The above snippet is a MemberExpression that necessitates the implicit
construction of a StringObject wrapper around a PrimitiveString.
We then do a property lookup (a "get") on the StringObject, where we
find the "length" property. This is pretty neat! :^)
I always tell people to start building things by working on the thing
that seems the most interesting right now. The most interesting thing
here was an AST + simple interpreter, so that's where we start!
There is no lexer or parser yet, we build an AST directly and then
execute it in the interpreter, producing a return value.
This seems like the start of something interesting. :^)
