#!/usr/bin/perl
# The Missing Textutils, Ondrej Bojar, obo@cuni.cz
# http://www.cuni.cz/~obo/textutils
#
# 'indent_brackets.pl' processes stdin to stdout, indenting accoring to ()
# Useful e.g. for Collins/PennTreeBank-style trees or Moses 'python lattice
# format'.
#
# $Id: indent_brackets.pl,v 1.1 2010-10-25 12:31:59 bojar Exp $

use strict;

my $depth = 0;
my $terminal = 1;
sub action {
  my $char = shift;
  my $out;
  if ($char eq "(") {
    $out = "\n" if $depth > 0;
    $out .= "  " x $depth;
    $out .= "(";
    $terminal = 1;
    $depth++;
  } else {
    # closing bracket
    $depth--;
    if (!$terminal) {
      $out = "\n";
      $out .= "  " x $depth;
    }
    $out .= ")";
    $terminal = 0;
  }
  return $out;
}

while (<>) {
  chomp;
  # walk the chars
  $depth = 0;
  s/([\(\)])/action($1)/ge;
  print $_;
  print "\n";
}