I appreciate it too, and I don't believe I am.
I wasn't aware it is now an integrated part of the JDK, but it doesn't change much; I've used ANTLR decades ago (and YACC even more decades ago) which is ... essentially the same thing, except Java has now standardized and simplified it so that you don't need to fiddle with your Ant or Maven or Makefile.
> Sure, it's probably not as widely used as other frameworks in other languages.
I've been doing professional work for over 30 years now, so I think I have some perspective, which may of course be different than yours. Code generators and processors have always had their niches, but that's what they are - niches - and they are quite small.
People used to use YACC, or ANTLR or Bison or Lemon or whatever your favorite parsing tool is. That's because they save an enormous amount of work in most use cases where they are applied. But they also come with great costs: Hard to debug when things go wrong, but most importantly - inflexible. GCC and many, many other projects move off parser generators at some point in their life for flexibility reasons.
Qt has MOC, which was essential in older C++ and is now IIRC optional because modern C++ has mostly caught up. It is widely hated among Qt users, though it did offer significant advantages. But I'm not aware of any project that used MOC except to interface with Qt - the boundary is always evident.
> You have not shown this. And if you mean that your C macro implementations do this -- fine. But you still seem to find them useful enough to keep using them?
How could I "show" this? It is obviously predicated on the projects I've been involved with, which - I noted - have not been Java in the last ten years. It's not like it's something that can be "shown", except in some statistical sense, the validity of which we will argue forever.
And yes, people shy away from macro heavy C code (whenever J source code or A source code gets posted on HN, people are less than happy, e.g. https://news.ycombinator.com/item?id=8533843 ; the whole J system looks like that ).
I use macro heavy code only when I don't have to share it with others, for that reason.
> But using a very simple code generator for a very simple problem is not the same thing.
Well, perhaps we're not thinking of the same level of simple - e.g. c++ template meta programming, which I first used in 1995 is built in, and (literally) turing complete, so it can do anything, but is far from "simple" - not to actually write, not to use, and definitely not to debug.
What I had in mind was things like https://github.com/Hirrolot/poica - It uses C macros to do incredible magic. All it needs is one #include and it gives C introspection, oop and a few other things. Is it simple? I wouldn't say that. But more importantly, is it C ? I wouldn't say that, and so does the guy who made it. It can be used in a C program, yes. It can e.g. go further and define comparators for you so you can use qsort() on the new types it helps you define. But it's not really C because when you try to integrate it with an existing C codebase, you'll find that you keep having to translate things at every boundary - which is quite likely to happen with a Java SoA library.
I think my point is that languages in common use (Java, C, C#, ...), despite offering the facilities to locally solve the issues described in the original article (locality of reference mostly), they do not practically allow these solutions to become widespread or common because they are not part of the core, and as a result you lose all benefits on library boundaries.