generalise TagSoup parsing over many types of string-like types.</span> <a name="line-16"></a><a name="StringLike"></a><span class='hs-comment'>-- Examples are given for the String type.</span> <a name="line-17"></a><a name="StringLike"></a><span class='hs-keyword'>class</span> <span class='hs-layout'>(</span><span class='hs-conid'>Typeable</span> <span class='hs-varid'>a</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-keyglyph'>=></span> <span class='hs-conid'>StringLike</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>where</span> <a name="line-18"></a> <span class='hs-comment'>-- | > empty = ""</span> <a name="line-19"></a> <span class='hs-varid'>empty</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <a name="line-20"></a> <span class='hs-comment'>-- | > cons = (:)</span> <a name="line-21"></a> <span class='hs-varid'>cons</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Char</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <a name="line-22"></a> <span class='hs-comment'>-- | > uncons [] = Nothing</span> <a name="line-23"></a> <span class='hs-comment'>-- > uncons (x:xs) = Just (x, xs)</span> <a name="line-24"></a> <span class='hs-varid'>uncons</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>Char</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <a name="line-25"></a> <a name="line-26"></a> <span class='hs-comment'>-- | > toString = id</span> <a name="line-27"></a> <span class='hs-varid'>toString</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <a name="line-28"></a> <span class='hs-comment'>-- | > fromString = id</span> <a name="line-29"></a> <span class='hs-varid'>fromString</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <a name="line-30"></a> <span class='hs-comment'>-- | > fromChar = return</span> <a name="line-31"></a> <span class='hs-varid'>fromChar</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Char</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <a name="line-32"></a> <span class='hs-comment'>-- | > strConcat = concat</span> <a name="line-33"></a> <span class='hs-varid'>strConcat</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-varid'>a</span> <a name="line-34"></a> <span class='hs-comment'>-- | > strNull = null</span> <a name="line-35"></a> <span class='hs-varid'>strNull</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span> <a name="line-36"></a> <span class='hs-comment'>-- | > append = (++)</span> <a name="line-37"></a> <span class='hs-varid'>append</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <a name="line-38"></a> <a name="line-39"></a> <a name="line-40"></a><a name="castString"></a><span class='hs-comment'>-- | Convert a String from one type to another.</span> <a name="line-41"></a><span class='hs-definition'>castString</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>StringLike</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>StringLike</span> <span class='hs-varid'>b</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'>b</span> <a name="line-42"></a><span class='hs-definition'>castString</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromString</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toString</span> <a name="line-43"></a> <a name="line-44"></a> <a name="line-45"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>StringLike</span> <span class='hs-conid'>String</span> <span class='hs-keyword'>where</span> <a name="line-46"></a> <span class='hs-varid'>uncons</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span> <a name="line-47"></a> <span class='hs-varid'>uncons</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-layout'>,</span> <span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <a name="line-48"></a> <span class='hs-varid'>toString</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>id</span> <a name="line-49"></a> <span class='hs-varid'>fromString</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>id</span> <a name="line-50"></a> <span class='hs-varid'>fromChar</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conop'>:</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <a name="line-51"></a> <span class='hs-varid'>strConcat</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>concat</span> <a name="line-52"></a> <span class='hs-varid'>empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <a name="line-53"></a> <span class='hs-varid'>strNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>null</span> <a name="line-54"></a> <span class='hs-varid'>cons</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span> <a name="line-55"></a> <span class='hs-varid'>append</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varop'>++</span><span class='hs-layout'>)</span> <a name="line-56"></a> <a name="line-57"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>StringLike</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyword'>where</span> <a name="line-58"></a> <span class='hs-varid'>uncons</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>uncons</span> <a name="line-59"></a> <span class='hs-varid'>toString</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>unpack</span> <a name="line-60"></a> <span class='hs-varid'>fromString</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>pack</span> <a name="line-61"></a> <span class='hs-varid'>fromChar</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>singleton</span> <a name="line-62"></a> <span class='hs-varid'>strConcat</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>concat</span> <a name="line-63"></a> <span class='hs-varid'>empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>empty</span> <a name="line-64"></a> <span class='hs-varid'>strNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>null</span> <a name="line-65"></a> <span class='hs-varid'>cons</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>cons</span> <a name="line-66"></a> <span class='hs-varid'>append</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BS</span><span class='hs-varop'>.</span><span class='hs-varid'>append</span> <a name="line-67"></a> <a name="line-68"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>StringLike</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyword'>where</span> <a name="line-69"></a> <span class='hs-varid'>uncons</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>uncons</span> <a name="line-70"></a> <span class='hs-varid'>toString</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>unpack</span> <a name="line-71"></a> <span class='hs-varid'>fromString</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>pack</span> <a name="line-72"></a> <span class='hs-varid'>fromChar</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>singleton</span> <a name="line-73"></a> <span class='hs-varid'>strConcat</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>concat</span> <a name="line-74"></a> <span class='hs-varid'>empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>empty</span> <a name="line-75"></a> <span class='hs-varid'>strNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>null</span> <a name="line-76"></a> <span class='hs-varid'>cons</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>cons</span> <a name="line-77"></a> <span class='hs-varid'>append</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LBS</span><span class='hs-varop'>.</span><span class='hs-varid'>append</span> </pre></body> </html>