monadic.rb

module Prelude
  class Monadic
    include Dry::Monads[:maybe, :result, :do]

    def call(id, item_id)
      users = [:user]
      items = []
      user, item = yield Maybe(users[id]).and(Maybe(items[item_id])).to_result {
        'User not found'
      }
      
      Success(user: user, item: item)
    end
  end
end