json.rb for rgss?

json.rb

# coding: utf-8
# pure ruby json implementation

module JSON
  def self.parse json
    ret = nil
    json.slice!(/^\s+/)
    case
    when json.slice!(/^null/)
      ret = nil
    when json.slice!(/^false/)
      ret = false
    when json.slice!(/^true/)
      ret = true
    when raw = json.slice!(/^[-]?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][-+]?\d+)?/)
      ret = (Integer(raw) rescue Float(raw))
    when raw = json.slice!(/^\"(?:\\.|[^"])*\"/)
      ret = eval(raw.force_encoding('utf-8'))
    when json.slice!(/^\[/)
      ret = []
      until json.slice!(/^\]/)
        ret << parse(json)
        json.slice!(/^,/)
      end
    when json.slice!(/^\{/)
      ret = {}
      until json.slice!(/^\}/)
        key = parse(json)
        json.slice!(/^:/)
        value = parse(json)
        ret[key] = value
      end
    else
      raise ArgumentError, 'expect json string'
    end
    json.slice!(/^\s+/)
    ret
  end
end

JSON.parse '"#{p self}"' # injection!