We have some very good tools for writing DSLs (Forth and Lisp come to mind). And since in both of those you in principle have access to an assembler (Lisps are

We have some very good tools for writing DSLs (Forth and Lisp come to mind). And since in both of those you in principle have access to an assembler (Lisps are less good about that nowadays, sadly) they seem like a decent option.