This makes sense. You're totally right about the database. I've run into that issue before, but I had forgotten. Your example is similar to the approach that

This makes sense. You're totally right about the database. I've run into that issue before, but I had forgotten. Your example is similar to the approach that Yesod, a Haskell web-framework, takes. The templating language, Hamlet, will accept many types, such as Text or String, but ultimately everything gets translated into RepHTML before being rendered to a real HTML string that is sent to the client. Whenever you give the template a value it automatically runs the appropriate conversion function based on type to generate something safe for display on the page. The only way to get from a String to RepHTML is either to use the proper escaping function (usually done automatically) or use a special function to do an unsafe conversion, forcing you to explicitly state that a conversion is safe. The type system is one of the tools used to guarantee that these things get sanitized. You can generate RepHTML in other places, such as through a widget, or other helper functions, and it knows at that point that you properly escaped it. Without the type system you could run into issues when a function generates HTML (sanitized) and then the final template re-sanitizes it. It would be very awkward to do things like layout templates if things are getting sanitized many times.