require 'itex2MML'
require 'thread'

module Itex2MML
  class Error < RuntimeError; end
 
  class Parser
    def self.semaphore
      @semaphore ||= Mutex.new
    end
   
    def html_filter(string)
      parse(string, :itex2MML_html_filter)
    end
   
    def filter(string)
      parse(string, :itex2MML_filter)
    end
 
  private
 
    def parse(string, message)
      string = string.to_str
      self.class.semaphore.synchronize do
        raise Itex2MML::Error unless Itex2MML.send(message, string, string.length) == 0
        Itex2MML.itex2MML_output
      end
    end
  end
end