如何从BasicObject中访问Ruby类型名称

Question

How do I access Ruby type names from within BasicObject ? I understand that "... common classes will not be found without using a full class path", but I don't know the syntax for specifying the full class path.

The code below fails because Hash isn't imported into BasicObject .

class Basic < BasicObject
  def flexible(data)
    if (data.is_a?(Hash))
      puts "It's a hash!"
    end
  end
end


foo = Basic.new
foo.flexible({})

Answer 1

To answer your immediate question, you can access Hash like so:

if (data.is_a?(::Hash))
  puts "It's a hash!"
end

This will still fail for a different reason, which is because BasicObject doesn't include Kernel , so puts is not available:

undefined method `puts' for #<Basic:0x000055c405afbc88>

If you do this as well:

class Basic < BasicObject
  include ::Kernel

or this instead:

::Kernel.puts "It's a hash!"

Then it should work as expected.