Read and write YAML files without destroying anchors and aliases?

Question

I need to open a YAML file with aliases used inside it:

defaults: &defaults
  foo: bar
  zip: button

node:
  <<: *defaults
  foo: other
         


        

Answer 1

YAML has aliases and they can round-trip, but you disable it by hash merging. << as a mapping key seems a non-standard extension to YAML (both in 1.8's syck and 1.9's psych).

require 'rubygems'
require 'yaml'

yaml = <

prints

--- 
defaults: &id001 
  zip: button
  foo: bar
node: *id001

but the << in your data merges the aliased hash into a new one which is no longer an alias.