How to organize exceptions in your library

exceptions.rb

# Suppose you were designing a library named "Zippo".
# How would you organize the exceptions thrown by the library.

# Option 1
# All library errors inheriting from a common base

module Zippo
  class ZippoError < StandardError; end
  class ZippoArgumentError < ZippoError; end
  class ZippoTypeError < ZippoError; end
  # ...
end

# Option 2
# Library errors inheriting from existing Ruby errors
# (at least where appropriate)

module Zippo
  class ZippoArgumentError < ArgumentError; end
  class ZippoTypeError  < TypeError; end
end

# Option 3
#
# If you are going to throw and argument error, just throw the
# existing Ruby ArgumentError.  If you have errors that don't map to
# existing errors, go with option 1.