From: "Bartosz Dziewoński" <matma.rex@...>
Date: 2012-08-04T06:26:14+09:00
Subject: Re: YAML.to_s in JRuby

It's the same in MRI Ruby 1.9.3.

irb(main):001:0> require 'yaml'
=> true
irb(main):002:0> YAML
=> Psych

Between 1.8 and 1.9 old YAML parser and generator was scrapped and
replaced with a new one called Psych. There is probably a line like
"YAML = Psych" somewhere in Ruby stdlib, for backwards compatibility.

-- Matma Rex