Have you got a good example where Lisp macros would work but standard Haskell would "fail"?
I've done some compiler work in Haskell like writing programs (semantic actions) as algebraic data structures and then transforming or interpreting the tree. Would I gain something by using Lisp macros in this instance?
Many of Lisp's uses of macros can be replicated in Haskell by taking advantange of lazy evaluation. This is enough for most needs I've ever had, but some things still need the macro system that Template Haskell provides. Deriving lenses from type declarations is one of the up-to-the minute uses.
I've done some compiler work in Haskell like writing programs (semantic actions) as algebraic data structures and then transforming or interpreting the tree. Would I gain something by using Lisp macros in this instance?