#!/usr/bin/perl -w


$|++;
use strict;
use Benchmark;


#
# not so elegant but still the chanp.
sub getpropstr
{
    local $_ = shift;
    my $level = shift || 0;
    if ( $level == -1 ) { /([^()]+)\)+$/o; return $1 }
    while ( $level-- > 0)
    {
        chop;
        s/^[^(]+\(//o;
    }
    return $_;
}

my @data = <DATA>;
chomp @data;


my $count = 7000;

timethese
(
    $count, 
    {
        'my best: getpropstr' => sub { for (@data) { getpropstr( split
+  ); } },
        'OP best: get_proparg_new' =>  sub { for (@data) { get_proparg
+_new( split ); } },
        'orig-arg2' =>  sub { for (@data) { arg2( split ); } },
        'yours' =>  sub { for (@data) { arg3( split ); } },
    }
);




sub arg2 
{
    my($str,$lvl)= @_;
    my $str1 = $str;
    return $str if !$lvl;
    if ( $lvl == -1 )
    {
        $str =~ /\(([^\(\)]+)\)+/;
        return $1;
    }

    $str =~ /([^(]*\(){$lvl}(.+)(\)){$lvl}/;
    return $2;

}

sub arg3
{
    my($str,$lvl)= @_;
    my $str1 = $str;
    return $str if !$lvl;
    if ( $lvl == -1 )
    {
        $str =~ /\(([^\(\)]+)\)+/;
        return $1;
    }
    
    $str =~ /\A
    (?>  (?> [^(]* \( ) {$lvl}  )
    ( .+ )
    \) {$lvl}
    \z/x;
    return $1;
}







# the original poster's improved version
sub get_proparg_new {
 my $propstr = shift;                     # get the property string
 my $level   = shift || return $propstr;  # get the level we want to e
+xtract
 my $cnt;                                 # initialize counter

 if($level == -1) {           # special case, get the innermost argume
+nt
   $propstr =~ /\(([^\(\)]+)\)+/o;
   return $1;
 } else {                     # get whatever argument $level indicates
   for($cnt = 0;$cnt<$level; $cnt++) {
     $propstr =~ /\((.+)\)/o;
     $propstr = $1;
   }
   return $propstr;
 }
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