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Pixie: A small fast, native lisp
- andrewchambers 12y agoI'm glad there will be something like clojure, only with semi sane start up times. (pypy based interpreters are still slow to start.)
- GuiA 12y agoWhat's magical about it?
- JoshTriplett 12y agoI'm wondering the same thing. I dug through the entire repository, and I didn't see any references to "magical" properties.
- andrewchambers 12y agoDid you look through the rpython codebase too? Thats where the real magic is.
- drtse4 12y agoThe magical lack of documentation?
- nsmartt 12y agoThere are 61 commits and only one contributor. This isn't a good complaint, and the snark makes it worse.
- fab13n 12y agoThe snark wasn't necessary indeed, and as an early-stage project, lacking documentation is understandable. As an HN post however, if you tease us with "magical features" in the title, I'd expect to have the magic shown to me in the linked page, or at the very least in the top comment. I shouldn't have to grok the sources to figure it out.
- emidln 12y agoSubmitter here, I went with name of project + github title rather than editorialize.
- drtse4 12y agoThanks, i already noticed the age of the project :). The ""complaint"" is obviously valid, i'd add at least half a page of examples to explain what it does and how to try it, just to increase the chance of contribution. No snarkiness was intended... but looks like it came out that way.
- nsmartt 12y agoI didn't take your use of “documentation” to be so loose, but I agree that it should have an explanation for the use of “magical” in the title. The author has since added an explanation.
- andrewchambers 12y agoDid you even read the readme? He clearly says hes changing a bunch of stuff and doesn't think outside people can contribute much yet.
- drtse4 12y agoNext time, don't hit reply.
- 616c 12y agoWell judging from the description, "native" actually means writing it in RPython (a "restricted" Python with types for use in the PyPy Project for static analysis and speeding things up[0]) and then compiling it down using PyPy (I am guessing on the second part). That could be neat, the HyLang people (Lisp written in vanilla CPython Python; I think no C extensions AFAIK). [0] http://pypy.readthedocs.org/en/latest/coding-guide.html#id1 http://pypy.readthedocs.org/en/latest/coding-guide.html#id1
- dTal 12y agoHy isn't a full Lisp interpreter in Python, it's an s-expression to Python AST parser, which means it does everything Python does (including C extensions) at essentially native speed anyway - you can even write RPython in it. If you ask me, full Python interop makes Hy the most practical s-expression language today.
- JasonFruit 12y agoOne problem with Hy for me is that it keeps Python scoping, either global or function; that doesn't feel natural to me in a Lisp, and it gets in my way. If it weren't for that and a few similar matters, I'd agree with you on Hy's practicality; as it is, I'd give my nod to Clojure.
- _halgari 12y agoAdded a few comments in the README about that.
- daveloyall 12y agoPixie implements its own virtual machine. Isn't that how all the tiny lisps do it? :) You know, maybe 'magic' simply sets the bar higher than the project is prepared to support. Consider 'clever'.
- andrewchambers 12y agoUmm, I don't think you understand fully what it is. it is using rpython which is a meta tracing jit. pretty magic if you read about it.
- ottbot 12y agoHave fun.
- nicklovescode 12y agoWould love some examples that showoff the benefits
- _halgari 12y agoI added a few comments to the README on that subject.
- gopalv 12y agoThis is a lisp engine written in python - RPython, to be precise. It literally compiles the lisp code into python bytecode, which is pretty neat - sort of like clojure is for the JVM. https://github.com/pixie-lang/pixie/blob/master/pixie/vm/compiler.py#L598 https://github.com/pixie-lang/pixie/blob/master/pixie/vm/com... Perhaps not magical, but I like the effort (though lisp-as-shell has to contend with emacs first).
- DasIch 12y agoIt compiles to bytecode but it doesn't compile to python bytecode. The bytecode used by pixie is custom and also interpreted by pixie itself[1]. [1]: https://github.com/pixie-lang/pixie/blob/master/pixie/vm/interpreter.py https://github.com/pixie-lang/pixie/blob/master/pixie/vm/int...
- srean 12y agoEver since RPython had been announced I have wanted generator support in RPython. TCO'ed coroutines would be even better. PyPy devs did not see much use of it for writing their Python interprator so they left it out, which is a pity. How so ever shiny and neat dynamic typing might be, I have had very little use of it in my own Python code. A situation where I absolutely must store values of different types in the same variable (that or bullet to the head) has not presented itself that often if ever. For me RPython would have been a fine enough replacement, except that I do like generators a lot. Given the prominence of inversion of control (via coroutines) as a feature, I assume it would have helped pixie implementation too.
- fijal 12y agoRPython is not a language for normal usage and mostly because e.g. error messages are obscure and hard to read. There is some basic support for generators these days, however, unless you're writing another language, we strongly encourage you don't use it.
- sedachv 12y ago> This is a lisp engine written in python - RPython, to be precise. So there is nothing "native" about it, and until we see this on http://benchmarksgame.alioth.debian.org/ http://benchmarksgame.alioth.debian.org/ no basis for calling it "fast."
- cryptolect 12y agoI'm happy to see that some new 'modern lisp on x' projects are taking design cues from Clojure (See Rhine and now Pixie).
- dTal 12y agoClojure's success, I believe, is due to retaining Java's semantics (preserving library compatibility) while overhauling its syntax. Fighting the semantics of your host language/VM just makes work and causes trouble. Therefore, if you want a "Clojure on Python" that preserves the benefits of the original, you need to give it Python semantics, not Java/Clojure's. Hylang is that project - it uses Clojure syntax where sensible, and is fully compatible with Python. https://groups.google.com/forum/#!topic/clojure-py-dev/HbeNEkIG23U https://groups.google.com/forum/#!topic/clojure-py-dev/HbeNE... http://hy.readthedocs.org/en/latest/ http://hy.readthedocs.org/en/latest/
- andrewchambers 12y agoOnly hylang has a lot of stupid limitations and problems like scope leakage.
- vosper 12y agoI'm completely unfamiliar with Hylang - could you please elaborate on its limitations?
- dTal 12y agoI take it you refer to your complaint here: https://github.com/hylang/hy/issues/543 https://github.com/hylang/hy/issues/543 Your problem is with Python, not Hy. Hy inherits the "stupid limitations" of Python, and not even all of those - for example, it does away with the statement/expression distinction, which means multiline lambdas (at last!). It's just Python with s-expressions. If you don't like it, you either don't like Python or don't like s-expressions.
- eddieplan9 12y agoThe author is the creator of clojure-py [1]. Pixie looks like a follow-up effort with strong influence from PyPy. The following post of his from over 2 years ago might provide some insight: https://groups.google.com/forum/#!topic/clojure-py-dev/Lmhd0VwwdgA https://groups.google.com/forum/#!topic/clojure-py-dev/Lmhd0... [1] https://news.ycombinator.com/item?id=3649883 https://news.ycombinator.com/item?id=3649883
- daGrevis 12y agoI love little languages like this one! Just look at the source — it's still so readable and easy to understand, and the size — I could read through it in an evening! It reminds me a bit of diy-lisp where you implemented Lisp in Python yourself! https://github.com/daGrevis/diy-lisp https://github.com/daGrevis/diy-lisp
- wtbob 12y agoIt looks cool enough, but I wish more of these modern Lisp implementations would ask to implement the Common Lisp standard rate than their own, informally-specified version of Lisp. Yeah, Common Lisp is not perfect, but it does have a lot of excellent ideas, and some of the bits which don't look excellent actually are (e.g. pathnames and logical pathnames).
- sklogic 12y agoCommon Lisp is too big for a typical application (e.g., embedded scripting engines, mataprogramming hosts, etc.). And it's a Lisp-2, which is quite a deterrent for many.
- lispm 12y agoDepends on what you mean by 'big'. Physically it is not too big for typical applications. 'mentally' it may be too big for some developers. After a while then greenspun's tenth rule kicks in... 'Common Lisp' also does not mean it needs the full language. Some applications use subsets.
- sklogic 12y agoBig is over 1000 pages of a spec.
- wtbob 12y agoI know folks used to say that Common Lisp was too big, comparing it to C or Pascal. But is it really big compared to, e.g., Python, JavaScript or Ruby? If anything, a common complaint now is that too little is standardised (which is true, but good portable libraries exist for most such things). And, as lispm notes, one can implement a subset of Common Lisp—all that's required is that one define the subset.
- sklogic 12y agoInterestingly, so far people preferred to implement dialects of Lisp-1 mostly. Not that many Common Lisp subsets or even Common Lisp-inspired languages around. I can only name Shen as one obvious exception from this rule.
- lsdafjklsd 12y agoNeat project, although I am struggling with getting it working. Looking forward to installation instructions.
- _halgari 12y agoAuthor of pixie here. The project is still pretty young (about a month old), so I'll use that to explain away the lack of binaries, documentation, examples, etc. I've been more focused on adding features than getting stuff ready for presenting to the public. As an example, we didn't even have stack traces until a day or two ago. That being said I'll try to answer any questions you may have. Thanks!
- sktatlo 12y agoThis is an amazing effort! Now to clojure compatibility. You can only gain by making it clojure compatible. What would be the possible reasons to diverge? Another one: what are your plans for namespaces and code packaging and distribution? What are your thoughts about a build system? I think the world doesn't need another build and package distribution system. Which one would you reuse?
- _halgari 12y agoI love clojure, let me make this clear. But there are certain aspects of the language that don't apply if you are writing a VM from scratch in RPython. If I could make multimethods dispatching on types as fast as protocols, what is the point of protocols? A great example of this is the (fn [& args]) bit. In Clojure, variadic parameters are passed in as a ISeq. In Pixie they are a vector (or an immutable array actually). This allowed me to tune the JIT quite a bit to allow it to remove the allocation of "args" completely. As well as allow for things like unrolling a reduce over the args. This stuff would have been much harder if the arguments were passed in as an ISeq. This is the whole reason why Pixie exists, instead of something like "clojure-on-rpython". Compatibility means constraining the feature set. And that's not something I want to do yet.
- emidln 12y agoIt might be interesting down the line to see if I couldn't target pixie using something like cljx (or actual feature expressions if they ever land in a mainline clojure release). This wouldn't necessarily require any effort on the part of my target, but still allow portability when it makes sense.
- duckingtest 12y ago>Math system is fully polymorphic Does it have fully polymorphic other basic functions, like setq, eql (or however they are named)? I guess not? Do you plan on introducing some parts of CLOS? Lack of OO integration in CL is one of its biggest drawback for me... for me CLOS was the most powerful thing in lisp, not macros (mostly because they are not dynamic).
- _halgari 12y agoCLOS has been on my list to research for some time now, and I haven't made a decision on it yet. The goal would be to get the JIT to remove the method lookup completely, and that might get a bit tricky depending on how complex the lookup code is, but it is the most open dynamic OO system I've seen, so it might just be worth it.