All interpreters do it on some level, they just don't expose this functionality to user.
As soon as you want to expose it to user in a non cumbersome way, you realize that the thing that stands in your way is the syntax of your language -- converting from textual and structural representation back and forth does not look like the way to go. You need to get rid of one of them for it to make sense. But if you get rid of textual representation, you'll just get another Lisp.
As soon as you want to expose it to user in a non cumbersome way, you realize that the thing that stands in your way is the syntax of your language -- converting from textual and structural representation back and forth does not look like the way to go. You need to get rid of one of them for it to make sense. But if you get rid of textual representation, you'll just get another Lisp.