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<div class="titlepage"><div><div><h4 class="title">
<a name="spirit.karma.quick_reference.phoenix"></a><a class="link" href="phoenix.html" title="Phoenix">Phoenix</a>
</h4></div></div></div>
<p>
<a href="../../../../../phoenix/doc/html/index.html" target="_top">Boost.Phoenix</a> makes
it easier to attach semantic actions. You just inline your lambda expressions:
</p>
<pre class="programlisting"><span class="identifier">g</span><span class="special">[</span><span class="identifier">phoenix</span><span class="special">-</span><span class="identifier">lambda</span><span class="special">-</span><span class="identifier">expression</span><span class="special">]</span>
</pre>
<p>
<span class="emphasis"><em>Spirit.Karma</em></span> provides some <a href="../../../../../phoenix/doc/html/index.html" target="_top">Boost.Phoenix</a>
placeholders to access important information from the <code class="computeroutput"><span class="identifier">Attrib</span></code>
and <code class="computeroutput"><span class="identifier">Context</span></code> that are otherwise
fiddly to extract.
</p>
<div class="variablelist">
<p class="title"><b>Spirit.Karma specific Phoenix placeholders</b></p>
<dl>
<dt><span class="term"><code class="computeroutput"><span class="identifier">_1</span><span class="special">,</span>
<span class="identifier">_2</span><span class="special">,</span>
<span class="special">...</span> <span class="special">,</span>
<span class="identifier">_N</span></code></span></dt>
<dd><p>
Nth attribute of <code class="computeroutput"><span class="identifier">g</span></code>
</p></dd>
<dt><span class="term"><code class="computeroutput"><span class="identifier">_val</span></code></span></dt>
<dd><p>
The enclosing rule's synthesized attribute.
</p></dd>
<dt><span class="term"><code class="computeroutput"><span class="identifier">_r1</span><span class="special">,</span>
<span class="identifier">_r2</span><span class="special">,</span>
<span class="special">...</span> <span class="special">,</span>
<span class="identifier">_rN</span></code></span></dt>
<dd><p>
The enclosing rule's Nth inherited attribute.
</p></dd>
<dt><span class="term"><code class="computeroutput"><span class="identifier">_a</span><span class="special">,</span>
<span class="identifier">_b</span><span class="special">,</span>
<span class="special">...</span> <span class="special">,</span>
<span class="identifier">_j</span></code></span></dt>
<dd><p>
The enclosing rule's local variables (<code class="computeroutput"><span class="identifier">_a</span></code>
refers to the first).
</p></dd>
<dt><span class="term"><code class="computeroutput"><span class="identifier">_pass</span></code></span></dt>
<dd><p>
Assign <code class="computeroutput"><span class="keyword">false</span></code> to <code class="computeroutput"><span class="identifier">_pass</span></code> to force a generator failure.
</p></dd>
</dl>
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<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../images/important.png"></td>
<th align="left">Important</th>
</tr>
<tr><td align="left" valign="top"><p>
All placeholders mentioned above are defined in the namespace <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span></code> and, for your convenience, are
available in the namespace <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">karma</span></code>
as well.
</p></td></tr>
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<p>
For more information see <a class="link" href="../tutorials/semantic_actions.html" title="Semantic Actions">Semantic
Actions</a>.
</p>
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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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