I was working on my twitterstream package the other day and got thinking. When do you make a new type? When don't you make a new type? Type System Basics If you use a programming without a strong static type system, you probably don't have much to worry about. In ruby and python for example, it doesn't really care about what you pass a method or function, as long as it has whatever methods you expect it to have. This is called duck typing The Go…