> Lisp macros operate on a representation of the AST. The representation of the AST is the AST in Lisp (Scheme has syntax objects). > By overhead I mean the n

> Lisp macros operate on a representation of the AST. The representation of the AST is the AST in Lisp (Scheme has syntax objects). > By overhead I mean the nim compiler can generate direct specific instatiations at compile time instead of doing runtime based duck-typing as in lisp. SBCL has `deftransform`, which allows macro expansions to benefits from static type analysis.