I should imagine it wraps all values in its own flexible typed wrapper class and defines code for operations on them. This, of course, imposes quite an overhead.
Sometimes. The primitive types Mug can work with are `double`, `boolean`, `String`, and `JSObject`. This allows arithmetic operations and conditionals to be compiled without wrapping objects, and actual object invocations to be autoboxed as they are in JavaScript (like "a = 10" vs "a = new Number(10)")
The gaudy part is that there is only one type of function signature, basically "invoke(Object, Object, Object...)" which means Mug has to convert doubles to Doubles and booleans to Booleans across function calls... so it's somewhat of a tradeoff.
