module Psych

Psych.dump_stream("foo\n ", {}) # => "--- ! \"foo\\n \"\n--- {}\n"

Example:

Dump a list of objects as separate documents to a document stream.
##

def self.dump_stream *objects
  visitor = Psych::Visitors::YAMLTree.create({})
  objects.each do |o|
    visitor << o
  end
  visitor.tree.yaml
end