[dreamcompiler]

That's true but it's not the most important aspect of macros. Macros let you define a new language that describes your problem solution more directly than you can in raw Lisp. In other words they let you create a Domain-Specific Lamguage (DSL). You can create DSLs in other languages too but it's so difficult that it's uncommon. In Lisp it's so easy that DSLs are a primary programming technique.

[klibertp]

I don't think that moving the evaluation to compile time is something you can just ignore when discussing macros. It's an important differentiator between macros and Fexprs[1].

IME, the primary use case for macros in Lisps is language extension, a step before a DSL. For every `loop` there are thousands of `with-x` macro implementations. See the macro-writing macros in Alexandria/Serapeum for the most common patterns.

Also, some dynamic languages (Io, Prolog, Groovy) support DSLs through non-macro mechanisms. DSLs in those languages are as easy (or easier) to implement as in Lisps; however, they tend to be less performant. So, again, compile-time macro execution does matter for the DSL use case, too.

[1] https://en.wikipedia.org/wiki/Fexpr

[ux266478]

In the case of Prolog, term and goal expansion are arbitrary compile-time execution mechanisms, completely isomorphic with macros, and are referred to as macro mechanisms.

The characterization of it not being "compile-time macro execution" is strange, what do you think these predicates are doing?

[klibertp]

Good point. I was thinking about meta-interpreters (and it's still possible I misunderstood or misremembered how they work!), but you're right; I should have at least been more precise.