You already know it: the way you do this is with a homoiconic language. I don't know of any "formalisms" of homoiconic languages, but there's always Scheme. I d

You already know it: the way you do this is with a homoiconic language. I don't know of any "formalisms" of homoiconic languages, but there's always Scheme. I don't know why this idea is relevant though. If where you're going with this is "you can write code to take in a monad instance as an input syntax tree and verify it satisfies the laws", then I assure you that's impossible in the general case.