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  <title>Introduction</title>
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  <p><img src="../../boost.png" alt="C++ Boost" width="277" height=
  "86"/><br></p>

  <h1 align="center">Introduction</h1>

  <p align="left">The Boost Tokenizer package provides a flexible and 
  easy-to-use way to break a string or other character sequence into a series
  of tokens. Below is a simple example that will break up a phrase into
  words.</p>

  <div align="left">
    <pre>
// simple_example_1.cpp
#include&lt;iostream&gt;
#include&lt;boost/tokenizer.hpp&gt;
#include&lt;string&gt;

int main(){
   using namespace std;
   using namespace boost;
   string s = "This is,  a test";
   tokenizer&lt;&gt; tok(s);
   for(tokenizer&lt;&gt;::iterator beg=tok.begin(); beg!=tok.end();++beg){
       cout &lt;&lt; *beg &lt;&lt; "\n";
   }
}
</pre>
  </div>

  <p align="left">You can choose how the string gets parsed by using the
  TokenizerFunction. If you do not specify anything, the default
  TokenizerFunction is <em>char_delimiters_separator&lt;char&gt;</em> which
  defaults to breaking up a string based on space and punctuation. Here is an
  example using another TokenizerFunction called
  <em>escaped_list_separator</em>. This TokenizerFunction parses a superset
  of comma-separated value (CSV) lines. The format looks like this:</p>

  <p align="left">Field 1,"putting quotes around fields, allows commas",Field
  3</p>

  <p align="left">Below is an example that will break the previous line into
  its three fields.</p>

  <div align="left">
    <pre>
// simple_example_2.cpp
#include&lt;iostream&gt;
#include&lt;boost/tokenizer.hpp&gt;
#include&lt;string&gt;

int main(){
   using namespace std;
   using namespace boost;
   string s = "Field 1,\"putting quotes around fields, allows commas\",Field 3";
   tokenizer&lt;escaped_list_separator&lt;char&gt; &gt; tok(s);
   for(tokenizer&lt;escaped_list_separator&lt;char&gt; &gt;::iterator beg=tok.begin(); beg!=tok.end();++beg){
       cout &lt;&lt; *beg &lt;&lt; "\n";
   }
}
</pre>
  </div>

  <p align="left">Finally, for some TokenizerFunctions you have to pass
  something into the constructor in order to do anything interesting. An
  example is the offset_separator. This class breaks a string into tokens based
  on offsets. For example, when <em>12252001</em> is parsed using offsets of
  2,2,4 it becomes <em>12 25 2001</em>. Below is the code used.</p>

  <div align="left">
    <pre>
// simple_example_3.cpp
#include&lt;iostream&gt;
#include&lt;boost/tokenizer.hpp&gt;
#include&lt;string&gt;

int main(){
   using namespace std;
   using namespace boost;
   string s = "12252001";
   int offsets[] = {2,2,4};
   offset_separator f(offsets, offsets+3);
   tokenizer&lt;offset_separator&gt; tok(s,f);
   for(tokenizer&lt;offset_separator&gt;::iterator beg=tok.begin(); beg!=tok.end();++beg){
       cout &lt;&lt; *beg &lt;&lt; "\n";
   }
}
</pre>
  </div>

  <p align="left">&nbsp;</p>
  <hr>

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  <p>Revised 
  <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B %Y" startspan -->9 June 2010<!--webbot bot="Timestamp" endspan i-checksum="38518" --></p>

  <p><i>Copyright &copy; 2001 John R. Bandela</i></p>

  <p><i>Distributed under the Boost Software License, Version 1.0. (See
  accompanying file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  copy at <a href=
  "http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</i></p>
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