#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

sub parse
{
  my $str=shift;
  my $tree={};
  my @now=(\$tree);
  while($str ne '')
  {
    $str=~s/^\s*//s;
    if($str=~s/^:(\w+)\s*\(//s)
    {
      my $name=$1;
      unshift(@now,\${$now[0]}->{$name});
    }
    elsif($str=~s/^\)//)
    { shift(@now); }
    elsif($str=~s/^"([^"]+)"//s)
    {
      my $text=$1;
      # ignore \"
      while($text=~s/\\"$/"/)
      { $text.=$1 if($str=~s/^([^"]+)"//s) }
      ${$now[0]}->{TEXT}.=$text;
    }
    elsif($str=~s/^(\w+)//)
    { ${$now[0]}->{TEXT}.=$1; }
    elsif($str ne '')
    { die("FORMAT ERROR ($str)\n"); }
  }

  return $tree;
}


my $str=<<EOT;
:document ("NAME"
   :headline ("blablabla")
   :paragraph (
      :text (bli)
      :whatever (bla)
   )
)
EOT

print Dumper(parse($str));