7 ms·

For those of us who are only half paying attention, how does this compare to Terra[1]? Are you using something (e.g. LLVM) for code generation? Can you genera

For those of us who are only half paying attention, how does this compare to Terra[1]? Are you using something (e.g. LLVM) for code generation? Can you generate binaries that are independent of the Lua runtime? [1]: http://terralang.org/ http://terralang.org/

nerpderp83 8y ago
They emit C and call out to the system C compiler. They bypass the normal Lua extension mechanism for performance.
hugomg 8y ago
Terra uses Lua as a metaprogramming language, while Pallene/Titan use Lua as a scripting language. Terra is designed for high performance numerical computing. As you mentioned, it has no garbage collector, uses C-like datatypes and its executables are completely detached from the Lua runtime. Pallene, on the other hand, is all about being able to seamlessly interoperate with Lua at run-time. It is possible to directly manipulate Lua tables and functions from a Pallene program. From the point of view of Lua, Pallene modules can be loaded as a C extension module would, except that Pallene is designed to integrate even better with Lua (sharing its garbage collector and having better C API performance). As the other commenter pointed out, we are currently compiling down to C. However, it is possible that we could switch to LLVM IR in the future.
eggy 8y ago
I had submitted this to HN because I was trying to evaluate using Terra instead of Zig [1] as my C replacement language. I had already become familiar with a particular dual-language environment called Extempore, [2] for livecoding that has a scheme language, and a c-like, s-expression-based language called xtlang that is compiled. You can mix the two in the same programming session, and it really works for me. And then I came upon Pallene. I like the idea of having a scripting language like Lua, but the clarity of a typed, compiled, non-GC language instead of C or the templates of C++. Terra ticks those boxes. The mix of Lua and Terra seems to be very flexible too from my early explorations. Is Pallene within an order of magnitude of the speed of Terra given no special tricks are needed to pull off a task. Are there any "bad" things Terra does that Pallene keeps within the better side of Lua. I guess I am asking if Pallene is a better fit for a dual-language system based on Lua than Terra other than maximum numerical computing performance. Thanks! [1] ziglang.org [2] https://extemporelang.github.io/
- hugomg 8y ago
  I talk a bit about this in a sibling comment. Maybe that helps answer your question? Pallene uses garbage collection, and shares the Lua garbage collector. The idea is to make as easy as possible to call Pallene from Lua and Lua from Pallene. Meanwhile, Terra only uses Lua at compilation time for metaprogramming and template building. At runtime, if you want to call Lua from Terra (or vice versa) you need to use the C API, just like you would do with C. I wouldn't really try to compare the performance of Pallene with Terra. They are two very different languages, doing different things.
  - eggy 8y ago
    Thank you for explaining it more to me. If I were just interested in numeric computing (arrays as well), I am assuming without benchmarking Terra and Pallene that Terra would win by an order of magnitude, no? Thanks again!
    - hugomg 8y ago
      If you were writing naive code, it probably wouldn't be that much. Maybe a 2to 3 times difference. But the thing with Terra is that you can be even faster than naively-written C if you know what you are doing.
      - eggy 8y ago
        I am trying to explore Terra more for this reason, but Pallene has piqued my interest. My guess from the responses and what the authors of Pallene have stated is that Terra is probably better to stick with for numerical work.
  - eslaught 8y ago
    I would just note, for anyone else coming on this, that in Terra you can also call back into Lua. From an implementation perspective, sure it goes through the C API, but as far as users are concerned, it looks pretty much like a normal function call (except as of the 2016 release you have to cast the Lua function to a specific type, but I don't think this is a terribly big deal). The bigger issue is that as soon as you call from Terra back to Lua you've made a circular dependency, and so you can't then dump an object file and have it be entirely free of the Lua VM. This for me happens to be one of the big selling points of Terra, because I know that I can write as much code as I want and (usually) can still come out with clean object files to link into any old project on the other side. I definitely get the appeal of a system which is intended to integrate with the same VM. If it weren't for some of the constraints of my current project, I'd definitely be thinking about it, so I'm glad that people are putting effort into exploring both approaches.

nerpderp83 8y ago

They emit C and call out to the system C compiler. They bypass the normal Lua extension mechanism for performance.

hugomg 8y ago

Terra uses Lua as a metaprogramming language, while Pallene/Titan use Lua as a scripting language. Terra is designed for high performance numerical computing. As you mentioned, it has no garbage collector, uses C-like datatypes and its executables are completely detached from the Lua runtime. Pallene, on the other hand, is all about being able to seamlessly interoperate with Lua at run-time. It is possible to directly manipulate Lua tables and functions from a Pallene program. From the point of view of Lua, Pallene modules can be loaded as a C extension module would, except that Pallene is designed to integrate even better with Lua (sharing its garbage collector and having better C API performance). As the other commenter pointed out, we are currently compiling down to C. However, it is possible that we could switch to LLVM IR in the future.

eggy 8y ago

I had submitted this to HN because I was trying to evaluate using Terra instead of Zig [1] as my C replacement language. I had already become familiar with a particular dual-language environment called Extempore, [2] for livecoding that has a scheme language, and a c-like, s-expression-based language called xtlang that is compiled. You can mix the two in the same programming session, and it really works for me. And then I came upon Pallene. I like the idea of having a scripting language like Lua, but the clarity of a typed, compiled, non-GC language instead of C or the templates of C++. Terra ticks those boxes. The mix of Lua and Terra seems to be very flexible too from my early explorations. Is Pallene within an order of magnitude of the speed of Terra given no special tricks are needed to pull off a task. Are there any "bad" things Terra does that Pallene keeps within the better side of Lua. I guess I am asking if Pallene is a better fit for a dual-language system based on Lua than Terra other than maximum numerical computing performance. Thanks! [1] ziglang.org [2] https://extemporelang.github.io/

hugomg 8y ago
I talk a bit about this in a sibling comment. Maybe that helps answer your question? Pallene uses garbage collection, and shares the Lua garbage collector. The idea is to make as easy as possible to call Pallene from Lua and Lua from Pallene. Meanwhile, Terra only uses Lua at compilation time for metaprogramming and template building. At runtime, if you want to call Lua from Terra (or vice versa) you need to use the C API, just like you would do with C. I wouldn't really try to compare the performance of Pallene with Terra. They are two very different languages, doing different things.
- eggy 8y ago
  Thank you for explaining it more to me. If I were just interested in numeric computing (arrays as well), I am assuming without benchmarking Terra and Pallene that Terra would win by an order of magnitude, no? Thanks again!
  - hugomg 8y ago
    If you were writing naive code, it probably wouldn't be that much. Maybe a 2to 3 times difference. But the thing with Terra is that you can be even faster than naively-written C if you know what you are doing.
    - eggy 8y ago
      I am trying to explore Terra more for this reason, but Pallene has piqued my interest. My guess from the responses and what the authors of Pallene have stated is that Terra is probably better to stick with for numerical work.
- eslaught 8y ago
  I would just note, for anyone else coming on this, that in Terra you can also call back into Lua. From an implementation perspective, sure it goes through the C API, but as far as users are concerned, it looks pretty much like a normal function call (except as of the 2016 release you have to cast the Lua function to a specific type, but I don't think this is a terribly big deal). The bigger issue is that as soon as you call from Terra back to Lua you've made a circular dependency, and so you can't then dump an object file and have it be entirely free of the Lua VM. This for me happens to be one of the big selling points of Terra, because I know that I can write as much code as I want and (usually) can still come out with clean object files to link into any old project on the other side. I definitely get the appeal of a system which is intended to integrate with the same VM. If it weren't for some of the constraints of my current project, I'd definitely be thinking about it, so I'm glad that people are putting effort into exploring both approaches.