| Lisp "advocacy" often touts the power of macros in an abstract and unconvincing way. Persuasion by explanation isn't very effective. I'm not very interested in persuading others that Lisp macros are necessary, and there are many languages I like to use that don't have macros. However! Yes, all programming languages are programmable. But Lisp tends to be unlimited in its programmability, in almost the same way that Unix is: if you have root, you can change anything. I'm pretty sure that in most Common Lisp systems, you can redefine large parts of the compiler at runtime. And so on. Syntactic macros are just one part. They can be extremely handy. Lots of Lisp systems use them well. Random examples: the DEFSYSTEM macro of ASDF; the DEFINE-EASY-HANDLER macro of Hunchentoot (a Common Lisp web server); the (controversial) LOOP and ITERATE macros; etc. Another somewhat random example: Movitz was (is?) a project to write an x86 kernel in Common Lisp. It actually included its own compiler. It defines a lot of macros for instruction definition [0] and uses them in code that I don't understand anything of [1] but is probably very clear to someone versed in assembly. Recently I've been trying to add some nice logging to a JavaScript program, and it's a typical scenario where the normal syntax is just annoying enough to make the code ugly and hard to scan—if I had macros, I could invent some other syntax. How to use macros is a tradeoff that I guess comes with Lisp experience, but they can be a powerful escape when the standard syntax is annoying, and a way to define your own DSLs without restriction. [0]: https://common-lisp.net/viewvc/movitz/ia-x86/def-instr.lisp?... [1]: https://common-lisp.net/viewvc/movitz/ia-x86/instr-add.lisp?... |