Loader.rb

$LOAD_PATH << './'
require 'Global.rb'
require 'Exception.rb'

class Loader
	attr_reader :alphabet
	attr_reader :tape
	attr_reader :rules
	def initialize(path)
		@rules = []
		File.open(path).each do |line|
			if line.length == 1
				next
			end
			begin
				r = line.rindex(';') - 1
			rescue
				raise ParseException.new("Syntax error near \' "+line+" \', ';' Expected")
			end
			if line =~ /^TAPE=>/
				if tape == nil
					@tape = line[6..r]
				else
					raise ParseException.new("multiple tapes found")
				end
			elsif line.match(/^RULE=>/)
				parseRule(line[6..r])
			elsif line.match(/^ALPH=>/)
				if alphabet == nil
					@alphabet = line[6..line.length-2]
				else
					raise ParseException.new("multiple alphabet found")
				end
			else
				raise ParseException.new("Syntax error near \'" + line +" \'")
			end
		end
		if alphabet == nil or alphabet == ''
			raise ParseException.new("No alphabet found in this file")
		elsif tape == nil or tape == ''
			raise ParseException.new("No tape found in this file")
		elsif rules.length < 5
			raise ParseException.new("No rules found in this file")
		end
	end

	def parseRule(rule)
		r = rule.split(' ')
		if r.length != 5
			raise ParseException.new("Syntax error near \'" + rule + " \'")
		else
			r.each do |e|
				rules.push(e)
			end
		end
	end
end