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<span class="siteTitle">NYTProf Performance Profile</span>
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<span class="siteSubtitle">Run on Tue May 4 15:25:55 2010<br />Reported on Tue May 4 15:26:08 2010</span>
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<table>
<tr>
<td class="h" align="right">File</td>
<td align="left">/usr/local/lib/perl5/site_perl/5.10.1/Try/Tiny.pm</td>
</tr>
<tr>
<td class="h" align="right">Statements Executed</td>
<td align="left">6440</td>
</tr>
<tr>
<td class="h" align="right">Statement Execution Time</td>
<td align="left">5.17ms</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="c0">292</td><td class="c0">3</td><td class="c0">3</td><td class="c0"><span title="0.3%">3.22ms</span></td><td class="c0"><span title="3.7%">40.5ms</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::try</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#25">try</a></span></td></tr>
<tr><td class="c0">292</td><td class="c0">3</td><td class="c0">3</td><td class="c0"><span title="0.1%">858µs</span></td><td class="c0"><span title="0.1%">858µs</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::catch</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#112">catch</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%">27µs</span></td><td class="c3"><span title="0.0%">37µs</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::BEGIN@3</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#3">BEGIN@3</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%">14µs</span></td><td class="c3"><span title="0.0%">14µs</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::BEGIN@8</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#8">BEGIN@8</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%">10µs</span></td><td class="c3"><span title="0.0%">89µs</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::BEGIN@6</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#6">BEGIN@6</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%">9µs</span></td><td class="c3"><span title="0.0%">62µs</span></td><td class="sub_name"><span style="display: none;">Try::Tiny::::BEGIN@46</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#46">BEGIN@46</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;">Try::Tiny::ScopeGuard::::DESTROY</span>Try::Tiny::ScopeGuard::<a href="Try-Tiny-pm-block.html#130">DESTROY</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;">Try::Tiny::::finally</span> Try::Tiny::<a href="Try-Tiny-pm-block.html#121">finally</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-site_perl-5-10-1-Try-Tiny-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">package Try::Tiny;</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 class="c3">3</td><td class="c3"><span title="Avg 16µs">47µs</span></td><td class="c3">2</td><td class="c3">47µs</td><td class="s"><div class="calls"><div class="calls_in"># spent 37µs (27+10) within Try::Tiny::BEGIN@3 which was called
# once (27µs+10µs) by Class::MOP::BEGIN@13 at <a href="Try-Tiny-pm-block.html#3">line 3</a></div></div>use strict;<div class="calls"><div class="calls_out"># spent 37µs making 1 call to <a href="Try-Tiny-pm-block.html#3">Try::Tiny::BEGIN@3</a>
# spent 10µs making 1 call to <a href="strict-pm-block.html#34">strict::import</a></div></div></td></tr>
<tr><td class="h"><a name="4"></a>4</td><td></td><td></td><td></td><td></td><td class="s">#use warnings;</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 class="c3">3</td><td class="c3"><span title="Avg 17µs">50µs</span></td><td class="c3">2</td><td class="c2">168µs</td><td class="s"><div class="calls"><div class="calls_in"># spent 89µs (10+79) within Try::Tiny::BEGIN@6 which was called
# once (10µs+79µs) by Class::MOP::BEGIN@13 at <a href="Try-Tiny-pm-block.html#6">line 6</a></div></div>use vars qw(@EXPORT @EXPORT_OK $VERSION @ISA);<div class="calls"><div class="calls_out"># spent 89µs making 1 call to <a href="Try-Tiny-pm-block.html#6">Try::Tiny::BEGIN@6</a>
# spent 79µs making 1 call to <a href="vars-pm-block.html#10">vars::import</a></div></div></td></tr>
<tr><td class="h"><a name="7"></a>7</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="8"></a>8</td><td></td><td></td><td></td><td></td><td class="s"><div class="calls"><div class="calls_in"># spent 14µs within Try::Tiny::BEGIN@8 which was called
# once (14µs+0s) by Class::MOP::BEGIN@13 at <a href="Try-Tiny-pm-block.html#11">line 11</a></div></div>BEGIN {</td></tr>
<tr><td class="h"><a name="9"></a>9</td><td class="c3">2</td><td class="c3"><span title="Avg 14µs">27µs</span></td><td></td><td></td><td class="s"> require Exporter;</td></tr>
<tr><td class="h"><a name="10"></a>10</td><td></td><td></td><td></td><td></td><td class="s"> @ISA = qw(Exporter);</td></tr>
<tr><td class="h"><a name="11"></a>11</td><td class="c3">1</td><td class="c3"><span title="Avg 120µs">120µs</span></td><td class="c3">1</td><td class="c3">14µs</td><td class="s">}<div class="calls"><div class="calls_out"># spent 14µs making 1 call to <a href="Try-Tiny-pm-block.html#8">Try::Tiny::BEGIN@8</a></div></div></td></tr>
<tr><td class="h"><a name="12"></a>12</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="13"></a>13</td><td class="c3">1</td><td class="c3"><span title="Avg 3µs">3µs</span></td><td></td><td></td><td class="s">$VERSION = "0.04";</td></tr>
<tr><td class="h"><a name="14"></a>14</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="15"></a>15</td><td class="c3">1</td><td class="c3"><span title="Avg 63µs">63µs</span></td><td></td><td></td><td class="s">$VERSION = eval $VERSION;</td></tr>
<tr><td class="h"><a name="16"></a>16</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="17"></a>17</td><td class="c3">1</td><td class="c3"><span title="Avg 4µs">4µs</span></td><td></td><td></td><td class="s">@EXPORT = @EXPORT_OK = qw(try catch finally);</td></tr>
<tr><td class="h"><a name="18"></a>18</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="19"></a>19</td><td class="c3">1</td><td class="c3"><span title="Avg 2µs">2µs</span></td><td></td><td></td><td class="s">$Carp::Internal{+__PACKAGE__}++;</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"># Need to prototype as @ not $$ because of the way Perl evaluates the prototype.</td></tr>
<tr><td class="h"><a name="22"></a>22</td><td></td><td></td><td></td><td></td><td class="s"># Keeping it at $$ means you only ever get 1 sub because we need to eval in a list</td></tr>
<tr><td class="h"><a name="23"></a>23</td><td></td><td></td><td></td><td></td><td class="s"># context & not a scalar one</td></tr>
<tr><td class="h"><a name="24"></a>24</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="25"></a>25</td><td></td><td></td><td></td><td></td><td class="s"><div class="calls"><div class="calls_in"># spent 40.5ms (3.22+37.3) within Try::Tiny::try which was called 292 times, avg 139µs/call:
# 172 times (1.91ms+11.3ms) by Class::MOP::Attribute::_process_accessors at <a href="Class-MOP-Attribute-pm-block.html#343">line 343 of Class/MOP/Attribute.pm</a>, avg 77µs/call
# 119 times (1.30ms+25.2ms) by Class::MOP::Class::_post_add_attribute at <a href="Class-MOP-Class-pm-block.html#519">line 519 of Class/MOP/Class.pm</a>, avg 223µs/call
# once (16µs+778µs) by Class::MOP::load_first_existing_class at <a href="Class-MOP-pm-block.html#110">line 110 of Class/MOP.pm</a></div></div>sub try (&;@) {</td></tr>
<tr><td class="h"><a name="26"></a>26</td><td class="c0">2628</td><td class="c0"><span title="Avg 242ns">636µs</span></td><td></td><td></td><td class="s"> my ( $try, @code_refs ) = @_;</td></tr>
<tr><td class="h"><a name="27"></a>27</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="28"></a>28</td><td></td><td></td><td></td><td></td><td class="s"> # we need to save this here, the eval block will be in scalar context due</td></tr>
<tr><td class="h"><a name="29"></a>29</td><td></td><td></td><td></td><td></td><td class="s"> # to $failed</td></tr>
<tr><td class="h"><a name="30"></a>30</td><td></td><td></td><td></td><td></td><td class="s"> my $wantarray = wantarray;</td></tr>
<tr><td class="h"><a name="31"></a>31</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="32"></a>32</td><td></td><td></td><td></td><td></td><td class="s"> my ( $catch, $finally );</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"> # find labeled blocks in the argument list.</td></tr>
<tr><td class="h"><a name="35"></a>35</td><td></td><td></td><td></td><td></td><td class="s"> # catch and finally tag the blocks by blessing a scalar reference to them.</td></tr>
<tr><td class="h"><a name="36"></a>36</td><td></td><td></td><td></td><td></td><td class="s"> foreach my $code_ref (@code_refs) {</td></tr>
<tr><td class="h"><a name="37"></a>37</td><td class="c0">876</td><td class="c0"><span title="Avg 428ns">375µs</span></td><td></td><td></td><td class="s"> next unless $code_ref;</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"> my $ref = ref($code_ref);</td></tr>
<tr><td class="h"><a name="40"></a>40</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="41"></a>41</td><td></td><td></td><td></td><td></td><td class="s"> if ( $ref eq 'Try::Tiny::Catch' ) {</td></tr>
<tr><td class="h"><a name="42"></a>42</td><td></td><td></td><td></td><td></td><td class="s"> $catch = ${$code_ref};</td></tr>
<tr><td class="h"><a name="43"></a>43</td><td></td><td></td><td></td><td></td><td class="s"> } elsif ( $ref eq 'Try::Tiny::Finally' ) {</td></tr>
<tr><td class="h"><a name="44"></a>44</td><td></td><td></td><td></td><td></td><td class="s"> $finally = ${$code_ref};</td></tr>
<tr><td class="h"><a name="45"></a>45</td><td></td><td></td><td></td><td></td><td class="s"> } else {</td></tr>
<tr><td class="h"><a name="46"></a>46</td><td class="c3">3</td><td class="c0"><span title="Avg 434µs">1.30ms</span></td><td class="c3">2</td><td class="c3">116µs</td><td class="s"><div class="calls"><div class="calls_in"># spent 62µs (9+53) within Try::Tiny::BEGIN@46 which was called
# once (9µs+53µs) by Class::MOP::BEGIN@13 at <a href="Try-Tiny-pm-block.html#46">line 46</a></div></div> use Carp;<div class="calls"><div class="calls_out"> # spent 62µs making 1 call to <a href="Try-Tiny-pm-block.html#46">Try::Tiny::BEGIN@46</a>
# spent 53µs making 1 call to <a href="Exporter-pm-block.html#31">Exporter::import</a></div></div></td></tr>
<tr><td class="h"><a name="47"></a>47</td><td></td><td></td><td></td><td></td><td class="s"> confess("Unknown code ref type given '${ref}'. Check your usage & try again");</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"> }</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"> # save the value of $@ so we can set $@ back to it in the beginning of the eval</td></tr>
<tr><td class="h"><a name="52"></a>52</td><td></td><td></td><td></td><td></td><td class="s"> my $prev_error = $@;</td></tr>
<tr><td class="h"><a name="53"></a>53</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="54"></a>54</td><td></td><td></td><td></td><td></td><td class="s"> my ( @ret, $error, $failed );</td></tr>
<tr><td class="h"><a name="55"></a>55</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="56"></a>56</td><td></td><td></td><td></td><td></td><td class="s"> # FIXME consider using local $SIG{__DIE__} to accumulate all errors. It's</td></tr>
<tr><td class="h"><a name="57"></a>57</td><td></td><td></td><td></td><td></td><td class="s"> # not perfect, but we could provide a list of additional errors for</td></tr>
<tr><td class="h"><a name="58"></a>58</td><td></td><td></td><td></td><td></td><td class="s"> # $catch->();</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"> {</td></tr>
<tr><td class="h"><a name="61"></a>61</td><td></td><td></td><td></td><td></td><td class="s"> # localize $@ to prevent clobbering of previous value by a successful</td></tr>
<tr><td class="h"><a name="62"></a>62</td><td></td><td></td><td></td><td></td><td class="s"> # eval.</td></tr>
<tr><td class="h"><a name="63"></a>63</td><td class="c0">876</td><td class="c1"><span title="Avg 373ns">327µs</span></td><td></td><td></td><td class="s"> local $@;</td></tr>
<tr><td class="h"><a name="64"></a>64</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="65"></a>65</td><td></td><td></td><td></td><td></td><td class="s"> # failed will be true if the eval dies, because 1 will not be returned</td></tr>
<tr><td class="h"><a name="66"></a>66</td><td></td><td></td><td></td><td></td><td class="s"> # from the eval body</td></tr>
<tr><td class="h"><a name="67"></a>67</td><td class="c0">876</td><td class="c1"><span title="Avg 278ns">244µs</span></td><td></td><td></td><td class="s"> $failed = not eval {</td></tr>
<tr><td class="h"><a name="68"></a>68</td><td></td><td></td><td></td><td></td><td class="s"> $@ = $prev_error;</td></tr>
<tr><td class="h"><a name="69"></a>69</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="70"></a>70</td><td></td><td></td><td></td><td></td><td class="s"> # evaluate the try block in the correct context</td></tr>
<tr><td class="h"><a name="71"></a>71</td><td class="c0">291</td><td class="c1"><span title="Avg 1µs">317µs</span></td><td class="c3">1</td><td class="c0">778µs</td><td class="s"> if ( $wantarray ) {<div class="calls"><div class="calls_out"> # spent 778µs making 1 call to <a href="Class-MOP-pm-block.html#99">Class::MOP::__ANON__[Class/MOP.pm:103]</a></div></div></td></tr>
<tr><td class="h"><a name="72"></a>72</td><td></td><td></td><td></td><td></td><td class="s"> @ret = $try->();</td></tr>
<tr><td class="h"><a name="73"></a>73</td><td></td><td></td><td></td><td></td><td class="s"> } elsif ( defined $wantarray ) {</td></tr>
<tr><td class="h"><a name="74"></a>74</td><td></td><td></td><td></td><td></td><td class="s"> $ret[0] = $try->();</td></tr>
<tr><td class="h"><a name="75"></a>75</td><td></td><td></td><td></td><td></td><td class="s"> } else {</td></tr>
<tr><td class="h"><a name="76"></a>76</td><td></td><td></td><td></td><td></td><td class="s"> $try->();<div class="calls"><div class="calls_out"> # spent 25.2ms making 119 calls to <a href="Class-MOP-Class-pm-block.html#512">Class::MOP::Class::__ANON__[Class/MOP/Class.pm:515]</a>, avg 212µs/call
# spent 20.5ms making 172 calls to <a href="Class-MOP-Attribute-pm-block.html#322">Class::MOP::Attribute::__ANON__[Class/MOP/Attribute.pm:340]</a>, avg 119µs/call</div></div></td></tr>
<tr><td class="h"><a name="77"></a>77</td><td></td><td></td><td></td><td></td><td class="s"> };</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"> return 1; # properly set $fail to false</td></tr>
<tr><td class="h"><a name="80"></a>80</td><td></td><td></td><td></td><td></td><td class="s"> };</td></tr>
<tr><td class="h"><a name="81"></a>81</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="82"></a>82</td><td></td><td></td><td></td><td></td><td class="s"> # copy $@ to $error; when we leave this scope, local $@ will revert $@</td></tr>
<tr><td class="h"><a name="83"></a>83</td><td></td><td></td><td></td><td></td><td class="s"> # back to its previous value</td></tr>
<tr><td class="h"><a name="84"></a>84</td><td></td><td></td><td></td><td></td><td class="s"> $error = $@;</td></tr>
<tr><td class="h"><a name="85"></a>85</td><td></td><td></td><td></td><td></td><td class="s"> }</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"> # set up a scope guard to invoke the finally block at the end</td></tr>
<tr><td class="h"><a name="88"></a>88</td><td></td><td></td><td></td><td></td><td class="s"> my $guard = $finally && bless \$finally, "Try::Tiny::ScopeGuard";</td></tr>
<tr><td class="h"><a name="89"></a>89</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="90"></a>90</td><td></td><td></td><td></td><td></td><td class="s"> # at this point $failed contains a true value if the eval died, even if some</td></tr>
<tr><td class="h"><a name="91"></a>91</td><td></td><td></td><td></td><td></td><td class="s"> # destructor overwrote $@ as the eval was unwinding.</td></tr>
<tr><td class="h"><a name="92"></a>92</td><td class="c0">292</td><td class="c0"><span title="Avg 2µs">603µs</span></td><td></td><td></td><td class="s"> if ( $failed ) {</td></tr>
<tr><td class="h"><a name="93"></a>93</td><td></td><td></td><td></td><td></td><td class="s"> # if we got an error, invoke the catch block.</td></tr>
<tr><td class="h"><a name="94"></a>94</td><td></td><td></td><td></td><td></td><td class="s"> if ( $catch ) {</td></tr>
<tr><td class="h"><a name="95"></a>95</td><td></td><td></td><td></td><td></td><td class="s"> # This works like given($error), but is backwards compatible and</td></tr>
<tr><td class="h"><a name="96"></a>96</td><td></td><td></td><td></td><td></td><td class="s"> # sets $_ in the dynamic scope for the body of C<$catch></td></tr>
<tr><td class="h"><a name="97"></a>97</td><td></td><td></td><td></td><td></td><td class="s"> for ($error) {</td></tr>
<tr><td class="h"><a name="98"></a>98</td><td></td><td></td><td></td><td></td><td class="s"> return $catch->($error);</td></tr>
<tr><td class="h"><a name="99"></a>99</td><td></td><td></td><td></td><td></td><td class="s"> }</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"> # in case when() was used without an explicit return, the C<for></td></tr>
<tr><td class="h"><a name="102"></a>102</td><td></td><td></td><td></td><td></td><td class="s"> # loop will be aborted and there's no useful return value</td></tr>
<tr><td class="h"><a name="103"></a>103</td><td></td><td></td><td></td><td></td><td class="s"> }</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"> return;</td></tr>
<tr><td class="h"><a name="106"></a>106</td><td></td><td></td><td></td><td></td><td class="s"> } else {</td></tr>
<tr><td class="h"><a name="107"></a>107</td><td></td><td></td><td></td><td></td><td class="s"> # no failure, $@ is back to what it was, everything is fine</td></tr>
<tr><td class="h"><a name="108"></a>108</td><td></td><td></td><td></td><td></td><td class="s"> return $wantarray ? @ret : $ret[0];</td></tr>
<tr><td class="h"><a name="109"></a>109</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="110"></a>110</td><td></td><td></td><td></td><td></td><td class="s">}</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"><div class="calls"><div class="calls_in"># spent 858µs within Try::Tiny::catch which was called 292 times, avg 3µs/call:
# 172 times (487µs+0s) by Class::MOP::Attribute::_process_accessors at <a href="Class-MOP-Attribute-pm-block.html#343">line 343 of Class/MOP/Attribute.pm</a>, avg 3µs/call
# 119 times (367µs+0s) by Class::MOP::Class::_post_add_attribute at <a href="Class-MOP-Class-pm-block.html#519">line 519 of Class/MOP/Class.pm</a>, avg 3µs/call
# once (4µs+0s) by Class::MOP::load_first_existing_class at <a href="Class-MOP-pm-block.html#110">line 110 of Class/MOP.pm</a></div></div>sub catch (&;@) {</td></tr>
<tr><td class="h"><a name="113"></a>113</td><td class="c0">584</td><td class="c0"><span title="Avg 2µs">1.03ms</span></td><td></td><td></td><td class="s"> my ( $block, @rest ) = @_;</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"> return (</td></tr>
<tr><td class="h"><a name="116"></a>116</td><td></td><td></td><td></td><td></td><td class="s"> bless(\$block, 'Try::Tiny::Catch'),</td></tr>
<tr><td class="h"><a name="117"></a>117</td><td></td><td></td><td></td><td></td><td class="s"> @rest,</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">}</td></tr>
<tr><td class="h"><a name="120"></a>120</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="121"></a>121</td><td></td><td></td><td></td><td></td><td class="s">sub finally (&;@) {</td></tr>
<tr><td class="h"><a name="122"></a>122</td><td></td><td></td><td></td><td></td><td class="s"> my ( $block, @rest ) = @_;</td></tr>
<tr><td class="h"><a name="123"></a>123</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="124"></a>124</td><td></td><td></td><td></td><td></td><td class="s"> return (</td></tr>
<tr><td class="h"><a name="125"></a>125</td><td></td><td></td><td></td><td></td><td class="s"> bless(\$block, 'Try::Tiny::Finally'),</td></tr>
<tr><td class="h"><a name="126"></a>126</td><td></td><td></td><td></td><td></td><td class="s"> @rest,</td></tr>
<tr><td class="h"><a name="127"></a>127</td><td></td><td></td><td></td><td></td><td class="s"> );</td></tr>
<tr><td class="h"><a name="128"></a>128</td><td></td><td></td><td></td><td></td><td class="s">}</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">sub Try::Tiny::ScopeGuard::DESTROY {</td></tr>
<tr><td class="h"><a name="131"></a>131</td><td></td><td></td><td></td><td></td><td class="s"> my $self = shift;</td></tr>
<tr><td class="h"><a name="132"></a>132</td><td></td><td></td><td></td><td></td><td class="s"> $$self->();</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"></td></tr>
<tr><td class="h"><a name="135"></a>135</td><td class="c3">1</td><td class="c3"><span title="Avg 14µs">14µs</span></td><td></td><td></td><td class="s">__PACKAGE__</td></tr>
<tr><td class="h"><a name="136"></a>136</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="137"></a>137</td><td></td><td></td><td></td><td></td><td class="s">__END__</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">=pod</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">=head1 NAME</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">Try::Tiny - minimal try/catch with proper localization of $@</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">=head1 SYNOPSIS</td></tr>
<tr><td class="h"><a name="146"></a>146</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="147"></a>147</td><td></td><td></td><td></td><td></td><td class="s"> # handle errors with a catch handler</td></tr>
<tr><td class="h"><a name="148"></a>148</td><td></td><td></td><td></td><td></td><td class="s"> try {</td></tr>
<tr><td class="h"><a name="149"></a>149</td><td></td><td></td><td></td><td></td><td class="s"> die "foo";</td></tr>
<tr><td class="h"><a name="150"></a>150</td><td></td><td></td><td></td><td></td><td class="s"> } catch {</td></tr>
<tr><td class="h"><a name="151"></a>151</td><td></td><td></td><td></td><td></td><td class="s"> warn "caught error: $_";</td></tr>
<tr><td class="h"><a name="152"></a>152</td><td></td><td></td><td></td><td></td><td class="s"> };</td></tr>
<tr><td class="h"><a name="153"></a>153</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="154"></a>154</td><td></td><td></td><td></td><td></td><td class="s"> # just silence errors</td></tr>
<tr><td class="h"><a name="155"></a>155</td><td></td><td></td><td></td><td></td><td class="s"> try {</td></tr>
<tr><td class="h"><a name="156"></a>156</td><td></td><td></td><td></td><td></td><td class="s"> die "foo";</td></tr>
<tr><td class="h"><a name="157"></a>157</td><td></td><td></td><td></td><td></td><td class="s"> };</td></tr>
<tr><td class="h"><a name="158"></a>158</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="159"></a>159</td><td></td><td></td><td></td><td></td><td class="s">=head1 DESCRIPTION</td></tr>
<tr><td class="h"><a name="160"></a>160</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="161"></a>161</td><td></td><td></td><td></td><td></td><td class="s">This module provides bare bones C<try>/C<catch>/C<finally> statements that are designed to</td></tr>
<tr><td class="h"><a name="162"></a>162</td><td></td><td></td><td></td><td></td><td class="s">minimize common mistakes with eval blocks, and NOTHING else.</td></tr>
<tr><td class="h"><a name="163"></a>163</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="164"></a>164</td><td></td><td></td><td></td><td></td><td class="s">This is unlike L<TryCatch> which provides a nice syntax and avoids adding</td></tr>
<tr><td class="h"><a name="165"></a>165</td><td></td><td></td><td></td><td></td><td class="s">another call stack layer, and supports calling C<return> from the try block to</td></tr>
<tr><td class="h"><a name="166"></a>166</td><td></td><td></td><td></td><td></td><td class="s">return from the parent subroutine. These extra features come at a cost of a few</td></tr>
<tr><td class="h"><a name="167"></a>167</td><td></td><td></td><td></td><td></td><td class="s">dependencies, namely L<Devel::Declare> and L<Scope::Upper> which are</td></tr>
<tr><td class="h"><a name="168"></a>168</td><td></td><td></td><td></td><td></td><td class="s">occasionally problematic, and the additional catch filtering uses L<Moose></td></tr>
<tr><td class="h"><a name="169"></a>169</td><td></td><td></td><td></td><td></td><td class="s">type constraints which may not be desirable either.</td></tr>
<tr><td class="h"><a name="170"></a>170</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="171"></a>171</td><td></td><td></td><td></td><td></td><td class="s">The main focus of this module is to provide simple and reliable error handling</td></tr>
<tr><td class="h"><a name="172"></a>172</td><td></td><td></td><td></td><td></td><td class="s">for those having a hard time installing L<TryCatch>, but who still want to</td></tr>
<tr><td class="h"><a name="173"></a>173</td><td></td><td></td><td></td><td></td><td class="s">write correct C<eval> blocks without 5 lines of boilerplate each time.</td></tr>
<tr><td class="h"><a name="174"></a>174</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="175"></a>175</td><td></td><td></td><td></td><td></td><td class="s">It's designed to work as correctly as possible in light of the various</td></tr>
<tr><td class="h"><a name="176"></a>176</td><td></td><td></td><td></td><td></td><td class="s">pathological edge cases (see L<BACKGROUND>) and to be compatible with any style</td></tr>
<tr><td class="h"><a name="177"></a>177</td><td></td><td></td><td></td><td></td><td class="s">of error values (simple strings, references, objects, overloaded objects, etc).</td></tr>
<tr><td class="h"><a name="178"></a>178</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="179"></a>179</td><td></td><td></td><td></td><td></td><td class="s">If the try block dies, it returns the value of the last statement executed in</td></tr>
<tr><td class="h"><a name="180"></a>180</td><td></td><td></td><td></td><td></td><td class="s">the catch block, if there is one. Otherwise, it returns C<undef> in scalar</td></tr>
<tr><td class="h"><a name="181"></a>181</td><td></td><td></td><td></td><td></td><td class="s">context or the empty list in list context. The following two examples both</td></tr>
<tr><td class="h"><a name="182"></a>182</td><td></td><td></td><td></td><td></td><td class="s">assign C<"bar"> to C<$x>.</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"> my $x = try { die "foo" } catch { "bar" };</td></tr>
<tr><td class="h"><a name="185"></a>185</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="186"></a>186</td><td></td><td></td><td></td><td></td><td class="s"> my $x = eval { die "foo" } || "bar";</td></tr>
<tr><td class="h"><a name="187"></a>187</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="188"></a>188</td><td></td><td></td><td></td><td></td><td class="s">You can add finally blocks making the following true.</td></tr>
<tr><td class="h"><a name="189"></a>189</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="190"></a>190</td><td></td><td></td><td></td><td></td><td class="s"> my $x;</td></tr>
<tr><td class="h"><a name="191"></a>191</td><td></td><td></td><td></td><td></td><td class="s"> try { die 'foo' } finally { $x = 'bar' };</td></tr>
<tr><td class="h"><a name="192"></a>192</td><td></td><td></td><td></td><td></td><td class="s"> try { die 'foo' } catch { warn "Got a die: $_" } finally { $x = 'bar' };</td></tr>
<tr><td class="h"><a name="193"></a>193</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="194"></a>194</td><td></td><td></td><td></td><td></td><td class="s">Finally blocks are always executed making them suitable for cleanup code</td></tr>
<tr><td class="h"><a name="195"></a>195</td><td></td><td></td><td></td><td></td><td class="s">which cannot be handled using local.</td></tr>
<tr><td class="h"><a name="196"></a>196</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="197"></a>197</td><td></td><td></td><td></td><td></td><td class="s">=head1 EXPORTS</td></tr>
<tr><td class="h"><a name="198"></a>198</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="199"></a>199</td><td></td><td></td><td></td><td></td><td class="s">All functions are exported by default using L<Exporter>.</td></tr>
<tr><td class="h"><a name="200"></a>200</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="201"></a>201</td><td></td><td></td><td></td><td></td><td class="s">If you need to rename the C<try>, C<catch> or C<finally> keyword consider using</td></tr>
<tr><td class="h"><a name="202"></a>202</td><td></td><td></td><td></td><td></td><td class="s">L<Sub::Import> to get L<Sub::Exporter>'s flexibility.</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">=over 4</td></tr>
<tr><td class="h"><a name="205"></a>205</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="206"></a>206</td><td></td><td></td><td></td><td></td><td class="s">=item try (&;@)</td></tr>
<tr><td class="h"><a name="207"></a>207</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="208"></a>208</td><td></td><td></td><td></td><td></td><td class="s">Takes one mandatory try subroutine, an optional catch subroutine & finally</td></tr>
<tr><td class="h"><a name="209"></a>209</td><td></td><td></td><td></td><td></td><td class="s">subroutine.</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">The mandatory subroutine is evaluated in the context of an C<eval> block.</td></tr>
<tr><td class="h"><a name="212"></a>212</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="213"></a>213</td><td></td><td></td><td></td><td></td><td class="s">If no error occurred the value from the first block is returned, preserving</td></tr>
<tr><td class="h"><a name="214"></a>214</td><td></td><td></td><td></td><td></td><td class="s">list/scalar context.</td></tr>
<tr><td class="h"><a name="215"></a>215</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="216"></a>216</td><td></td><td></td><td></td><td></td><td class="s">If there was an error and the second subroutine was given it will be invoked</td></tr>
<tr><td class="h"><a name="217"></a>217</td><td></td><td></td><td></td><td></td><td class="s">with the error in C<$_> (localized) and as that block's first and only</td></tr>
<tr><td class="h"><a name="218"></a>218</td><td></td><td></td><td></td><td></td><td class="s">argument.</td></tr>
<tr><td class="h"><a name="219"></a>219</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="220"></a>220</td><td></td><td></td><td></td><td></td><td class="s">Note that the error may be false, but if that happens the C<catch> block will</td></tr>
<tr><td class="h"><a name="221"></a>221</td><td></td><td></td><td></td><td></td><td class="s">still be invoked.</td></tr>
<tr><td class="h"><a name="222"></a>222</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="223"></a>223</td><td></td><td></td><td></td><td></td><td class="s">Once all execution is finished then the finally block if given will execute.</td></tr>
<tr><td class="h"><a name="224"></a>224</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="225"></a>225</td><td></td><td></td><td></td><td></td><td class="s">=item catch (&;$)</td></tr>
<tr><td class="h"><a name="226"></a>226</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="227"></a>227</td><td></td><td></td><td></td><td></td><td class="s">Intended to be used in the second argument position of C<try>.</td></tr>
<tr><td class="h"><a name="228"></a>228</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="229"></a>229</td><td></td><td></td><td></td><td></td><td class="s">Returns a reference to the subroutine it was given but blessed as</td></tr>
<tr><td class="h"><a name="230"></a>230</td><td></td><td></td><td></td><td></td><td class="s">C<Try::Tiny::Catch> which allows try to decode correctly what to do</td></tr>
<tr><td class="h"><a name="231"></a>231</td><td></td><td></td><td></td><td></td><td class="s">with this code reference.</td></tr>
<tr><td class="h"><a name="232"></a>232</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="233"></a>233</td><td></td><td></td><td></td><td></td><td class="s"> catch { ... }</td></tr>
<tr><td class="h"><a name="234"></a>234</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="235"></a>235</td><td></td><td></td><td></td><td></td><td class="s">Inside the catch block the previous value of C<$@> is still available for use.</td></tr>
<tr><td class="h"><a name="236"></a>236</td><td></td><td></td><td></td><td></td><td class="s">This value may or may not be meaningful depending on what happened before the</td></tr>
<tr><td class="h"><a name="237"></a>237</td><td></td><td></td><td></td><td></td><td class="s">C<try>, but it might be a good idea to preserve it in an error stack.</td></tr>
<tr><td class="h"><a name="238"></a>238</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="239"></a>239</td><td></td><td></td><td></td><td></td><td class="s">=item finally (&;$)</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"> try { ... }</td></tr>
<tr><td class="h"><a name="242"></a>242</td><td></td><td></td><td></td><td></td><td class="s"> catch { ... }</td></tr>
<tr><td class="h"><a name="243"></a>243</td><td></td><td></td><td></td><td></td><td class="s"> finally { ... };</td></tr>
<tr><td class="h"><a name="244"></a>244</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="245"></a>245</td><td></td><td></td><td></td><td></td><td class="s">Or</td></tr>
<tr><td class="h"><a name="246"></a>246</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="247"></a>247</td><td></td><td></td><td></td><td></td><td class="s"> try { ... }</td></tr>
<tr><td class="h"><a name="248"></a>248</td><td></td><td></td><td></td><td></td><td class="s"> finally { ... };</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">Or even</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"> try { ... }</td></tr>
<tr><td class="h"><a name="253"></a>253</td><td></td><td></td><td></td><td></td><td class="s"> finally { ... }</td></tr>
<tr><td class="h"><a name="254"></a>254</td><td></td><td></td><td></td><td></td><td class="s"> catch { ... };</td></tr>
<tr><td class="h"><a name="255"></a>255</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="256"></a>256</td><td></td><td></td><td></td><td></td><td class="s">Intended to be the second or third element of C<try>. Finally blocks are always</td></tr>
<tr><td class="h"><a name="257"></a>257</td><td></td><td></td><td></td><td></td><td class="s">executed in the event of a successful C<try> or if C<catch> is run. This allows</td></tr>
<tr><td class="h"><a name="258"></a>258</td><td></td><td></td><td></td><td></td><td class="s">you to locate cleanup code which cannot be done via C<local()> e.g. closing a file</td></tr>
<tr><td class="h"><a name="259"></a>259</td><td></td><td></td><td></td><td></td><td class="s">handle.</td></tr>
<tr><td class="h"><a name="260"></a>260</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="261"></a>261</td><td></td><td></td><td></td><td></td><td class="s">B<You must always do your own error handling in the finally block>. C<Try::Tiny> will</td></tr>
<tr><td class="h"><a name="262"></a>262</td><td></td><td></td><td></td><td></td><td class="s">not do anything about handling possible errors coming from code located in these</td></tr>
<tr><td class="h"><a name="263"></a>263</td><td></td><td></td><td></td><td></td><td class="s">blocks.</td></tr>
<tr><td class="h"><a name="264"></a>264</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="265"></a>265</td><td></td><td></td><td></td><td></td><td class="s">In the same way C<catch()> blesses the code reference this subroutine does the same</td></tr>
<tr><td class="h"><a name="266"></a>266</td><td></td><td></td><td></td><td></td><td class="s">except it bless them as C<Try::Tiny::Finally>.</td></tr>
<tr><td class="h"><a name="267"></a>267</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="268"></a>268</td><td></td><td></td><td></td><td></td><td class="s">=back</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">=head1 BACKGROUND</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">There are a number of issues with C<eval>.</td></tr>
<tr><td class="h"><a name="273"></a>273</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="274"></a>274</td><td></td><td></td><td></td><td></td><td class="s">=head2 Clobbering $@</td></tr>
<tr><td class="h"><a name="275"></a>275</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="276"></a>276</td><td></td><td></td><td></td><td></td><td class="s">When you run an eval block and it succeeds, C<$@> will be cleared, potentially</td></tr>
<tr><td class="h"><a name="277"></a>277</td><td></td><td></td><td></td><td></td><td class="s">clobbering an error that is currently being caught.</td></tr>
<tr><td class="h"><a name="278"></a>278</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="279"></a>279</td><td></td><td></td><td></td><td></td><td class="s">This causes action at a distance, clearing previous errors your caller may have</td></tr>
<tr><td class="h"><a name="280"></a>280</td><td></td><td></td><td></td><td></td><td class="s">not yet handled.</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">C<$@> must be properly localized before invoking C<eval> in order to avoid this</td></tr>
<tr><td class="h"><a name="283"></a>283</td><td></td><td></td><td></td><td></td><td class="s">issue.</td></tr>
<tr><td class="h"><a name="284"></a>284</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="285"></a>285</td><td></td><td></td><td></td><td></td><td class="s">More specifically, C<$@> is clobbered at the begining of the C<eval>, which</td></tr>
<tr><td class="h"><a name="286"></a>286</td><td></td><td></td><td></td><td></td><td class="s">also makes it impossible to capture the previous error before you die (for</td></tr>
<tr><td class="h"><a name="287"></a>287</td><td></td><td></td><td></td><td></td><td class="s">instance when making exception objects with error stacks).</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">For this reason C<try> will actually set C<$@> to its previous value (before</td></tr>
<tr><td class="h"><a name="290"></a>290</td><td></td><td></td><td></td><td></td><td class="s">the localization) in the beginning of the C<eval> block.</td></tr>
<tr><td class="h"><a name="291"></a>291</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="292"></a>292</td><td></td><td></td><td></td><td></td><td class="s">=head2 Localizing $@ silently masks errors</td></tr>
<tr><td class="h"><a name="293"></a>293</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="294"></a>294</td><td></td><td></td><td></td><td></td><td class="s">Inside an eval block C<die> behaves sort of like:</td></tr>
<tr><td class="h"><a name="295"></a>295</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="296"></a>296</td><td></td><td></td><td></td><td></td><td class="s"> sub die {</td></tr>
<tr><td class="h"><a name="297"></a>297</td><td></td><td></td><td></td><td></td><td class="s"> $@ = $_[0];</td></tr>
<tr><td class="h"><a name="298"></a>298</td><td></td><td></td><td></td><td></td><td class="s"> return_undef_from_eval();</td></tr>
<tr><td class="h"><a name="299"></a>299</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="300"></a>300</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="301"></a>301</td><td></td><td></td><td></td><td></td><td class="s">This means that if you were polite and localized C<$@> you can't die in that</td></tr>
<tr><td class="h"><a name="302"></a>302</td><td></td><td></td><td></td><td></td><td class="s">scope, or your error will be discarded (printing "Something's wrong" instead).</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">The workaround is very ugly:</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"> my $error = do {</td></tr>
<tr><td class="h"><a name="307"></a>307</td><td></td><td></td><td></td><td></td><td class="s"> local $@;</td></tr>
<tr><td class="h"><a name="308"></a>308</td><td></td><td></td><td></td><td></td><td class="s"> eval { ... };</td></tr>
<tr><td class="h"><a name="309"></a>309</td><td></td><td></td><td></td><td></td><td class="s"> $@;</td></tr>
<tr><td class="h"><a name="310"></a>310</td><td></td><td></td><td></td><td></td><td class="s"> };</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"> ...</td></tr>
<tr><td class="h"><a name="313"></a>313</td><td></td><td></td><td></td><td></td><td class="s"> die $error;</td></tr>
<tr><td class="h"><a name="314"></a>314</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="315"></a>315</td><td></td><td></td><td></td><td></td><td class="s">=head2 $@ might not be a true value</td></tr>
<tr><td class="h"><a name="316"></a>316</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="317"></a>317</td><td></td><td></td><td></td><td></td><td class="s">This code is wrong:</td></tr>
<tr><td class="h"><a name="318"></a>318</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="319"></a>319</td><td></td><td></td><td></td><td></td><td class="s"> if ( $@ ) {</td></tr>
<tr><td class="h"><a name="320"></a>320</td><td></td><td></td><td></td><td></td><td class="s"> ...</td></tr>
<tr><td class="h"><a name="321"></a>321</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="322"></a>322</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="323"></a>323</td><td></td><td></td><td></td><td></td><td class="s">because due to the previous caveats it may have been unset.</td></tr>
<tr><td class="h"><a name="324"></a>324</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="325"></a>325</td><td></td><td></td><td></td><td></td><td class="s">C<$@> could also be an overloaded error object that evaluates to false, but</td></tr>
<tr><td class="h"><a name="326"></a>326</td><td></td><td></td><td></td><td></td><td class="s">that's asking for trouble anyway.</td></tr>
<tr><td class="h"><a name="327"></a>327</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="328"></a>328</td><td></td><td></td><td></td><td></td><td class="s">The classic failure mode is:</td></tr>
<tr><td class="h"><a name="329"></a>329</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="330"></a>330</td><td></td><td></td><td></td><td></td><td class="s"> sub Object::DESTROY {</td></tr>
<tr><td class="h"><a name="331"></a>331</td><td></td><td></td><td></td><td></td><td class="s"> eval { ... }</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"></td></tr>
<tr><td class="h"><a name="334"></a>334</td><td></td><td></td><td></td><td></td><td class="s"> eval {</td></tr>
<tr><td class="h"><a name="335"></a>335</td><td></td><td></td><td></td><td></td><td class="s"> my $obj = Object->new;</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"> die "foo";</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"></td></tr>
<tr><td class="h"><a name="340"></a>340</td><td></td><td></td><td></td><td></td><td class="s"> if ( $@ ) {</td></tr>
<tr><td class="h"><a name="341"></a>341</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="342"></a>342</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="343"></a>343</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="344"></a>344</td><td></td><td></td><td></td><td></td><td class="s">In this case since C<Object::DESTROY> is not localizing C<$@> but still uses</td></tr>
<tr><td class="h"><a name="345"></a>345</td><td></td><td></td><td></td><td></td><td class="s">C<eval>, it will set C<$@> to C<"">.</td></tr>
<tr><td class="h"><a name="346"></a>346</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="347"></a>347</td><td></td><td></td><td></td><td></td><td class="s">The destructor is called when the stack is unwound, after C<die> sets C<$@> to</td></tr>
<tr><td class="h"><a name="348"></a>348</td><td></td><td></td><td></td><td></td><td class="s">C<"foo at Foo.pm line 42\n">, so by the time C<if ( $@ )> is evaluated it has</td></tr>
<tr><td class="h"><a name="349"></a>349</td><td></td><td></td><td></td><td></td><td class="s">been cleared by C<eval> in the destructor.</td></tr>
<tr><td class="h"><a name="350"></a>350</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="351"></a>351</td><td></td><td></td><td></td><td></td><td class="s">The workaround for this is even uglier than the previous ones. Even though we</td></tr>
<tr><td class="h"><a name="352"></a>352</td><td></td><td></td><td></td><td></td><td class="s">can't save the value of C<$@> from code that doesn't localize, we can at least</td></tr>
<tr><td class="h"><a name="353"></a>353</td><td></td><td></td><td></td><td></td><td class="s">be sure the eval was aborted due to an error:</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"> my $failed = not eval {</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"></td></tr>
<tr><td class="h"><a name="358"></a>358</td><td></td><td></td><td></td><td></td><td class="s"> return 1;</td></tr>
<tr><td class="h"><a name="359"></a>359</td><td></td><td></td><td></td><td></td><td class="s"> };</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">This is because an C<eval> that caught a C<die> will always return a false</td></tr>
<tr><td class="h"><a name="362"></a>362</td><td></td><td></td><td></td><td></td><td class="s">value.</td></tr>
<tr><td class="h"><a name="363"></a>363</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="364"></a>364</td><td></td><td></td><td></td><td></td><td class="s">=head1 SHINY SYNTAX</td></tr>
<tr><td class="h"><a name="365"></a>365</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="366"></a>366</td><td></td><td></td><td></td><td></td><td class="s">Using Perl 5.10 you can use L<perlsyn/"Switch statements">.</td></tr>
<tr><td class="h"><a name="367"></a>367</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="368"></a>368</td><td></td><td></td><td></td><td></td><td class="s">The C<catch> block is invoked in a topicalizer context (like a C<given> block),</td></tr>
<tr><td class="h"><a name="369"></a>369</td><td></td><td></td><td></td><td></td><td class="s">but note that you can't return a useful value from C<catch> using the C<when></td></tr>
<tr><td class="h"><a name="370"></a>370</td><td></td><td></td><td></td><td></td><td class="s">blocks without an explicit C<return>.</td></tr>
<tr><td class="h"><a name="371"></a>371</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="372"></a>372</td><td></td><td></td><td></td><td></td><td class="s">This is somewhat similar to Perl 6's C<CATCH> blocks. You can use it to</td></tr>
<tr><td class="h"><a name="373"></a>373</td><td></td><td></td><td></td><td></td><td class="s">concisely match errors:</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"> try {</td></tr>
<tr><td class="h"><a name="376"></a>376</td><td></td><td></td><td></td><td></td><td class="s"> require Foo;</td></tr>
<tr><td class="h"><a name="377"></a>377</td><td></td><td></td><td></td><td></td><td class="s"> } catch {</td></tr>
<tr><td class="h"><a name="378"></a>378</td><td></td><td></td><td></td><td></td><td class="s"> when (/^Can't locate .*?\.pm in \@INC/) { } # ignore</td></tr>
<tr><td class="h"><a name="379"></a>379</td><td></td><td></td><td></td><td></td><td class="s"> default { die $_ }</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"></td></tr>
<tr><td class="h"><a name="382"></a>382</td><td></td><td></td><td></td><td></td><td class="s">=head1 CAVEATS</td></tr>
<tr><td class="h"><a name="383"></a>383</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="384"></a>384</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="385"></a>385</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="386"></a>386</td><td></td><td></td><td></td><td></td><td class="s">=item *</td></tr>
<tr><td class="h"><a name="387"></a>387</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="388"></a>388</td><td></td><td></td><td></td><td></td><td class="s">C<@_> is not available, you need to name your args:</td></tr>
<tr><td class="h"><a name="389"></a>389</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="390"></a>390</td><td></td><td></td><td></td><td></td><td class="s"> sub foo {</td></tr>
<tr><td class="h"><a name="391"></a>391</td><td></td><td></td><td></td><td></td><td class="s"> my ( $self, @args ) = @_;</td></tr>
<tr><td class="h"><a name="392"></a>392</td><td></td><td></td><td></td><td></td><td class="s"> try { $self->bar(@args) }</td></tr>
<tr><td class="h"><a name="393"></a>393</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="394"></a>394</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="395"></a>395</td><td></td><td></td><td></td><td></td><td class="s">=item *</td></tr>
<tr><td class="h"><a name="396"></a>396</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="397"></a>397</td><td></td><td></td><td></td><td></td><td class="s">C<return> returns from the C<try> block, not from the parent sub (note that</td></tr>
<tr><td class="h"><a name="398"></a>398</td><td></td><td></td><td></td><td></td><td class="s">this is also how C<eval> works, but not how L<TryCatch> works):</td></tr>
<tr><td class="h"><a name="399"></a>399</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="400"></a>400</td><td></td><td></td><td></td><td></td><td class="s"> sub bar {</td></tr>
<tr><td class="h"><a name="401"></a>401</td><td></td><td></td><td></td><td></td><td class="s"> try { return "foo" };</td></tr>
<tr><td class="h"><a name="402"></a>402</td><td></td><td></td><td></td><td></td><td class="s"> return "baz";</td></tr>
<tr><td class="h"><a name="403"></a>403</td><td></td><td></td><td></td><td></td><td class="s"> }</td></tr>
<tr><td class="h"><a name="404"></a>404</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="405"></a>405</td><td></td><td></td><td></td><td></td><td class="s"> say bar(); # "baz"</td></tr>
<tr><td class="h"><a name="406"></a>406</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="407"></a>407</td><td></td><td></td><td></td><td></td><td class="s">=item *</td></tr>
<tr><td class="h"><a name="408"></a>408</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="409"></a>409</td><td></td><td></td><td></td><td></td><td class="s">C<try> introduces another caller stack frame. L<Sub::Uplevel> is not used. L<Carp></td></tr>
<tr><td class="h"><a name="410"></a>410</td><td></td><td></td><td></td><td></td><td class="s">will report this when using full stack traces. This lack of magic is considered</td></tr>
<tr><td class="h"><a name="411"></a>411</td><td></td><td></td><td></td><td></td><td class="s">a feature.</td></tr>
<tr><td class="h"><a name="412"></a>412</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="413"></a>413</td><td></td><td></td><td></td><td></td><td class="s">=item *</td></tr>
<tr><td class="h"><a name="414"></a>414</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="415"></a>415</td><td></td><td></td><td></td><td></td><td class="s">The value of C<$_> in the C<catch> block is not guaranteed to be the value of</td></tr>
<tr><td class="h"><a name="416"></a>416</td><td></td><td></td><td></td><td></td><td class="s">the exception thrown (C<$@>) in the C<try> block. There is no safe way to</td></tr>
<tr><td class="h"><a name="417"></a>417</td><td></td><td></td><td></td><td></td><td class="s">ensure this, since C<eval> may be used unhygenically in destructors. The only</td></tr>
<tr><td class="h"><a name="418"></a>418</td><td></td><td></td><td></td><td></td><td class="s">guarantee is that the C<catch> will be called if an exception is thrown.</td></tr>
<tr><td class="h"><a name="419"></a>419</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="420"></a>420</td><td></td><td></td><td></td><td></td><td class="s">=item *</td></tr>
<tr><td class="h"><a name="421"></a>421</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="422"></a>422</td><td></td><td></td><td></td><td></td><td class="s">The return value of the C<catch> block is not ignored, so if testing the result</td></tr>
<tr><td class="h"><a name="423"></a>423</td><td></td><td></td><td></td><td></td><td class="s">of the expression for truth on success, be sure to return a false value from</td></tr>
<tr><td class="h"><a name="424"></a>424</td><td></td><td></td><td></td><td></td><td class="s">the C<catch> block:</td></tr>
<tr><td class="h"><a name="425"></a>425</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="426"></a>426</td><td></td><td></td><td></td><td></td><td class="s"> my $obj = try {</td></tr>
<tr><td class="h"><a name="427"></a>427</td><td></td><td></td><td></td><td></td><td class="s"> MightFail->new;</td></tr>
<tr><td class="h"><a name="428"></a>428</td><td></td><td></td><td></td><td></td><td class="s"> } catch {</td></tr>
<tr><td class="h"><a name="429"></a>429</td><td></td><td></td><td></td><td></td><td class="s"> ...</td></tr>
<tr><td class="h"><a name="430"></a>430</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="431"></a>431</td><td></td><td></td><td></td><td></td><td class="s"> return; # avoid returning a true value;</td></tr>
<tr><td class="h"><a name="432"></a>432</td><td></td><td></td><td></td><td></td><td class="s"> };</td></tr>
<tr><td class="h"><a name="433"></a>433</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="434"></a>434</td><td></td><td></td><td></td><td></td><td class="s"> return unless $obj;</td></tr>
<tr><td class="h"><a name="435"></a>435</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="436"></a>436</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="437"></a>437</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="438"></a>438</td><td></td><td></td><td></td><td></td><td class="s">=head1 SEE ALSO</td></tr>
<tr><td class="h"><a name="439"></a>439</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="440"></a>440</td><td></td><td></td><td></td><td></td><td class="s">=over 4</td></tr>
<tr><td class="h"><a name="441"></a>441</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="442"></a>442</td><td></td><td></td><td></td><td></td><td class="s">=item L<TryCatch></td></tr>
<tr><td class="h"><a name="443"></a>443</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="444"></a>444</td><td></td><td></td><td></td><td></td><td class="s">Much more feature complete, more convenient semantics, but at the cost of</td></tr>
<tr><td class="h"><a name="445"></a>445</td><td></td><td></td><td></td><td></td><td class="s">implementation complexity.</td></tr>
<tr><td class="h"><a name="446"></a>446</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="447"></a>447</td><td></td><td></td><td></td><td></td><td class="s">=item L<autodie></td></tr>
<tr><td class="h"><a name="448"></a>448</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="449"></a>449</td><td></td><td></td><td></td><td></td><td class="s">Automatic error throwing for builtin functions and more. Also designed to</td></tr>
<tr><td class="h"><a name="450"></a>450</td><td></td><td></td><td></td><td></td><td class="s">work well with C<given>/C<when>.</td></tr>
<tr><td class="h"><a name="451"></a>451</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="452"></a>452</td><td></td><td></td><td></td><td></td><td class="s">=item L<Throwable></td></tr>
<tr><td class="h"><a name="453"></a>453</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="454"></a>454</td><td></td><td></td><td></td><td></td><td class="s">A lightweight role for rolling your own exception classes.</td></tr>
<tr><td class="h"><a name="455"></a>455</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="456"></a>456</td><td></td><td></td><td></td><td></td><td class="s">=item L<Error></td></tr>
<tr><td class="h"><a name="457"></a>457</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="458"></a>458</td><td></td><td></td><td></td><td></td><td class="s">Exception object implementation with a C<try> statement. Does not localize</td></tr>
<tr><td class="h"><a name="459"></a>459</td><td></td><td></td><td></td><td></td><td class="s">C<$@>.</td></tr>
<tr><td class="h"><a name="460"></a>460</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="461"></a>461</td><td></td><td></td><td></td><td></td><td class="s">=item L<Exception::Class::TryCatch></td></tr>
<tr><td class="h"><a name="462"></a>462</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="463"></a>463</td><td></td><td></td><td></td><td></td><td class="s">Provides a C<catch> statement, but properly calling C<eval> is your</td></tr>
<tr><td class="h"><a name="464"></a>464</td><td></td><td></td><td></td><td></td><td class="s">responsibility.</td></tr>
<tr><td class="h"><a name="465"></a>465</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="466"></a>466</td><td></td><td></td><td></td><td></td><td class="s">The C<try> keyword pushes C<$@> onto an error stack, avoiding some of the</td></tr>
<tr><td class="h"><a name="467"></a>467</td><td></td><td></td><td></td><td></td><td class="s">issues with C<$@>, but you still need to localize to prevent clobbering.</td></tr>
<tr><td class="h"><a name="468"></a>468</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="469"></a>469</td><td></td><td></td><td></td><td></td><td class="s">=back</td></tr>
<tr><td class="h"><a name="470"></a>470</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="471"></a>471</td><td></td><td></td><td></td><td></td><td class="s">=head1 LIGHTNING TALK</td></tr>
<tr><td class="h"><a name="472"></a>472</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="473"></a>473</td><td></td><td></td><td></td><td></td><td class="s">I gave a lightning talk about this module, you can see the slides (Firefox</td></tr>
<tr><td class="h"><a name="474"></a>474</td><td></td><td></td><td></td><td></td><td class="s">only):</td></tr>
<tr><td class="h"><a name="475"></a>475</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="476"></a>476</td><td></td><td></td><td></td><td></td><td class="s">L<http://nothingmuch.woobling.org/talks/takahashi.xul?data=try_tiny.txt></td></tr>
<tr><td class="h"><a name="477"></a>477</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="478"></a>478</td><td></td><td></td><td></td><td></td><td class="s">Or read the source:</td></tr>
<tr><td class="h"><a name="479"></a>479</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="480"></a>480</td><td></td><td></td><td></td><td></td><td class="s">L<http://nothingmuch.woobling.org/talks/yapc_asia_2009/try_tiny.yml></td></tr>
<tr><td class="h"><a name="481"></a>481</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="482"></a>482</td><td></td><td></td><td></td><td></td><td class="s">=head1 VERSION CONTROL</td></tr>
<tr><td class="h"><a name="483"></a>483</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="484"></a>484</td><td></td><td></td><td></td><td></td><td class="s">L<http://github.com/nothingmuch/try-tiny/></td></tr>
<tr><td class="h"><a name="485"></a>485</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="486"></a>486</td><td></td><td></td><td></td><td></td><td class="s">=head1 AUTHOR</td></tr>
<tr><td class="h"><a name="487"></a>487</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="488"></a>488</td><td></td><td></td><td></td><td></td><td class="s">Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt></td></tr>
<tr><td class="h"><a name="489"></a>489</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="490"></a>490</td><td></td><td></td><td></td><td></td><td class="s">=head1 COPYRIGHT</td></tr>
<tr><td class="h"><a name="491"></a>491</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="492"></a>492</td><td></td><td></td><td></td><td></td><td class="s"> Copyright (c) 2009 Yuval Kogman. All rights reserved.</td></tr>
<tr><td class="h"><a name="493"></a>493</td><td></td><td></td><td></td><td></td><td class="s"> This program is free software; you can redistribute</td></tr>
<tr><td class="h"><a name="494"></a>494</td><td></td><td></td><td></td><td></td><td class="s"> it and/or modify it under the terms of the MIT license.</td></tr>
<tr><td class="h"><a name="495"></a>495</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
<tr><td class="h"><a name="496"></a>496</td><td></td><td></td><td></td><td></td><td class="s">=cut</td></tr>
<tr><td class="h"><a name="497"></a>497</td><td></td><td></td><td></td><td></td><td class="s"></td></tr>
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