#!/usr/bin/perl -w


$|++;
use strict;
use Benchmark;

# my first take - 'mine-less-lgnt' in test.
sub getpropstr
{
	local $_ = shift;
	my $level = shift || 0;
    if ( $level == -1 ) { /([^()]+)\)+$/; return $1 }
	while ( $level-- > 0)
	{
		chop;
		s/^[^(]+\(//;
	}
	return $_;
}

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

if(1)
{
for (@data)
{
	print "$_\n";
	print getpropstr( split ), "\n" ;
	print get_proparg( split ), "\n" ;
	print prop3( split ), "\n" ;
	print peeln( split ), "\n" ;
}
}

my $count = 15000;

timethese
(
	$count, 
	{
		'mine' => sub { for (@data) { prop3( split ); } },
		'mine-less-lgnt' => sub { for (@data) { getpropstr( split  ); } },
		'his' =>  sub { for (@data) { get_proparg( split ); } },
		'other' =>  sub { for (@data) { peeln( split ); } },
	}
);

# BrowserUK's version 'other' in test
sub peeln {
   local $_ = shift;
   my $n = shift || 0;
   my($c) = (tr[(][]);
   # warn 'Unbalanced parens' unless $o == $c;
   $n = $c if $n == -1;
   m[^ (?: .*? \( .*?){$n} (.+) (?: .*? \) .*?){$n} $]x;
   $1;
}


# original poster's (Fatvamp) 'his' in test
sub get_proparg {
 my $propstr = shift;         # get the property string
 my $level   = shift || 0;    # get the level we want to extract
 my $back    = $propstr;      # Initialize Return value (for case level=0)
 my $cnt;                     # initialize counter

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

 return $propstr;
}

# my cleaner version 'mine' in test
sub prop3
{
	my $str = shift;
	my $level = shift || 0;
	return $str unless $level;
	my @str = split(/[()]/, $str);
	splice @str, 0, $level;
	my $out = join('(', @str);
	$out .= ')' x ( @str - 1 );
	return $out;
}


__END__
hello(what(is(this(all(about))))) 0
hello(what(is(this(all(about))))) 1
hello(what(is(this(all(about))))) 2
hello(what(is(this(all(about))))) 3
hello(what(is(this(all(about))))) 4
hello(what(is(this(all(about))))) 5
hello(what(is(this(all(about))))) -1