<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<!--
This file was generated by Devel::NYTProf version 3.11
-->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="Content-Language" content="en-us" />
<title>Profile of /usr/local/lib/perl5/5.10.1/darwin-2level/mro.pm</title>
<link rel="stylesheet" type="text/css" href="style.css" />
<script type="text/javascript" src="js/jquery-min.js"></script>
<script type="text/javascript" src="js/jquery-tablesorter-min.js"></script>
<link rel="stylesheet" type="text/css" href="js/style-tablesorter.css" />
<script type="text/javascript">
// when a column is first clicked on to sort it, use descending order
// XXX doesn't seem to work (and not just because the tablesorter formatSortingOrder() is broken)
$.tablesorter.defaults.sortInitialOrder = "desc";
// add parser through the tablesorter addParser method
$.tablesorter.addParser({
id: 'fmt_time', // name of this parser
is: function(s) {
return false; // return false so this parser is not auto detected
},
format: function(orig) { // format data for normalization
// console.log(orig);
val = orig.replace(/ns/,'');
if (val != orig) { return val / (1000*1000*1000); }
val = orig.replace(/µs/,''); /* XXX use µ ? */
if (val != orig) { return val / (1000*1000); }
var val = orig.replace(/ms/,'');
if (val != orig) { return val / (1000); }
var val = orig.replace(/s/,'');
if (val != orig) { return val; }
if (orig == '0') { return orig; }
console.log('no match for fmt_time of '.concat(orig));
return orig;
},
type: 'numeric' // set type, either numeric or text
});
</script>
</head>
<body >
<div class="header" style="position: relative; overflow-x: hidden; overflow-y: hidden; z-index: 0; ">
<div class="header_back">
<a href="index.html">← Index</a>
</div>
<div class="headerForeground" style="float: left">
<span class="siteTitle">NYTProf Performance Profile</span>
<span class="siteSubtitle">  <span>« <span class="mode_btn"><a href="mro-pm-block.html">block view</a></span> • <span class="mode_btn"><a href="mro-pm-line.html">line view</a></span> • <span class="mode_btn mode_btn_selected">sub view</span> »</span><br />
For 01.HTTP.t
</span>
</div>
<div class="headerForeground" style="float: right; text-align: right">
<span class="siteTitle"> </span>
<span class="siteSubtitle">Run on Tue May 4 15:25:55 2010<br />Reported on Tue May 4 15:26:05 2010</span>
</div>
<div style="position: absolute; left: 0px; top: 0%; width: 100%; height: 101%; z-index: -1; background-color: rgb(17, 136, 255); "></div>
<div style="position: absolute; left: 0px; top: 2%; width: 100%; height: 99%; z-index: -1; background-color: rgb(16, 134, 253); "></div>
<div style="position: absolute; left: 0px; top: 4%; width: 100%; height: 97%; z-index: -1; background-color: rgb(16, 133, 252); "></div>
<div style="position: absolute; left: 0px; top: 6%; width: 100%; height: 95%; z-index: -1; background-color: rgb(15, 131, 250); "></div>
<div style="position: absolute; left: 0px; top: 8%; width: 100%; height: 93%; z-index: -1; background-color: rgb(15, 130, 249); "></div>
<div style="position: absolute; left: 0px; top: 10%; width: 100%; height: 91%; z-index: -1; background-color: rgb(15, 129, 248); "></div>
<div style="position: absolute; left: 0px; top: 12%; width: 100%; height: 89%; z-index: -1; background-color: rgb(14, 127, 246); "></div>
<div style="position: absolute; left: 0px; top: 14%; width: 100%; height: 87%; z-index: -1; background-color: rgb(14, 126, 245); "></div>
<div style="position: absolute; left: 0px; top: 16%; width: 100%; height: 85%; z-index: -1; background-color: rgb(14, 125, 244); "></div>
<div style="position: absolute; left: 0px; top: 18%; width: 100%; height: 83%; z-index: -1; background-color: rgb(13, 123, 242); "></div>
<div style="position: absolute; left: 0px; top: 20%; width: 100%; height: 81%; z-index: -1; background-color: rgb(13, 122, 241); "></div>
<div style="position: absolute; left: 0px; top: 22%; width: 100%; height: 79%; z-index: -1; background-color: rgb(13, 121, 240); "></div>
<div style="position: absolute; left: 0px; top: 24%; width: 100%; height: 77%; z-index: -1; background-color: rgb(12, 119, 238); "></div>
<div style="position: absolute; left: 0px; top: 26%; width: 100%; height: 75%; z-index: -1; background-color: rgb(12, 118, 237); "></div>
<div style="position: absolute; left: 0px; top: 28%; width: 100%; height: 73%; z-index: -1; background-color: rgb(12, 116, 235); "></div>
<div style="position: absolute; left: 0px; top: 30%; width: 100%; height: 71%; z-index: -1; background-color: rgb(11, 115, 234); "></div>
<div style="position: absolute; left: 0px; top: 32%; width: 100%; height: 69%; z-index: -1; background-color: rgb(11, 114, 233); "></div>
<div style="position: absolute; left: 0px; top: 34%; width: 100%; height: 67%; z-index: -1; background-color: rgb(11, 112, 231); "></div>
<div style="position: absolute; left: 0px; top: 36%; width: 100%; height: 65%; z-index: -1; background-color: rgb(10, 111, 230); "></div>
<div style="position: absolute; left: 0px; top: 38%; width: 100%; height: 63%; z-index: -1; background-color: rgb(10, 110, 229); "></div>
<div style="position: absolute; left: 0px; top: 40%; width: 100%; height: 61%; z-index: -1; background-color: rgb(10, 108, 227); "></div>
<div style="position: absolute; left: 0px; top: 42%; width: 100%; height: 59%; z-index: -1; background-color: rgb(9, 107, 226); "></div>
<div style="position: absolute; left: 0px; top: 44%; width: 100%; height: 57%; z-index: -1; background-color: rgb(9, 106, 225); "></div>
<div style="position: absolute; left: 0px; top: 46%; width: 100%; height: 55%; z-index: -1; background-color: rgb(9, 104, 223); "></div>
<div style="position: absolute; left: 0px; top: 48%; width: 100%; height: 53%; z-index: -1; background-color: rgb(8, 103, 222); "></div>
<div style="position: absolute; left: 0px; top: 50%; width: 100%; height: 51%; z-index: -1; background-color: rgb(8, 102, 221); "></div>
<div style="position: absolute; left: 0px; top: 52%; width: 100%; height: 49%; z-index: -1; background-color: rgb(8, 100, 219); "></div>
<div style="position: absolute; left: 0px; top: 54%; width: 100%; height: 47%; z-index: -1; background-color: rgb(7, 99, 218); "></div>
<div style="position: absolute; left: 0px; top: 56%; width: 100%; height: 45%; z-index: -1; background-color: rgb(7, 97, 216); "></div>
<div style="position: absolute; left: 0px; top: 58%; width: 100%; height: 43%; z-index: -1; background-color: rgb(7, 96, 215); "></div>
<div style="position: absolute; left: 0px; top: 60%; width: 100%; height: 41%; z-index: -1; background-color: rgb(6, 95, 214); "></div>
<div style="position: absolute; left: 0px; top: 62%; width: 100%; height: 39%; z-index: -1; background-color: rgb(6, 93, 212); "></div>
<div style="position: absolute; left: 0px; top: 64%; width: 100%; height: 37%; z-index: -1; background-color: rgb(6, 92, 211); "></div>
<div style="position: absolute; left: 0px; top: 66%; width: 100%; height: 35%; z-index: -1; background-color: rgb(5, 91, 210); "></div>
<div style="position: absolute; left: 0px; top: 68%; width: 100%; height: 33%; z-index: -1; background-color: rgb(5, 89, 208); "></div>
<div style="position: absolute; left: 0px; top: 70%; width: 100%; height: 31%; z-index: -1; background-color: rgb(5, 88, 207); "></div>
<div style="position: absolute; left: 0px; top: 72%; width: 100%; height: 29%; z-index: -1; background-color: rgb(4, 87, 206); "></div>
<div style="position: absolute; left: 0px; top: 74%; width: 100%; height: 27%; z-index: -1; background-color: rgb(4, 85, 204); "></div>
<div style="position: absolute; left: 0px; top: 76%; width: 100%; height: 25%; z-index: -1; background-color: rgb(4, 84, 203); "></div>
<div style="position: absolute; left: 0px; top: 78%; width: 100%; height: 23%; z-index: -1; background-color: rgb(3, 82, 201); "></div>
<div style="position: absolute; left: 0px; top: 80%; width: 100%; height: 21%; z-index: -1; background-color: rgb(3, 81, 200); "></div>
<div style="position: absolute; left: 0px; top: 82%; width: 100%; height: 19%; z-index: -1; background-color: rgb(3, 80, 199); "></div>
<div style="position: absolute; left: 0px; top: 84%; width: 100%; height: 17%; z-index: -1; background-color: rgb(2, 78, 197); "></div>
<div style="position: absolute; left: 0px; top: 86%; width: 100%; height: 15%; z-index: -1; background-color: rgb(2, 77, 196); "></div>
<div style="position: absolute; left: 0px; top: 88%; width: 100%; height: 13%; z-index: -1; background-color: rgb(2, 76, 195); "></div>
<div style="position: absolute; left: 0px; top: 90%; width: 100%; height: 11%; z-index: -1; background-color: rgb(1, 74, 193); "></div>
<div style="position: absolute; left: 0px; top: 92%; width: 100%; height: 9%; z-index: -1; background-color: rgb(1, 73, 192); "></div>
<div style="position: absolute; left: 0px; top: 94%; width: 100%; height: 7%; z-index: -1; background-color: rgb(1, 72, 191); "></div>
<div style="position: absolute; left: 0px; top: 96%; width: 100%; height: 5%; z-index: -1; background-color: rgb(0, 70, 189); "></div>
<div style="position: absolute; left: 0px; top: 98%; width: 100%; height: 3%; z-index: -1; background-color: rgb(0, 69, 188); "></div>
<div style="position: absolute; left: 0px; top: 100%; width: 100%; height: 1%; z-index: -1; background-color: rgb(0, 68, 187); "></div>
</div>
<div class="body_content">
<br />
<table>
<tr>
<td class="h" align="right">File</td>
<td align="left">/usr/local/lib/perl5/5.10.1/darwin-2level/mro.pm</td>
</tr>
<tr>
<td class="h" align="right">Statements Executed</td>
<td align="left">10</td>
</tr>
<tr>
<td class="h" align="right">Statement Execution Time</td>
<td align="left">324µs</td>
</tr>
</table>
<table id="subs_table" border="1" cellpadding="0" class="tablesorter">
<caption>Subroutines — ordered by exclusive time</caption>
<thead>
<tr>
<th>Calls</th>
<th><span title="Number of Places sub is called from">P</span></th>
<th><span title="Number of Files sub is called from">F</span></th>
<th>Exclusive<br />Time</th>
<th>Inclusive<br />Time</th>
<th>Subroutine</th>
</tr>
</thead>
<tbody>
<tr><td class="c1">218</td><td class="c1">2</td><td class="c1">3</td><td class="c0"><span title="0.0%">368µs</span></td><td class="c0"><span title="0.0%">368µs</span></td><td class="sub_name"><span style="display: none;">mro::::get_linear_isa</span> mro::<a href="mro-pm-sub.html#mro__get_linear_isa">get_linear_isa</a> (xsub)</span></td></tr>
<tr><td class="c3">86</td><td class="c3">1</td><td class="c3">2</td><td class="c3"><span title="0.0%">117µs</span></td><td class="c3"><span title="0.0%">117µs</span></td><td class="sub_name"><span style="display: none;">mro::::method_changed_in</span> mro::<a href="mro-pm-sub.html#mro__method_changed_in">method_changed_in</a> (xsub)</span></td></tr>
<tr><td class="c3">1</td><td class="c3">1</td><td class="c3">1</td><td class="c3"><span title="0.0%">18µs</span></td><td class="c3"><span title="0.0%">20µs</span></td><td class="sub_name"><span style="display: none;">mro::::BEGIN@10</span> mro::<a href="mro-pm-sub.html#10">BEGIN@10</a></span></td></tr>
<tr><td class="c3">1</td><td class="c3">1</td><td class="c3">1</td><td class="c3"><span title="0.0%">7µs</span></td><td class="c3"><span title="0.0%">15µs</span></td><td class="sub_name"><span style="display: none;">mro::::BEGIN@11</span> mro::<a href="mro-pm-sub.html#11">BEGIN@11</a></span></td></tr>
<tr><td class="c3">0</td><td class="c3">0</td><td class="c3">0</td><td class="c3"><span title="0.0%">0s</span></td><td class="c3"><span title="0.0%">0s</span></td><td class="sub_name"><span style="display: none;">maybe::next::::method</span>maybe::next::<a href="mro-pm-sub.html#34">method</a></span></td></tr>
<tr><td class="c3">0</td><td class="c3">0</td><td class="c3">0</td><td class="c3"><span title="0.0%">0s</span></td><td class="c3"><span title="0.0%">0s</span></td><td class="sub_name"><span style="display: none;">mro::::import</span> mro::<a href="mro-pm-sub.html#17">import</a></span></td></tr>
<tr><td class="c3">0</td><td class="c3">0</td><td class="c3">0</td><td class="c3"><span title="0.0%">0s</span></td><td class="c3"><span title="0.0%">0s</span></td><td class="sub_name"><span style="display: none;">next::::can</span> next::<a href="mro-pm-sub.html#24">can</a></span></td></tr>
<tr><td class="c3">0</td><td class="c3">0</td><td class="c3">0</td><td class="c3"><span title="0.0%">0s</span></td><td class="c3"><span title="0.0%">0s</span></td><td class="sub_name"><span style="display: none;">next::::method</span> next::<a href="mro-pm-sub.html#26">method</a></span></td></tr>
</tbody>
</table>
Call graph for these subroutines as a <a href="http://en.wikipedia.org/wiki/Graphviz">Graphviz</a> <a href="usr-local-lib-perl5-5-10-1-darwin-2level-mro-pm.dot">dot language file</a>.
<table border="1" cellpadding="0">
<thead>
<tr><th>Line</th>
<th><span title="Number of statements executed">State<br />ments</span></th>
<th><span title="Time spend executing statements on the line,
excluding time spent executing statements in any called subroutines">Time<br />on line</span></th>
<th><span title="Number of subroutines calls">Calls</span></th>
<th><span title="Time spent in subroutines called">Time<br />in subs</span></th>
<th class="left_indent_header">Code</th>
</tr>
</thead>
<tbody>
<tr><td class="h"><a name="1"></a>1</td><td></td><td></td><td></td><td></td><td class="s"># mro.pm</td></tr>
<tr><td class="h"><a name="2"></a>2</td><td></td><td></td><td></td><td></td><td class="s">#</td></tr>
<tr><td class="h"><a name="3"></a>3</td><td></td><td></td><td></td><td></td><td class="s"># Copyright (c) 2007 Brandon L Black</td></tr>
<tr><td class="h"><a name="4"></a>4</td><td></td><td></td><td></td><td></td><td class="s"># Copyright (c) 2008 Larry Wall and others</td></tr>
<tr><td class="h"><a name="5"></a>5</td><td></td><td></td><td></td><td></td><td class="s">#</td></tr>
<tr><td class="h"><a name="6"></a>6</td><td></td><td></td><td></td><td></td><td class="s"># You may distribute under the terms of either the GNU General Public</td></tr>
<tr><td class="h"><a name="7"></a>7</td><td></td><td></td><td></td><td></td><td class="s"># License or the Artistic License, as specified in the README file.</td></tr>
<tr><td class="h"><a name="8"></a>8</td><td></td><td></td><td></td><td></td><td class="s">#</td></tr>
<tr><td class="h"><a name="9"></a>9</td><td></td><td></td><td></td><td></td><td class="s">package mro;</td></tr>
<tr><td class="h"><a name="10"></a>10</td><td class="c0">3</td><td class="c3"><span title="Avg 7µs">20µs</span></td><td class="c3">2</td><td class="c3">23µs</td><td class="s"><div class="calls"><div class="calls_in"># spent 20µs (18+3) within mro::BEGIN@10 which was called
# once (18µs+3µs) by MRO::Compat::BEGIN@10 at <a href="mro-pm-sub.html#10">line 10</a></div></div>use strict;<div class="calls"><div class="calls_out"># spent 20µs making 1 call to <a href="mro-pm-sub.html#10">mro::BEGIN@10</a>
# spent 3µs making 1 call to <a href="strict-pm-sub.html#34">strict::import</a></div></div></td></tr>
<tr><td class="h"><a name="11"></a>11</td><td class="c0">3</td><td class="c0"><span title="Avg 44µs">133µs</span></td><td class="c3">2</td><td class="c3">24µs</td><td class="s"><div class="calls"><div class="calls_in"># spent 15µs (7+9) within mro::BEGIN@11 which was called
# once (7µs+9µs) by MRO::Compat::BEGIN@10 at <a href="mro-pm-sub.html#11">line 11</a></div></div>use warnings;<div class="calls"><div class="calls_out"># spent 15µs making 1 call to <a href="mro-pm-sub.html#11">mro::BEGIN@11</a>
# spent 9µs making 1 call to <a href="warnings-pm-sub.html#338">warnings::import</a></div></div></td></tr>
<tr><td class="h"><a name="12"></a>12</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="13"></a>13</td><td></td><td></td><td></td><td></td><td class="s"># mro.pm versions < 1.00 reserved for MRO::Compat</td></tr>
<tr><td class="h"><a name="14"></a>14</td><td></td><td></td><td></td><td></td><td class="s"># for partial back-compat to 5.[68].x</td></tr>
<tr><td class="h"><a name="15"></a>15</td><td class="c3">1</td><td class="c3"><span title="Avg 700ns">700ns</span></td><td></td><td></td><td class="s">our $VERSION = '1.01';</td></tr>
<tr><td class="h"><a name="16"></a>16</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="17"></a>17</td><td></td><td></td><td></td><td></td><td class="s">sub import {</td></tr>
<tr><td class="h"><a name="18"></a>18</td><td></td><td></td><td></td><td></td><td class="s"> mro::set_mro(scalar(caller), $_[1]) if $_[1];</td></tr>
<tr><td class="h"><a name="19"></a>19</td><td></td><td></td><td></td><td></td><td class="s">}</td></tr>
<tr><td class="h"><a name="20"></a>20</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="21"></a>21</td><td></td><td></td><td></td><td></td><td class="s">package # hide me from PAUSE</td></tr>
<tr><td class="h"><a name="22"></a>22</td><td></td><td></td><td></td><td></td><td class="s"> next;</td></tr>
<tr><td class="h"><a name="23"></a>23</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="24"></a>24</td><td></td><td></td><td></td><td></td><td class="s">sub can { mro::_nextcan($_[0], 0) }</td></tr>
<tr><td class="h"><a name="25"></a>25</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="26"></a>26</td><td></td><td></td><td></td><td></td><td class="s">sub method {</td></tr>
<tr><td class="h"><a name="27"></a>27</td><td></td><td></td><td></td><td></td><td class="s"> my $method = mro::_nextcan($_[0], 1);</td></tr>
<tr><td class="h"><a name="28"></a>28</td><td></td><td></td><td></td><td></td><td class="s"> goto &$method;</td></tr>
<tr><td class="h"><a name="29"></a>29</td><td></td><td></td><td></td><td></td><td class="s">}</td></tr>
<tr><td class="h"><a name="30"></a>30</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="31"></a>31</td><td></td><td></td><td></td><td></td><td class="s">package # hide me from PAUSE</td></tr>
<tr><td class="h"><a name="32"></a>32</td><td></td><td></td><td></td><td></td><td class="s"> maybe::next;</td></tr>
<tr><td class="h"><a name="33"></a>33</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="34"></a>34</td><td></td><td></td><td></td><td></td><td class="s">sub method {</td></tr>
<tr><td class="h"><a name="35"></a>35</td><td></td><td></td><td></td><td></td><td class="s"> my $method = mro::_nextcan($_[0], 0);</td></tr>
<tr><td class="h"><a name="36"></a>36</td><td></td><td></td><td></td><td></td><td class="s"> goto &$method if defined $method;</td></tr>
<tr><td class="h"><a name="37"></a>37</td><td></td><td></td><td></td><td></td><td class="s"> return;</td></tr>
<tr><td class="h"><a name="38"></a>38</td><td></td><td></td><td></td><td></td><td class="s">}</td></tr>
<tr><td class="h"><a name="39"></a>39</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="40"></a>40</td><td class="c3">1</td><td class="c3"><span title="Avg 500ns">500ns</span></td><td></td><td></td><td class="s">require XSLoader;</td></tr>
<tr><td class="h"><a name="41"></a>41</td><td class="c3">1</td><td class="c0"><span title="Avg 160µs">160µs</span></td><td class="c3">1</td><td class="c0">156µs</td><td class="s">XSLoader::load('mro', $VERSION);<div class="calls"><div class="calls_out"># spent 156µs making 1 call to <a href="XSLoader-pm-sub.html#22">XSLoader::load</a></div></div></td></tr>
<tr><td class="h"><a name="42"></a>42</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="43"></a>43</td><td class="c3">1</td><td class="c3"><span title="Avg 10µs">10µs</span></td><td></td><td></td><td class="s">1;</td></tr>
<tr><td class="h"><a name="44"></a>44</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="45"></a>45</td><td></td><td></td><td></td><td></td><td class="s">__END__</td></tr>
<tr><td class="h"><a name="46"></a>46</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="47"></a>47</td><td></td><td></td><td></td><td></td><td class="s">=head1 NAME</td></tr>
<tr><td class="h"><a name="48"></a>48</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="49"></a>49</td><td></td><td></td><td></td><td></td><td class="s">mro - Method Resolution Order</td></tr>
<tr><td class="h"><a name="50"></a>50</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="51"></a>51</td><td></td><td></td><td></td><td></td><td class="s">=head1 SYNOPSIS</td></tr>
<tr><td class="h"><a name="52"></a>52</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="53"></a>53</td><td></td><td></td><td></td><td></td><td class="s"> use mro; # enables next::method and friends globally</td></tr>
<tr><td class="h"><a name="54"></a>54</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="55"></a>55</td><td></td><td></td><td></td><td></td><td class="s"> use mro 'dfs'; # enable DFS MRO for this class (Perl default)</td></tr>
<tr><td class="h"><a name="56"></a>56</td><td></td><td></td><td></td><td></td><td class="s"> use mro 'c3'; # enable C3 MRO for this class</td></tr>
<tr><td class="h"><a name="57"></a>57</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="58"></a>58</td><td></td><td></td><td></td><td></td><td class="s">=head1 DESCRIPTION</td></tr>
<tr><td class="h"><a name="59"></a>59</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="60"></a>60</td><td></td><td></td><td></td><td></td><td class="s">The "mro" namespace provides several utilities for dealing</td></tr>
<tr><td class="h"><a name="61"></a>61</td><td></td><td></td><td></td><td></td><td class="s">with method resolution order and method caching in general.</td></tr>
<tr><td class="h"><a name="62"></a>62</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="63"></a>63</td><td></td><td></td><td></td><td></td><td class="s">These interfaces are only available in Perl 5.9.5 and higher.</td></tr>
<tr><td class="h"><a name="64"></a>64</td><td></td><td></td><td></td><td></td><td class="s">See L<MRO::Compat> on CPAN for a mostly forwards compatible</td></tr>
<tr><td class="h"><a name="65"></a>65</td><td></td><td></td><td></td><td></td><td class="s">implementation for older Perls.</td></tr>
<tr><td class="h"><a name="66"></a>66</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="67"></a>67</td><td></td><td></td><td></td><td></td><td class="s">=head1 OVERVIEW</td></tr>
<tr><td class="h"><a name="68"></a>68</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="69"></a>69</td><td></td><td></td><td></td><td></td><td class="s">It's possible to change the MRO of a given class either by using C<use</td></tr>
<tr><td class="h"><a name="70"></a>70</td><td></td><td></td><td></td><td></td><td class="s">mro> as shown in the synopsis, or by using the L</mro::set_mro> function</td></tr>
<tr><td class="h"><a name="71"></a>71</td><td></td><td></td><td></td><td></td><td class="s">below.</td></tr>
<tr><td class="h"><a name="72"></a>72</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="73"></a>73</td><td></td><td></td><td></td><td></td><td class="s">The special methods C<next::method>, C<next::can>, and</td></tr>
<tr><td class="h"><a name="74"></a>74</td><td></td><td></td><td></td><td></td><td class="s">C<maybe::next::method> are not available until this C<mro> module</td></tr>
<tr><td class="h"><a name="75"></a>75</td><td></td><td></td><td></td><td></td><td class="s">has been loaded via C<use> or C<require>.</td></tr>
<tr><td class="h"><a name="76"></a>76</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="77"></a>77</td><td></td><td></td><td></td><td></td><td class="s">=head1 The C3 MRO</td></tr>
<tr><td class="h"><a name="78"></a>78</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="79"></a>79</td><td></td><td></td><td></td><td></td><td class="s">In addition to the traditional Perl default MRO (depth first</td></tr>
<tr><td class="h"><a name="80"></a>80</td><td></td><td></td><td></td><td></td><td class="s">search, called C<DFS> here), Perl now offers the C3 MRO as</td></tr>
<tr><td class="h"><a name="81"></a>81</td><td></td><td></td><td></td><td></td><td class="s">well. Perl's support for C3 is based on the work done in</td></tr>
<tr><td class="h"><a name="82"></a>82</td><td></td><td></td><td></td><td></td><td class="s">Stevan Little's module L<Class::C3>, and most of the C3-related</td></tr>
<tr><td class="h"><a name="83"></a>83</td><td></td><td></td><td></td><td></td><td class="s">documentation here is ripped directly from there.</td></tr>
<tr><td class="h"><a name="84"></a>84</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="85"></a>85</td><td></td><td></td><td></td><td></td><td class="s">=head2 What is C3?</td></tr>
<tr><td class="h"><a name="86"></a>86</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="87"></a>87</td><td></td><td></td><td></td><td></td><td class="s">C3 is the name of an algorithm which aims to provide a sane method</td></tr>
<tr><td class="h"><a name="88"></a>88</td><td></td><td></td><td></td><td></td><td class="s">resolution order under multiple inheritance. It was first introduced in</td></tr>
<tr><td class="h"><a name="89"></a>89</td><td></td><td></td><td></td><td></td><td class="s">the language Dylan (see links in the L</"SEE ALSO"> section), and then</td></tr>
<tr><td class="h"><a name="90"></a>90</td><td></td><td></td><td></td><td></td><td class="s">later adopted as the preferred MRO (Method Resolution Order) for the</td></tr>
<tr><td class="h"><a name="91"></a>91</td><td></td><td></td><td></td><td></td><td class="s">new-style classes in Python 2.3. Most recently it has been adopted as the</td></tr>
<tr><td class="h"><a name="92"></a>92</td><td></td><td></td><td></td><td></td><td class="s">"canonical" MRO for Perl 6 classes, and the default MRO for Parrot objects</td></tr>
<tr><td class="h"><a name="93"></a>93</td><td></td><td></td><td></td><td></td><td class="s">as well.</td></tr>
<tr><td class="h"><a name="94"></a>94</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="95"></a>95</td><td></td><td></td><td></td><td></td><td class="s">=head2 How does C3 work</td></tr>
<tr><td class="h"><a name="96"></a>96</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="97"></a>97</td><td></td><td></td><td></td><td></td><td class="s">C3 works by always preserving local precendence ordering. This essentially</td></tr>
<tr><td class="h"><a name="98"></a>98</td><td></td><td></td><td></td><td></td><td class="s">means that no class will appear before any of its subclasses. Take, for</td></tr>
<tr><td class="h"><a name="99"></a>99</td><td></td><td></td><td></td><td></td><td class="s">instance, the classic diamond inheritance pattern:</td></tr>
<tr><td class="h"><a name="100"></a>100</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="101"></a>101</td><td></td><td></td><td></td><td></td><td class="s"> <A></td></tr>
<tr><td class="h"><a name="102"></a>102</td><td></td><td></td><td></td><td></td><td class="s"> / \</td></tr>
<tr><td class="h"><a name="103"></a>103</td><td></td><td></td><td></td><td></td><td class="s"> <B> <C></td></tr>
<tr><td class="h"><a name="104"></a>104</td><td></td><td></td><td></td><td></td><td class="s"> \ /</td></tr>
<tr><td class="h"><a name="105"></a>105</td><td></td><td></td><td></td><td></td><td class="s"> <D></td></tr>
<tr><td class="h"><a name="106"></a>106</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="107"></a>107</td><td></td><td></td><td></td><td></td><td class="s">The standard Perl 5 MRO would be (D, B, A, C). The result being that B<A></td></tr>
<tr><td class="h"><a name="108"></a>108</td><td></td><td></td><td></td><td></td><td class="s">appears before B<C>, even though B<C> is the subclass of B<A>. The C3 MRO</td></tr>
<tr><td class="h"><a name="109"></a>109</td><td></td><td></td><td></td><td></td><td class="s">algorithm however, produces the following order: (D, B, C, A), which does</td></tr>
<tr><td class="h"><a name="110"></a>110</td><td></td><td></td><td></td><td></td><td class="s">not have this issue.</td></tr>
<tr><td class="h"><a name="111"></a>111</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="112"></a>112</td><td></td><td></td><td></td><td></td><td class="s">This example is fairly trivial; for more complex cases and a deeper</td></tr>
<tr><td class="h"><a name="113"></a>113</td><td></td><td></td><td></td><td></td><td class="s">explanation, see the links in the L</"SEE ALSO"> section.</td></tr>
<tr><td class="h"><a name="114"></a>114</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="115"></a>115</td><td></td><td></td><td></td><td></td><td class="s">=head1 Functions</td></tr>
<tr><td class="h"><a name="116"></a>116</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="117"></a>117</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::get_linear_isa($classname[, $type])</td></tr>
<tr><td class="h"><a name="118"></a>118</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="119"></a>119</td><td></td><td></td><td></td><td></td><td class="s">Returns an arrayref which is the linearized MRO of the given class.</td></tr>
<tr><td class="h"><a name="120"></a>120</td><td></td><td></td><td></td><td></td><td class="s">Uses whichever MRO is currently in effect for that class by default,</td></tr>
<tr><td class="h"><a name="121"></a>121</td><td></td><td></td><td></td><td></td><td class="s">or the given MRO (either C<c3> or C<dfs> if specified as C<$type>).</td></tr>
<tr><td class="h"><a name="122"></a>122</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="123"></a>123</td><td></td><td></td><td></td><td></td><td class="s">The linearized MRO of a class is an ordered array of all of the</td></tr>
<tr><td class="h"><a name="124"></a>124</td><td></td><td></td><td></td><td></td><td class="s">classes one would search when resolving a method on that class,</td></tr>
<tr><td class="h"><a name="125"></a>125</td><td></td><td></td><td></td><td></td><td class="s">starting with the class itself.</td></tr>
<tr><td class="h"><a name="126"></a>126</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="127"></a>127</td><td></td><td></td><td></td><td></td><td class="s">If the requested class doesn't yet exist, this function will still</td></tr>
<tr><td class="h"><a name="128"></a>128</td><td></td><td></td><td></td><td></td><td class="s">succeed, and return C<[ $classname ]></td></tr>
<tr><td class="h"><a name="129"></a>129</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="130"></a>130</td><td></td><td></td><td></td><td></td><td class="s">Note that C<UNIVERSAL> (and any members of C<UNIVERSAL>'s MRO) are not</td></tr>
<tr><td class="h"><a name="131"></a>131</td><td></td><td></td><td></td><td></td><td class="s">part of the MRO of a class, even though all classes implicitly inherit</td></tr>
<tr><td class="h"><a name="132"></a>132</td><td></td><td></td><td></td><td></td><td class="s">methods from C<UNIVERSAL> and its parents.</td></tr>
<tr><td class="h"><a name="133"></a>133</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="134"></a>134</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::set_mro($classname, $type)</td></tr>
<tr><td class="h"><a name="135"></a>135</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="136"></a>136</td><td></td><td></td><td></td><td></td><td class="s">Sets the MRO of the given class to the C<$type> argument (either</td></tr>
<tr><td class="h"><a name="137"></a>137</td><td></td><td></td><td></td><td></td><td class="s">C<c3> or C<dfs>).</td></tr>
<tr><td class="h"><a name="138"></a>138</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="139"></a>139</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::get_mro($classname)</td></tr>
<tr><td class="h"><a name="140"></a>140</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="141"></a>141</td><td></td><td></td><td></td><td></td><td class="s">Returns the MRO of the given class (either C<c3> or C<dfs>).</td></tr>
<tr><td class="h"><a name="142"></a>142</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="143"></a>143</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::get_isarev($classname)</td></tr>
<tr><td class="h"><a name="144"></a>144</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="145"></a>145</td><td></td><td></td><td></td><td></td><td class="s">Gets the C<mro_isarev> for this class, returned as an</td></tr>
<tr><td class="h"><a name="146"></a>146</td><td></td><td></td><td></td><td></td><td class="s">arrayref of class names. These are every class that "isa"</td></tr>
<tr><td class="h"><a name="147"></a>147</td><td></td><td></td><td></td><td></td><td class="s">the given class name, even if the isa relationship is</td></tr>
<tr><td class="h"><a name="148"></a>148</td><td></td><td></td><td></td><td></td><td class="s">indirect. This is used internally by the MRO code to</td></tr>
<tr><td class="h"><a name="149"></a>149</td><td></td><td></td><td></td><td></td><td class="s">keep track of method/MRO cache invalidations.</td></tr>
<tr><td class="h"><a name="150"></a>150</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="151"></a>151</td><td></td><td></td><td></td><td></td><td class="s">Currently, this list only grows, it never shrinks. This</td></tr>
<tr><td class="h"><a name="152"></a>152</td><td></td><td></td><td></td><td></td><td class="s">was a performance consideration (properly tracking and</td></tr>
<tr><td class="h"><a name="153"></a>153</td><td></td><td></td><td></td><td></td><td class="s">deleting isarev entries when someone removes an entry</td></tr>
<tr><td class="h"><a name="154"></a>154</td><td></td><td></td><td></td><td></td><td class="s">from an C<@ISA> is costly, and it doesn't happen often</td></tr>
<tr><td class="h"><a name="155"></a>155</td><td></td><td></td><td></td><td></td><td class="s">anyways). The fact that a class which no longer truly</td></tr>
<tr><td class="h"><a name="156"></a>156</td><td></td><td></td><td></td><td></td><td class="s">"isa" this class at runtime remains on the list should be</td></tr>
<tr><td class="h"><a name="157"></a>157</td><td></td><td></td><td></td><td></td><td class="s">considered a quirky implementation detail which is subject</td></tr>
<tr><td class="h"><a name="158"></a>158</td><td></td><td></td><td></td><td></td><td class="s">to future change. It shouldn't be an issue as long as</td></tr>
<tr><td class="h"><a name="159"></a>159</td><td></td><td></td><td></td><td></td><td class="s">you're looking at this list for the same reasons the</td></tr>
<tr><td class="h"><a name="160"></a>160</td><td></td><td></td><td></td><td></td><td class="s">core code does: as a performance optimization</td></tr>
<tr><td class="h"><a name="161"></a>161</td><td></td><td></td><td></td><td></td><td class="s">over having to search every class in existence.</td></tr>
<tr><td class="h"><a name="162"></a>162</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="163"></a>163</td><td></td><td></td><td></td><td></td><td class="s">As with C<mro::get_mro> above, C<UNIVERSAL> is special.</td></tr>
<tr><td class="h"><a name="164"></a>164</td><td></td><td></td><td></td><td></td><td class="s">C<UNIVERSAL> (and parents') isarev lists do not include</td></tr>
<tr><td class="h"><a name="165"></a>165</td><td></td><td></td><td></td><td></td><td class="s">every class in existence, even though all classes are</td></tr>
<tr><td class="h"><a name="166"></a>166</td><td></td><td></td><td></td><td></td><td class="s">effectively descendants for method inheritance purposes.</td></tr>
<tr><td class="h"><a name="167"></a>167</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="168"></a>168</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::is_universal($classname)</td></tr>
<tr><td class="h"><a name="169"></a>169</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="170"></a>170</td><td></td><td></td><td></td><td></td><td class="s">Returns a boolean status indicating whether or not</td></tr>
<tr><td class="h"><a name="171"></a>171</td><td></td><td></td><td></td><td></td><td class="s">the given classname is either C<UNIVERSAL> itself,</td></tr>
<tr><td class="h"><a name="172"></a>172</td><td></td><td></td><td></td><td></td><td class="s">or one of C<UNIVERSAL>'s parents by C<@ISA> inheritance.</td></tr>
<tr><td class="h"><a name="173"></a>173</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="174"></a>174</td><td></td><td></td><td></td><td></td><td class="s">Any class for which this function returns true is</td></tr>
<tr><td class="h"><a name="175"></a>175</td><td></td><td></td><td></td><td></td><td class="s">"universal" in the sense that all classes potentially</td></tr>
<tr><td class="h"><a name="176"></a>176</td><td></td><td></td><td></td><td></td><td class="s">inherit methods from it.</td></tr>
<tr><td class="h"><a name="177"></a>177</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="178"></a>178</td><td></td><td></td><td></td><td></td><td class="s">For similar reasons to C<isarev> above, this flag is</td></tr>
<tr><td class="h"><a name="179"></a>179</td><td></td><td></td><td></td><td></td><td class="s">permanent. Once it is set, it does not go away, even</td></tr>
<tr><td class="h"><a name="180"></a>180</td><td></td><td></td><td></td><td></td><td class="s">if the class in question really isn't universal anymore.</td></tr>
<tr><td class="h"><a name="181"></a>181</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="182"></a>182</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::invalidate_all_method_caches()</td></tr>
<tr><td class="h"><a name="183"></a>183</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="184"></a>184</td><td></td><td></td><td></td><td></td><td class="s">Increments C<PL_sub_generation>, which invalidates method</td></tr>
<tr><td class="h"><a name="185"></a>185</td><td></td><td></td><td></td><td></td><td class="s">caching in all packages.</td></tr>
<tr><td class="h"><a name="186"></a>186</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="187"></a>187</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::method_changed_in($classname)</td></tr>
<tr><td class="h"><a name="188"></a>188</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="189"></a>189</td><td></td><td></td><td></td><td></td><td class="s">Invalidates the method cache of any classes dependent on the</td></tr>
<tr><td class="h"><a name="190"></a>190</td><td></td><td></td><td></td><td></td><td class="s">given class. This is not normally necessary. The only</td></tr>
<tr><td class="h"><a name="191"></a>191</td><td></td><td></td><td></td><td></td><td class="s">known case where pure perl code can confuse the method</td></tr>
<tr><td class="h"><a name="192"></a>192</td><td></td><td></td><td></td><td></td><td class="s">cache is when you manually install a new constant</td></tr>
<tr><td class="h"><a name="193"></a>193</td><td></td><td></td><td></td><td></td><td class="s">subroutine by using a readonly scalar value, like the</td></tr>
<tr><td class="h"><a name="194"></a>194</td><td></td><td></td><td></td><td></td><td class="s">internals of L<constant> do. If you find another case,</td></tr>
<tr><td class="h"><a name="195"></a>195</td><td></td><td></td><td></td><td></td><td class="s">please report it so we can either fix it or document</td></tr>
<tr><td class="h"><a name="196"></a>196</td><td></td><td></td><td></td><td></td><td class="s">the exception here.</td></tr>
<tr><td class="h"><a name="197"></a>197</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="198"></a>198</td><td></td><td></td><td></td><td></td><td class="s">=head2 mro::get_pkg_gen($classname)</td></tr>
<tr><td class="h"><a name="199"></a>199</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="200"></a>200</td><td></td><td></td><td></td><td></td><td class="s">Returns an integer which is incremented every time a</td></tr>
<tr><td class="h"><a name="201"></a>201</td><td></td><td></td><td></td><td></td><td class="s">real local method in the package C<$classname> changes,</td></tr>
<tr><td class="h"><a name="202"></a>202</td><td></td><td></td><td></td><td></td><td class="s">or the local C<@ISA> of C<$classname> is modified.</td></tr>
<tr><td class="h"><a name="203"></a>203</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="204"></a>204</td><td></td><td></td><td></td><td></td><td class="s">This is intended for authors of modules which do lots</td></tr>
<tr><td class="h"><a name="205"></a>205</td><td></td><td></td><td></td><td></td><td class="s">of class introspection, as it allows them to very quickly</td></tr>
<tr><td class="h"><a name="206"></a>206</td><td></td><td></td><td></td><td></td><td class="s">check if anything important about the local properties</td></tr>
<tr><td class="h"><a name="207"></a>207</td><td></td><td></td><td></td><td></td><td class="s">of a given class have changed since the last time they</td></tr>
<tr><td class="h"><a name="208"></a>208</td><td></td><td></td><td></td><td></td><td class="s">looked. It does not increment on method/C<@ISA></td></tr>
<tr><td class="h"><a name="209"></a>209</td><td></td><td></td><td></td><td></td><td class="s">changes in superclasses.</td></tr>
<tr><td class="h"><a name="210"></a>210</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="211"></a>211</td><td></td><td></td><td></td><td></td><td class="s">It's still up to you to seek out the actual changes,</td></tr>
<tr><td class="h"><a name="212"></a>212</td><td></td><td></td><td></td><td></td><td class="s">and there might not actually be any. Perhaps all</td></tr>
<tr><td class="h"><a name="213"></a>213</td><td></td><td></td><td></td><td></td><td class="s">of the changes since you last checked cancelled each</td></tr>
<tr><td class="h"><a name="214"></a>214</td><td></td><td></td><td></td><td></td><td class="s">other out and left the package in the state it was in</td></tr>
<tr><td class="h"><a name="215"></a>215</td><td></td><td></td><td></td><td></td><td class="s">before.</td></tr>
<tr><td class="h"><a name="216"></a>216</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="217"></a>217</td><td></td><td></td><td></td><td></td><td class="s">This integer normally starts off at a value of C<1></td></tr>
<tr><td class="h"><a name="218"></a>218</td><td></td><td></td><td></td><td></td><td class="s">when a package stash is instantiated. Calling it</td></tr>
<tr><td class="h"><a name="219"></a>219</td><td></td><td></td><td></td><td></td><td class="s">on packages whose stashes do not exist at all will</td></tr>
<tr><td class="h"><a name="220"></a>220</td><td></td><td></td><td></td><td></td><td class="s">return C<0>. If a package stash is completely</td></tr>
<tr><td class="h"><a name="221"></a>221</td><td></td><td></td><td></td><td></td><td class="s">deleted (not a normal occurence, but it can happen</td></tr>
<tr><td class="h"><a name="222"></a>222</td><td></td><td></td><td></td><td></td><td class="s">if someone does something like C<undef %PkgName::>),</td></tr>
<tr><td class="h"><a name="223"></a>223</td><td></td><td></td><td></td><td></td><td class="s">the number will be reset to either C<0> or C<1>,</td></tr>
<tr><td class="h"><a name="224"></a>224</td><td></td><td></td><td></td><td></td><td class="s">depending on how completely package was wiped out.</td></tr>
<tr><td class="h"><a name="225"></a>225</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="226"></a>226</td><td></td><td></td><td></td><td></td><td class="s">=head2 next::method</td></tr>
<tr><td class="h"><a name="227"></a>227</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="228"></a>228</td><td></td><td></td><td></td><td></td><td class="s">This is somewhat like C<SUPER>, but it uses the C3 method</td></tr>
<tr><td class="h"><a name="229"></a>229</td><td></td><td></td><td></td><td></td><td class="s">resolution order to get better consistency in multiple</td></tr>
<tr><td class="h"><a name="230"></a>230</td><td></td><td></td><td></td><td></td><td class="s">inheritance situations. Note that while inheritance in</td></tr>
<tr><td class="h"><a name="231"></a>231</td><td></td><td></td><td></td><td></td><td class="s">general follows whichever MRO is in effect for the</td></tr>
<tr><td class="h"><a name="232"></a>232</td><td></td><td></td><td></td><td></td><td class="s">given class, C<next::method> only uses the C3 MRO.</td></tr>
<tr><td class="h"><a name="233"></a>233</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="234"></a>234</td><td></td><td></td><td></td><td></td><td class="s">One generally uses it like so:</td></tr>
<tr><td class="h"><a name="235"></a>235</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="236"></a>236</td><td></td><td></td><td></td><td></td><td class="s"> sub some_method {</td></tr>
<tr><td class="h"><a name="237"></a>237</td><td></td><td></td><td></td><td></td><td class="s"> my $self = shift;</td></tr>
<tr><td class="h"><a name="238"></a>238</td><td></td><td></td><td></td><td></td><td class="s"> my $superclass_answer = $self->next::method(@_);</td></tr>
<tr><td class="h"><a name="239"></a>239</td><td></td><td></td><td></td><td></td><td class="s"> return $superclass_answer + 1;</td></tr>
<tr><td class="h"><a name="240"></a>240</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="241"></a>241</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="242"></a>242</td><td></td><td></td><td></td><td></td><td class="s">Note that you don't (re-)specify the method name.</td></tr>
<tr><td class="h"><a name="243"></a>243</td><td></td><td></td><td></td><td></td><td class="s">It forces you to always use the same method name</td></tr>
<tr><td class="h"><a name="244"></a>244</td><td></td><td></td><td></td><td></td><td class="s">as the method you started in.</td></tr>
<tr><td class="h"><a name="245"></a>245</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="246"></a>246</td><td></td><td></td><td></td><td></td><td class="s">It can be called on an object or a class, of course.</td></tr>
<tr><td class="h"><a name="247"></a>247</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="248"></a>248</td><td></td><td></td><td></td><td></td><td class="s">The way it resolves which actual method to call is:</td></tr>
<tr><td class="h"><a name="249"></a>249</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="250"></a>250</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="251"></a>251</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="252"></a>252</td><td></td><td></td><td></td><td></td><td class="s">=item 1</td></tr>
<tr><td class="h"><a name="253"></a>253</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="254"></a>254</td><td></td><td></td><td></td><td></td><td class="s">First, it determines the linearized C3 MRO of</td></tr>
<tr><td class="h"><a name="255"></a>255</td><td></td><td></td><td></td><td></td><td class="s">the object or class it is being called on.</td></tr>
<tr><td class="h"><a name="256"></a>256</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="257"></a>257</td><td></td><td></td><td></td><td></td><td class="s">=item 2</td></tr>
<tr><td class="h"><a name="258"></a>258</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="259"></a>259</td><td></td><td></td><td></td><td></td><td class="s">Then, it determines the class and method name</td></tr>
<tr><td class="h"><a name="260"></a>260</td><td></td><td></td><td></td><td></td><td class="s">of the context it was invoked from.</td></tr>
<tr><td class="h"><a name="261"></a>261</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="262"></a>262</td><td></td><td></td><td></td><td></td><td class="s">=item 3</td></tr>
<tr><td class="h"><a name="263"></a>263</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="264"></a>264</td><td></td><td></td><td></td><td></td><td class="s">Finally, it searches down the C3 MRO list until</td></tr>
<tr><td class="h"><a name="265"></a>265</td><td></td><td></td><td></td><td></td><td class="s">it reaches the contextually enclosing class, then</td></tr>
<tr><td class="h"><a name="266"></a>266</td><td></td><td></td><td></td><td></td><td class="s">searches further down the MRO list for the next</td></tr>
<tr><td class="h"><a name="267"></a>267</td><td></td><td></td><td></td><td></td><td class="s">method with the same name as the contextually</td></tr>
<tr><td class="h"><a name="268"></a>268</td><td></td><td></td><td></td><td></td><td class="s">enclosing method.</td></tr>
<tr><td class="h"><a name="269"></a>269</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="270"></a>270</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="271"></a>271</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="272"></a>272</td><td></td><td></td><td></td><td></td><td class="s">Failure to find a next method will result in an</td></tr>
<tr><td class="h"><a name="273"></a>273</td><td></td><td></td><td></td><td></td><td class="s">exception being thrown (see below for alternatives).</td></tr>
<tr><td class="h"><a name="274"></a>274</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="275"></a>275</td><td></td><td></td><td></td><td></td><td class="s">This is substantially different than the behavior</td></tr>
<tr><td class="h"><a name="276"></a>276</td><td></td><td></td><td></td><td></td><td class="s">of C<SUPER> under complex multiple inheritance.</td></tr>
<tr><td class="h"><a name="277"></a>277</td><td></td><td></td><td></td><td></td><td class="s">(This becomes obvious when one realizes that the</td></tr>
<tr><td class="h"><a name="278"></a>278</td><td></td><td></td><td></td><td></td><td class="s">common superclasses in the C3 linearizations of</td></tr>
<tr><td class="h"><a name="279"></a>279</td><td></td><td></td><td></td><td></td><td class="s">a given class and one of its parents will not</td></tr>
<tr><td class="h"><a name="280"></a>280</td><td></td><td></td><td></td><td></td><td class="s">always be ordered the same for both.)</td></tr>
<tr><td class="h"><a name="281"></a>281</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="282"></a>282</td><td></td><td></td><td></td><td></td><td class="s">B<Caveat>: Calling C<next::method> from methods defined outside the class:</td></tr>
<tr><td class="h"><a name="283"></a>283</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="284"></a>284</td><td></td><td></td><td></td><td></td><td class="s">There is an edge case when using C<next::method> from within a subroutine</td></tr>
<tr><td class="h"><a name="285"></a>285</td><td></td><td></td><td></td><td></td><td class="s">which was created in a different module than the one it is called from. It</td></tr>
<tr><td class="h"><a name="286"></a>286</td><td></td><td></td><td></td><td></td><td class="s">sounds complicated, but it really isn't. Here is an example which will not</td></tr>
<tr><td class="h"><a name="287"></a>287</td><td></td><td></td><td></td><td></td><td class="s">work correctly:</td></tr>
<tr><td class="h"><a name="288"></a>288</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="289"></a>289</td><td></td><td></td><td></td><td></td><td class="s"> *Foo::foo = sub { (shift)->next::method(@_) };</td></tr>
<tr><td class="h"><a name="290"></a>290</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="291"></a>291</td><td></td><td></td><td></td><td></td><td class="s">The problem exists because the anonymous subroutine being assigned to the</td></tr>
<tr><td class="h"><a name="292"></a>292</td><td></td><td></td><td></td><td></td><td class="s">C<*Foo::foo> glob will show up in the call stack as being called</td></tr>
<tr><td class="h"><a name="293"></a>293</td><td></td><td></td><td></td><td></td><td class="s">C<__ANON__> and not C<foo> as you might expect. Since C<next::method> uses</td></tr>
<tr><td class="h"><a name="294"></a>294</td><td></td><td></td><td></td><td></td><td class="s">C<caller> to find the name of the method it was called in, it will fail in</td></tr>
<tr><td class="h"><a name="295"></a>295</td><td></td><td></td><td></td><td></td><td class="s">this case. </td></tr>
<tr><td class="h"><a name="296"></a>296</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="297"></a>297</td><td></td><td></td><td></td><td></td><td class="s">But fear not, there's a simple solution. The module C<Sub::Name> will</td></tr>
<tr><td class="h"><a name="298"></a>298</td><td></td><td></td><td></td><td></td><td class="s">reach into the perl internals and assign a name to an anonymous subroutine</td></tr>
<tr><td class="h"><a name="299"></a>299</td><td></td><td></td><td></td><td></td><td class="s">for you. Simply do this:</td></tr>
<tr><td class="h"><a name="300"></a>300</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="301"></a>301</td><td></td><td></td><td></td><td></td><td class="s"> use Sub::Name 'subname';</td></tr>
<tr><td class="h"><a name="302"></a>302</td><td></td><td></td><td></td><td></td><td class="s"> *Foo::foo = subname 'Foo::foo' => sub { (shift)->next::method(@_) };</td></tr>
<tr><td class="h"><a name="303"></a>303</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="304"></a>304</td><td></td><td></td><td></td><td></td><td class="s">and things will Just Work.</td></tr>
<tr><td class="h"><a name="305"></a>305</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="306"></a>306</td><td></td><td></td><td></td><td></td><td class="s">=head2 next::can</td></tr>
<tr><td class="h"><a name="307"></a>307</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="308"></a>308</td><td></td><td></td><td></td><td></td><td class="s">This is similar to C<next::method>, but just returns either a code</td></tr>
<tr><td class="h"><a name="309"></a>309</td><td></td><td></td><td></td><td></td><td class="s">reference or C<undef> to indicate that no further methods of this name</td></tr>
<tr><td class="h"><a name="310"></a>310</td><td></td><td></td><td></td><td></td><td class="s">exist.</td></tr>
<tr><td class="h"><a name="311"></a>311</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="312"></a>312</td><td></td><td></td><td></td><td></td><td class="s">=head2 maybe::next::method</td></tr>
<tr><td class="h"><a name="313"></a>313</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="314"></a>314</td><td></td><td></td><td></td><td></td><td class="s">In simple cases, it is equivalent to:</td></tr>
<tr><td class="h"><a name="315"></a>315</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="316"></a>316</td><td></td><td></td><td></td><td></td><td class="s"> $self->next::method(@_) if $self->next::can;</td></tr>
<tr><td class="h"><a name="317"></a>317</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="318"></a>318</td><td></td><td></td><td></td><td></td><td class="s">But there are some cases where only this solution</td></tr>
<tr><td class="h"><a name="319"></a>319</td><td></td><td></td><td></td><td></td><td class="s">works (like C<goto &maybe::next::method>);</td></tr>
<tr><td class="h"><a name="320"></a>320</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="321"></a>321</td><td></td><td></td><td></td><td></td><td class="s">=head1 SEE ALSO</td></tr>
<tr><td class="h"><a name="322"></a>322</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="323"></a>323</td><td></td><td></td><td></td><td></td><td class="s">=head2 The original Dylan paper</td></tr>
<tr><td class="h"><a name="324"></a>324</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="325"></a>325</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="326"></a>326</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="327"></a>327</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://www.webcom.com/haahr/dylan/linearization-oopsla96.html></td></tr>
<tr><td class="h"><a name="328"></a>328</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="329"></a>329</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="330"></a>330</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="331"></a>331</td><td></td><td></td><td></td><td></td><td class="s">=head2 The prototype Perl 6 Object Model uses C3</td></tr>
<tr><td class="h"><a name="332"></a>332</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="333"></a>333</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="334"></a>334</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="335"></a>335</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel/></td></tr>
<tr><td class="h"><a name="336"></a>336</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="337"></a>337</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="338"></a>338</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="339"></a>339</td><td></td><td></td><td></td><td></td><td class="s">=head2 Parrot now uses C3</td></tr>
<tr><td class="h"><a name="340"></a>340</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="341"></a>341</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="342"></a>342</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="343"></a>343</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://aspn.activestate.com/ASPN/Mail/Message/perl6-internals/2746631></td></tr>
<tr><td class="h"><a name="344"></a>344</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="345"></a>345</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://use.perl.org/~autrijus/journal/25768></td></tr>
<tr><td class="h"><a name="346"></a>346</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="347"></a>347</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="348"></a>348</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="349"></a>349</td><td></td><td></td><td></td><td></td><td class="s">=head2 Python 2.3 MRO related links</td></tr>
<tr><td class="h"><a name="350"></a>350</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="351"></a>351</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="352"></a>352</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="353"></a>353</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://www.python.org/2.3/mro.html></td></tr>
<tr><td class="h"><a name="354"></a>354</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="355"></a>355</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://www.python.org/2.2.2/descrintro.html#mro></td></tr>
<tr><td class="h"><a name="356"></a>356</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="357"></a>357</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="358"></a>358</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="359"></a>359</td><td></td><td></td><td></td><td></td><td class="s">=head2 C3 for TinyCLOS</td></tr>
<tr><td class="h"><a name="360"></a>360</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="361"></a>361</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="362"></a>362</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="363"></a>363</td><td></td><td></td><td></td><td></td><td class="s">=item L<http://www.call-with-current-continuation.org/eggs/c3.html></td></tr>
<tr><td class="h"><a name="364"></a>364</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="365"></a>365</td><td></td><td></td><td></td><td></td><td class="s">=back </td></tr>
<tr><td class="h"><a name="366"></a>366</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="367"></a>367</td><td></td><td></td><td></td><td></td><td class="s">=head2 Class::C3</td></tr>
<tr><td class="h"><a name="368"></a>368</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="369"></a>369</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="370"></a>370</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="371"></a>371</td><td></td><td></td><td></td><td></td><td class="s">=item L<Class::C3></td></tr>
<tr><td class="h"><a name="372"></a>372</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="373"></a>373</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="374"></a>374</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="375"></a>375</td><td></td><td></td><td></td><td></td><td class="s">=head1 AUTHOR</td></tr>
<tr><td class="h"><a name="376"></a>376</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="377"></a>377</td><td></td><td></td><td></td><td></td><td class="s">Brandon L. Black, E<lt>blblack@gmail.comE<gt></td></tr>
<tr><td class="h"><a name="378"></a>378</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="379"></a>379</td><td></td><td></td><td></td><td></td><td class="s">Based on Stevan Little's L<Class::C3></td></tr>
<tr><td class="h"><a name="380"></a>380</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="381"></a>381</td><td></td><td></td><td></td><td></td><td class="s">=cut</td></tr>
<tr><td class="h"><a name="mro__get_linear_isa"></a></td><td></td><td></td><td></td><td></td><td class="s"><div class="calls"><div class="calls_in"># spent 368µs within mro::get_linear_isa which was called 218 times, avg 2µs/call:
# 217 times (366µs+0s) by Class::MOP::Class::linearized_isa at <a href="Class-MOP-Class-pm-sub.html#609">line 609 of Class/MOP/Class.pm</a>, avg 2µs/call
# once (2µs+0s) by Moose::init_meta at <a href="Moose-pm-sub.html#173">line 173 of Moose.pm</a></div></div>sub mro::get_linear_isa; # xsub<br /> </td></tr>
<tr><td class="h"><a name="mro__method_changed_in"></a></td><td></td><td></td><td></td><td></td><td class="s"><div class="calls"><div class="calls_in"># spent 117µs within mro::method_changed_in which was called 86 times, avg 1µs/call:
# 86 times (117µs+0s) by constant::import at <a href="constant-pm-sub.html#113">line 113 of constant.pm</a>, avg 1µs/call</div></div>sub mro::method_changed_in; # xsub<br /> </td></tr>
</tbody></table></div>
<script type="text/javascript"> $(document).ready(function() {
$("#subs_table").tablesorter({
sortList: [[3,1]],
headers: {
3: { sorter: 'fmt_time' },
4: { sorter: 'fmt_time' }
}
});
} ); </script>
<div class="footer">Report produced by the
<a href="http://search.cpan.org/dist/Devel-NYTProf/">NYTProf 3.11</a>
Perl profiler, developed by
<a href="http://www.linkedin.com/in/timbunce">Tim Bunce</a> and
<a href="http://code.nytimes.com">Adam Kaplan</a>.
</div>
<br /><br /><br /><br /><br /><br /><br /><br /><br /><br />
</body></html>