Ruby: required keyword arguments in the pre-2.1 era

Starting with Ruby 2.0 you can define methods with keyword arguments.

In 2.1+ required keyword arguments can be defined by using a colon without default value:

Copydef match(value, ignore:)
  # ...
end

To accomplish something similar in ruby 1.8, use:

Copydef match(value, options = {})
  ignore = options.fetch(:ignore)
  # ...
end