A type adds meaning to plain bytes: it lets us say “these bytes are text,” “those bytes are an airline reservation,” and so on. Usually, a type system goes beyond this to prevent us from accidentally mixing up types. For example, a type system usually won’t let us treat a hotel reservation as a car rental receipt.
Type Systems. tl;dr version
Share this highlighthttp://www.safaribooksonline.com/a/real-world-haskell/19733100/