Comment by gruseom
18 years ago
Presumably you have the entire program represented as a top-level tree, and a global optimization would be a transformation of that. I don't see why macros wouldn't be just as applicable here as in the local case where you're transforming a subtree.
I guess u are right. Macros people usually write are local but macros are just AST transformers after all. I was confusing between what happens during macro expansion (arbitrary computation including lets say doing any analysis and building metadata) versus the result of the macro expansion (a transformed AST).