grammar

#!/usr/bin/env ruby

# adds lib directory to Gem path
$LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))

# shortcut notation to require gems
%w{ grammar optparse regexTokenStream nfa dfa }.each { |gem| require gem }

# object to parse command line options
options = {}
OptionParser.new do |opts|
	opts.banner = "Usage: grammar [OPTIONS] [FILE]"

	opts.on("-o NAME", "--output=NAME", "output Graph to file") do |file|
		options[:output] = file
	end

	opts.on("-t TYPE", "--type=TYPE", "type to compile to graph to. Default is png") do |type|
		options[:type] = type.to_sym
	end

	opts.on("-s", "--simplify", "simplify regular expression parse tree") do |opt|
		options[:simplify] = opt
	end

	opts.on("-r", "--regex", "accept a regular expression in a file in place of a token file") do |opt|
		options[:regex] = opt
	end

	opts.on_tail("-h", "--help", "Show this message") do
		puts opts
		exit
	end
end.parse!

grammar = Grammar.new ARGV.first
puts grammar.to_s

puts "\nItem sets: "
grammar.get_item_sets.each_with_index do |item_set, i|
  puts "Item set #{i}:"
  item_set.each do |lhs, rhs_array|
    rhs_array.each do |rhs|
      puts "\t#{lhs} -> #{rhs.join(" ")}"
    end
  end
end


if options[:regex]
  tokens = RegexTokenStream.new "#{ARGV[1]}"
else
  tokens = TokenStream.new "#{ARGV[1]}"
end

parse_tree = grammar.makeTree tokens

if options[:simplify]
    parse_tree.simplify!
    
    nfa = Nfa.new(parse_tree)

    puts nfa

    dfa = Dfa.new(nfa)

    puts dfa
end

options[:output] ||= "parse_tree.png"

type = File.extname(options[:output]).delete(".")
type.empty? ? :png : type.to_sym

parse_tree.to_graphviz options[:output], :type => type