164 lines
21 KiB
HTML
164 lines
21 KiB
HTML
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
|
<title>regex_split (deprecated)</title>
|
|
<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
|
<link rel="home" href="../../../index.html" title="Boost.Regex 5.1.4">
|
|
<link rel="up" href="../deprecated.html" title="Deprecated Interfaces">
|
|
<link rel="prev" href="regex_grep.html" title="regex_grep (Deprecated)">
|
|
<link rel="next" href="old_regex.html" title="High Level Class RegEx (Deprecated)">
|
|
</head>
|
|
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
|
<table cellpadding="2" width="100%"><tr>
|
|
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
|
|
<td align="center"><a href="../../../../../../../index.html">Home</a></td>
|
|
<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
|
|
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
|
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
|
<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
|
|
</tr></table>
|
|
<hr>
|
|
<div class="spirit-nav">
|
|
<a accesskey="p" href="regex_grep.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../deprecated.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="old_regex.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h4 class="title">
|
|
<a name="boost_regex.ref.deprecated.regex_split"></a><a class="link" href="regex_split.html" title="regex_split (deprecated)">regex_split
|
|
(deprecated)</a>
|
|
</h4></div></div></div>
|
|
<p>
|
|
The algorithm <a class="link" href="regex_split.html" title="regex_split (deprecated)"><code class="computeroutput"><span class="identifier">regex_split</span></code></a> has been deprecated
|
|
in favor of the iterator <a class="link" href="../regex_token_iterator.html" title="regex_token_iterator"><code class="computeroutput"><span class="identifier">regex_token_iterator</span></code></a> which has
|
|
a more flexible and powerful interface, as well as following the more usual
|
|
standard library "pull" rather than "push" semantics.
|
|
</p>
|
|
<p>
|
|
Code which uses <a class="link" href="regex_split.html" title="regex_split (deprecated)"><code class="computeroutput"><span class="identifier">regex_split</span></code></a> will continue to compile,
|
|
the following documentation is taken from a previous Boost.Regex version:
|
|
</p>
|
|
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
|
</pre>
|
|
<p>
|
|
Algorithm <a class="link" href="regex_split.html" title="regex_split (deprecated)"><code class="computeroutput"><span class="identifier">regex_split</span></code></a> performs a similar
|
|
operation to the perl split operation, and comes in three overloaded forms:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Alloc1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Traits2</span><span class="special">></span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">regex_split</span><span class="special">(</span><span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="identifier">Alloc1</span><span class="special">>&</span> <span class="identifier">s</span><span class="special">,</span>
|
|
<span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">Traits2</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">flags</span><span class="special">,</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_split</span><span class="special">);</span>
|
|
|
|
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Alloc1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Traits2</span><span class="special">></span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">regex_split</span><span class="special">(</span><span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="identifier">Alloc1</span><span class="special">>&</span> <span class="identifier">s</span><span class="special">,</span>
|
|
<span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">Traits2</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
|
|
|
|
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Alloc1</span><span class="special">></span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">regex_split</span><span class="special">(</span><span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">Traits1</span><span class="special">,</span> <span class="identifier">Alloc1</span><span class="special">>&</span> <span class="identifier">s</span><span class="special">);</span>
|
|
</pre>
|
|
<p>
|
|
<span class="bold"><strong>Effects</strong></span>: Each version of the algorithm
|
|
takes an output-iterator for output, and a string for input. If the expression
|
|
contains no marked sub-expressions, then the algorithm writes one string
|
|
onto the output-iterator for each section of input that does not match
|
|
the expression. If the expression does contain marked sub-expressions,
|
|
then each time a match is found, one string for each marked sub-expression
|
|
will be written to the output-iterator. No more than max_split strings
|
|
will be written to the output-iterator. Before returning, all the input
|
|
processed will be deleted from the string <span class="emphasis"><em>s</em></span> (if <span class="emphasis"><em>max_split</em></span>
|
|
is not reached then all of <span class="emphasis"><em>s</em></span> will be deleted). Returns
|
|
the number of strings written to the output-iterator. If the parameter
|
|
<span class="emphasis"><em>max_split</em></span> is not specified then it defaults to <code class="computeroutput"><span class="identifier">UINT_MAX</span></code>. If no expression is specified,
|
|
then it defaults to "\s+", and splitting occurs on whitespace.
|
|
</p>
|
|
<p>
|
|
<span class="bold"><strong>Throws</strong></span>: <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code>
|
|
if the complexity of matching the expression against an N character string
|
|
begins to exceed O(N<sup>2</sup>), or if the program runs out of stack space while
|
|
matching the expression (if Boost.Regex is configured in recursive mode),
|
|
or if the matcher exhausts its permitted memory allocation (if Boost.Regex
|
|
is configured in non-recursive mode).
|
|
</p>
|
|
<p>
|
|
<span class="bold"><strong>Example</strong></span>: the following function will split
|
|
the input string into a series of tokens, and remove each token from the
|
|
string <span class="emphasis"><em>s</em></span>:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">unsigned</span> <span class="identifier">tokenise</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">>&</span> <span class="identifier">l</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">s</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">return</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex_split</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">back_inserter</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span> <span class="identifier">s</span><span class="special">);</span>
|
|
<span class="special">}</span>
|
|
</pre>
|
|
<p>
|
|
Example: the following short program will extract all of the URL's from
|
|
a html file, and print them out to cout:
|
|
</p>
|
|
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">list</span><span class="special">></span>
|
|
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">fstream</span><span class="special">></span>
|
|
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span>
|
|
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
|
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e</span><span class="special">(</span><span class="string">"<\\s*A\\s+[^>]*href\\s*=\\s*\"([^\"]*)\""</span><span class="special">,</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regbase</span><span class="special">::</span><span class="identifier">normal</span> <span class="special">|</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regbase</span><span class="special">::</span><span class="identifier">icase</span><span class="special">);</span>
|
|
|
|
<span class="keyword">void</span> <span class="identifier">load_file</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">s</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&</span> <span class="identifier">is</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">s</span><span class="special">.</span><span class="identifier">erase</span><span class="special">();</span>
|
|
<span class="comment">//</span>
|
|
<span class="comment">// attempt to grow string buffer to match file size,</span>
|
|
<span class="comment">// this doesn't always work...</span>
|
|
<span class="identifier">s</span><span class="special">.</span><span class="identifier">reserve</span><span class="special">(</span><span class="identifier">is</span><span class="special">.</span><span class="identifier">rdbuf</span><span class="special">()-&</span><span class="identifier">gtin_avail</span><span class="special">());</span>
|
|
<span class="keyword">char</span> <span class="identifier">c</span><span class="special">;</span>
|
|
<span class="keyword">while</span><span class="special">(</span><span class="identifier">is</span><span class="special">.</span><span class="identifier">get</span><span class="special">(</span><span class="identifier">c</span><span class="special">))</span>
|
|
<span class="special">{</span>
|
|
<span class="comment">// use logarithmic growth strategy, in case</span>
|
|
<span class="comment">// in_avail (above) returned zero:</span>
|
|
<span class="keyword">if</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">capacity</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">())</span>
|
|
<span class="identifier">s</span><span class="special">.</span><span class="identifier">reserve</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">capacity</span><span class="special">()</span> <span class="special">*</span> <span class="number">3</span><span class="special">);</span>
|
|
<span class="identifier">s</span><span class="special">.</span><span class="identifier">append</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="identifier">c</span><span class="special">);</span>
|
|
<span class="special">}</span>
|
|
<span class="special">}</span>
|
|
|
|
|
|
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">**</span> <span class="identifier">argv</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">s</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="identifier">l</span><span class="special">;</span>
|
|
|
|
<span class="keyword">for</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">1</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">argc</span><span class="special">;</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Findings URL's in "</span> <span class="special"><<</span> <span class="identifier">argv</span><span class="special">[</span><span class="identifier">i</span><span class="special">]</span> <span class="special"><<</span> <span class="string">":"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
|
|
<span class="identifier">s</span><span class="special">.</span><span class="identifier">erase</span><span class="special">();</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">ifstream</span> <span class="identifier">is</span><span class="special">(</span><span class="identifier">argv</span><span class="special">[</span><span class="identifier">i</span><span class="special">]);</span>
|
|
<span class="identifier">load_file</span><span class="special">(</span><span class="identifier">s</span><span class="special">,</span> <span class="identifier">is</span><span class="special">);</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex_split</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">back_inserter</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span> <span class="identifier">s</span><span class="special">,</span> <span class="identifier">e</span><span class="special">);</span>
|
|
<span class="keyword">while</span><span class="special">(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">size</span><span class="special">())</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">s</span> <span class="special">=</span> <span class="special">*(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">());</span>
|
|
<span class="identifier">l</span><span class="special">.</span><span class="identifier">pop_front</span><span class="special">();</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">s</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
<span class="special">}</span>
|
|
<span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
</pre>
|
|
</div>
|
|
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
|
<td align="left"></td>
|
|
<td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p>
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
|
</p>
|
|
</div></td>
|
|
</tr></table>
|
|
<hr>
|
|
<div class="spirit-nav">
|
|
<a accesskey="p" href="regex_grep.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../deprecated.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="old_regex.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
|
|
</div>
|
|
</body>
|
|
</html>
|