DB<11> p join "\n", map { "$_   $#{$_}" } grep /_<\(/, keys %::
_<(eval 20)[tt:11]   -1
_<(eval 22)[/usr/lib/perl5/5.8.8/SelfLoader.pm:38]   6
_<(eval 11)[/usr/lib/perl5/5.8.8/SelfLoader.pm:111]   1
_<(eval 12)[/usr/lib/perl5/5.8.8/SelfLoader.pm:38]   40
_<(eval 5)[/usr/lib/perl5/5.8.8/Term/ReadLine.pm:306]   -1
_<(eval 21)[/usr/lib/perl5/5.8.8/SelfLoader.pm:38]   10
_<(eval 23)[/usr/lib/perl5/5.8.8/SelfLoader.pm:38]   20
_<(eval 26)[/usr/lib/perl5/5.8.8/perl5db.pl:628]   4

DB<13> f eval 22
Choosing (eval 22)[/usr/lib/perl5/5.8.8/SelfLoader.pm:38] matching `eval 22':
1       package readline; sub F_PreviousHistory {
2:          &get_line_from_history($rl_HistoryIndex - shift);
3       }
4 
5 
6       ;