decode Diablo II's CubeMain.bin

gistfile1.rb

#!/usr/bin/env ruby
#   dump_cubemain.rb
#
#   Copyright 2015 Bartosz Jankowski
#
#   Licensed under the Apache License, Version 2.0 (the "License")
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http:#www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#

require 'bindata'

class CubeMainInput < BinData::Record  # size 0x08
  uint8    :input_flags 			#0x00
  uint8    :item_type		    #0x01
  uint16le :item			      	#0x02
  uint16le :item_id			    #0x04
  uint8    :quality		    	#0x06
  uint8    :quantity		    	#0x07
end

class CubeMainOutputMod < BinData::Record # size 0xC
  uint32le :mod			  	#0x00
  uint16le :mod_param		#0x04
  uint16le :mod_min			#0x06
  uint16le :mod_max			#0x08
  uint16le :mod_chance	#0x0a
end

class CubeMainOutput < BinData::Record # size 0x54
  uint8    :item_flags			#0x00
  uint8    :item_type			  #0x01
  uint16le :item			    	#0x02
  uint16le :item_id			  	#0x04
	uint16le :param           #0x06
  uint8    :type			    	#0x08
  uint8    :lvl			    	  #0x09
  uint8    :p_lvl			    	#0x0a
  uint8    :i_lvl			    	#0x0b
  array    :prefix_id, :type => :uint16le, :initial_length  => 3	#0x0c
  array    :suffix_id, :type => :uint16le, :initial_length  => 3  #0x12
  array    :mods, :type => :cube_main_output_mod, :initial_length => 5 #0x18
end

class CubeMainBinRecord < BinData::Record # size 0x148
  uint8    :enabled			#0x00
  uint8    :ladder		  #0x01
  uint8    :mindiff			#0x02
  uint8    :class_id		#0x03
  uint32le :op				  #0x04
  uint32le :param			  #0x08
  uint32le :value_id		#0x0c
  uint16le :numinputs		#0x10
  uint16le :version			#0x12
  array    :inputs, :type => :cube_main_input, :initial_length  => 7
  array    :outputs, :type => :cube_main_output, :initial_length  => 3
end

class CubeMainBin < BinData::Record # size 4+
  uint32le :record_count
  array    :records, :type => :cube_main_bin_record, :initial_length  => :record_count
end


begin
  f = ARGV[0] unless ARGV[0].nil?
  bin = File.read(f)

  CubeMainBin.read(bin).records.each_with_index do |rec, num|
    puts "Record #{num} #{rec.to_binary_s.length}"
    p rec
  end
end

There is my problem:

C:\Program Files\Ruby26-x64\bin>ruby.exe cubdcode.rb cubemain.bin
Traceback (most recent call last):
6: from cubdcode.rb:38:in <main>' 5: from cubdcode.rb:44:in class:CubeMainOutput'
4: from C:/Program Files/Ruby26-x64/lib/ruby/gems/2.6.0/gems/bindata-2.4.8/lib/bindata/dsl.rb:46:in method_missing' 3: from C:/Program Files/Ruby26-x64/lib/ruby/gems/2.6.0/gems/bindata-2.4.8/lib/bindata/dsl.rb:120:in method_missing'
2: from C:/Program Files/Ruby26-x64/lib/ruby/gems/2.6.0/gems/bindata-2.4.8/lib/bindata/dsl.rb:183:in parse_and_append_field' 1: from C:/Program Files/Ruby26-x64/lib/ruby/gems/2.6.0/gems/bindata-2.4.8/lib/bindata/dsl.rb:417:in validate_field'
C:/Program Files/Ruby26-x64/lib/ruby/gems/2.6.0/gems/bindata-2.4.8/lib/bindata/dsl.rb:435:in ensure_valid_name': field 'type' is a reserved name (NameError) 1: from cubdcode.rb:38:in

'
cubdcode.rb:44:in `class:CubeMainOutput': field 'type' is a reserved name in CubeMainOutput (NameError)