#!/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 extract
 my $cnt;                                 # initialize counter

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