In practice though it doesn't give you any of the tools you need to do anything except make tools to do those things. Which appeals to yak-shavers like us for sure. But if you need to sit down with it for months at a time and just get work out the door it fucking sucks.
Also 5.1's GC is goddamn tragic. In practice you're usually at the mercy of whatever was implemented by the embedding runtime, but if you're ever left alone with just the raw 5.1 GC you'll wish you weren't. Later versions improved that dramatically.
> you're usually at the mercy of whatever was implemented by the embedding runtime
Are we talking about the same Lua? The engines I know (PUC Rio and LuaJIT) are not at the mercy of embedding runtimes, but haver their own, sufficiently good memory management.
I'm not an expert user of anything though, or building tools. My professional experience of it has been using ancient versions that are embedded into C or C++ systems to build simple guis and automation within those systems. I don't think it's well suited to this, but this is a common (I believe even it's original?) use case!
I've never used luajit, or any version where I had full control over the runtime at all. I understand people love this language and I'm not saying they're wrong to. But for the things I've needed to use it for it has not been enjoyable at all, particularly 5.1 which is the one I have the most experience with by far.
> I'm not an expert user of anything though
But apparently confident enough to make negative comments about the technology.
I might be wrong about the technical reasons why, and I'm genuinely sorry if I've unfairly maligned your baby here. But it has always been unpleasant for me and I think I'm entitled to my confidence about my own experiences in it.
I have, yes, it's great. No complaints, would choose LuaJIT again.
I do regret that the quad-color collector will likely never be implemented, I'd content myself with a back-port of the new generational collector, but the allocation sinking in LuaJIT has kept me out of trouble for the most part since it can put 'tables' on the stack if it can prove they don't escape.
The main practical issues I've run into with 5.1:
- per-object overhead in time and space both increased significantly, making many small allocations much more expensive than fewer big ones. further pushing you into the "mutate a few huge global tables" pattern that is already a problem in lua conventions.
- some of lua's more lauded and genuinely powerful features, esp metatables, don't work smoothly or predictably with the GC. it leads to people trying to manually tune it with __gc metamethods, which is hard to do correctly and causes memory leaks if done incorrectly.
- weak tables idk,. esp with strings for some reason. similar to the __gc, there is a solution there but in practice it's very hard to be sure you've got it right and it's worse to get it wrong than to not try.