view a diff of two ruby objects using pp and your difftool

Object#vdiff method for ruby

$vdiff_difftool = 'ksdiff'

require 'pp'
class Object
  def vdiff(other)
    require 'tempfile'
    t1 = Tempfile.new(['vdiff', '.rb'])
    t2 = Tempfile.new(['vdiff', '.rb'])
    PP.pp self, t1
    PP.pp other, t2
    `#{$vdiff_difftool} #{t1.path} #{t2.path}`
    t1.close
    t2.close
  end
end
class Hash
  def each_sorted_pair
    self.keys.sort.each do |k|
      yield k, self[k]
    end
  end
end
module PP::PPMethods
  def pp_hash(obj)
    group(1, '{', '}') {
      seplist(obj, nil, :each_sorted_pair) {|k, v|
        group {
          pp k
          text '=>'
          group(1) {
            breakable ''
            pp v
          }
        }
      }
    }
  end
end