class Rack::QueryParser

def normalize_params(params, name, v, depth)
  raise ParamsTooDeepError if depth <= 0
  name =~ %r(\A[\[\]]*([^\[\]]+)\]*)
  k = $1 || ''
  after = $' || ''
  if k.empty?
    if !v.nil? && name == "[]"
      return Array(v)
    else
      return
    end
  end
  if after == ''
    params[k] = v
  elsif after == "["
    params[name] = v
  elsif after == "[]"
    params[k] ||= []
    raise ParameterTypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    params[k] << v
  elsif after =~ %r(^\[\]\[([^\[\]]+)\]$) || after =~ %r(^\[\](.+)$)
    child_key = $1
    params[k] ||= []
    raise ParameterTypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    if params_hash_type?(params[k].last) && !params_hash_has_key?(params[k].last, child_key)
      normalize_params(params[k].last, child_key, v, depth - 1)
    else
      params[k] << normalize_params(make_params, child_key, v, depth - 1)
    end
  else
    params[k] ||= make_params
    raise ParameterTypeError, "expected Hash (got #{params[k].class.name}) for param `#{k}'" unless params_hash_type?(params[k])
    params[k] = normalize_params(params[k], after, v, depth - 1)
  end
  params
end