ORI should work outside of a readline environment

[janlelis]

Hey @dadooda,
first of all, thanks for this gem, it still work fabulous after all that time!

One little thing is that I've noticed the gem fails if it is not in a readline context. Reproducible like this:

ruby -r ori -e "p [].ri :reverse"
# …/ori-0.1.0/lib/ori/internals.rb:187:in `do_history': uninitialized constant ORI::Internals::Readline (NameError)

It also fails when readline is required:

ruby -r readline -r ori -e "p [].ri :reverse"
# …/ori-0.1.0/lib/ori/internals.rb:282:in `get_ri_arg_prefix': undefined method `match' for nil:NilClass (NoMethodError)

Here is an idea for a patch (for the latter problem):

  module ORI::Internals
    def self.get_ri_arg_prefix(cmd)
      if cmd && (mat = cmd.match /\A(\s*.+?\.ri)\s+\S/)
        mat[1]
      end
    end
end

• Ruby version 2.6.2