# Extend the File class to add a function to check for a file in the 
# load path.

class File
  # find a file in the load path or raise an exception if the file can
  # not be found.
  def File.find_file_in_path(filename)
    $:.each do |path|
      file_with_path = path+'/'+filename
      return file_with_path if file?(file_with_path) 
    end
  
    raise ArgumentError, "Can't find file #{filename} in Ruby library path"
  end
end