Subject: Re: bug#76132: Clojure-style auto-gensyms for macros

From: Stefan Monnier <[email-masked]>
Date: Sun, 23 Feb 2025 11:19:53 -0500

Tassilo Horn [2025-02-23 10:11:08] wrote:
> Stefan Kangas <[email-masked]> writes:
>> So what's the conclusion here?  
> Macros (in the presence of eager macro expansion) are hard. :-)

Historical notes about "eager macro expansion":

- Macros have been expanded eagerly in Emacs since the introduction of
  a byte-compiler, i.e. before even Emacs-18.
- Macros are designed specifically to allow "eager macro expansion".
  In early Lisp there was another mechanism which supported only lazy
  expansion, called [fexpr](https://en.wikipedia.org/wiki/Fexpr).
  They died because of their fundamental incompatibility with compilation.

        Stefan