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<div class="titlepage"><div><div><h5 class="title">
<a name="spirit.qi.quick_reference.qi_parsers.operator"></a><a class="link" href="operator.html" title="Parser Operators"> Parser
Operators</a>
</h5></div></div></div>
<div class="informaltable"><table class="table">
<colgroup>
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<thead><tr>
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<p>
Expression
</p>
</th>
<th>
<p>
Attribute
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
<code class="computeroutput"><span class="special">!</span><span class="identifier">a</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">Unused</span></code>
</p>
</td>
<td>
<p>
Not predicate. If the predicate <code class="computeroutput"><span class="identifier">a</span></code>
matches, fail. Otherwise, return a zero length match.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="special">&</span><span class="identifier">a</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">Unused</span></code>
</p>
</td>
<td>
<p>
And predicate. If the predicate <code class="computeroutput"><span class="identifier">a</span></code>
matches, return a zero length match. Otherwise, fail.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="special">-</span><span class="identifier">a</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Optional. Parse <code class="computeroutput"><span class="identifier">a</span></code>
zero or one time
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="special">*</span><span class="identifier">a</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Kleene. Parse <code class="computeroutput"><span class="identifier">a</span></code>
zero or more times
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="special">+</span><span class="identifier">a</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Plus. Parse <code class="computeroutput"><span class="identifier">a</span></code>
one or more times
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">|</span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">variant</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span>
<span class="identifier">B</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Alternative. Parse <code class="computeroutput"><span class="identifier">a</span></code>
or <code class="computeroutput"><span class="identifier">b</span></code>
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">>></span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">tuple</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span>
<span class="identifier">B</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Sequence. Parse <code class="computeroutput"><span class="identifier">a</span></code>
followed by <code class="computeroutput"><span class="identifier">b</span></code>
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">></span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">tuple</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span>
<span class="identifier">B</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
Expect. Parse <code class="computeroutput"><span class="identifier">a</span></code>
followed by <code class="computeroutput"><span class="identifier">b</span></code>.
<code class="computeroutput"><span class="identifier">b</span></code> is expected
to match when <code class="computeroutput"><span class="identifier">a</span></code>
matches, otherwise, an <code class="computeroutput"><span class="identifier">expectation_failure</span></code>
is thrown.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">-</span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">A</span></code>
</p>
</td>
<td>
<p>
Difference. Parse <code class="computeroutput"><span class="identifier">a</span></code>
but not <code class="computeroutput"><span class="identifier">b</span></code>
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">||</span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">tuple</span><span class="special"><</span></code>
<code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">A</span><span class="special">>,</span></code>
<code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span>
<span class="special">></span></code>
</p>
</td>
<td>
<p>
Sequential Or. Parse <code class="computeroutput"><span class="identifier">a</span></code>
or <code class="computeroutput"><span class="identifier">b</span></code> or <code class="computeroutput"><span class="identifier">a</span></code> followed by <code class="computeroutput"><span class="identifier">b</span></code>
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">%</span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span></code>
</p>
</td>
<td>
<p>
List. Parse <code class="computeroutput"><span class="identifier">a</span></code>
delimited <code class="computeroutput"><span class="identifier">b</span></code>
one or more times
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">a</span> <span class="special">^</span>
<span class="identifier">b</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">tuple</span><span class="special"><</span></code>
<code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">A</span><span class="special">>,</span></code>
<code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span>
<span class="special">></span></code>
</p>
</td>
<td>
<p>
Permutation. Parse <code class="computeroutput"><span class="identifier">a</span></code>
or <code class="computeroutput"><span class="identifier">b</span></code> or <code class="computeroutput"><span class="identifier">a</span></code> followed by <code class="computeroutput"><span class="identifier">b</span></code> or <code class="computeroutput"><span class="identifier">b</span></code>
followed by <code class="computeroutput"><span class="identifier">a</span></code>.
</p>
</td>
</tr>
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<td align="right"><div class="copyright-footer">Copyright © 2001-2010 Joel de Guzman, Hartmut Kaiser<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>)
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