Clojure implemented on top of Python

https://github.com/eigenhombre/PyClojure

by DanielRibeiro • 14 years ago

64 36 14 years ago

videoappeal2• 14 years ago

If complaining about the startup times of JVM then i believe a solution exists laready i.e. ClojureScript running on top of Node.Js be a better fit?

regularfry2• 14 years ago

Python is preinstalled on a lot of platforms. That might be relevant.

masklinn2• 14 years ago

> i believe [...] ClojureScript running on top of Node.Js be a better fit?

Why? Python is likely to be installed in far more environment than Node, and for scripting, Clj on top of Python provides the faster startup of Python interpreters without the callback spaghetti inherent to Node. Because even if Clojure(Script) handles functions better than Javascript (both in verbosity — fns are no more verbose than lets — and in its scoping handling) it's still callback spaghetti.

videoappeal2• 14 years ago

Why ClojureScript? because it is much closer to feature complete, tested, supported by the core team yada yada

nathell• 14 years ago

An insane idea: run this on top of CLPython on top of ABCL on top of the JVM.

mattdeboard• 14 years ago

Yeah and let's get it to compile down to XML!

bwarp• 14 years ago

I wouldn't even go there.

I worked on an ecommerce project in the early 00's which compiled a high level turing complete DSL (not that far from LISP TBH) to XML and then used a virtual machine written in Java to run the XML. I've never seen a language in which the compiler output was 2 orders of magnitude larger than the source code.

I really don't know how anyone came to the conclusion that any of that was a good idea.

I still have nightmares about that.

Lazare• 14 years ago

I know it's irrational, but I tend to avoid JVM languages after some bad past experiences. (Yes, I know, Java is great, and the JVM is vastly improved! I said it's irrational.)

On the other hand, I've been wanting to learn Clojure. It'd be nice to see this project mature.

lclarkmichalek• 14 years ago

Well the aim of this project seems to be to avoid the start up time of the JVM so clojure can be used for scripting.

fceccon• 14 years ago

You can use Clojurescript on top of Node.js to achieve that. I never tried it so I don't have first hand experience.

https://github.com/clojure/clojurescript/wiki

cabalamat• 14 years ago

And also to "make use of [Python's] extensive, 'batteries included' libraries"

That's what seems the real benefit of it to me. Maybe Python will become not just a language, but a platform, like JVM or CLR, supporting multiple languages.

kaonashi• 14 years ago

How does it accomplish that better than say, clojurescript+node?

darklajid• 14 years ago

I guess .Net [1] is no option either? Not sure if that stuff works on top of mono as well..

1: https://github.com/clojure/clojure-clr

ericmoritz• 14 years ago

I have that same irrational feeling about the JVM, I'll say this, go ahead and learn Clojure; it only slightly smells like the JVM.

burgerbrain• 14 years ago

To be fair, the JVM is why Clojure doesn't have TCO (and no, trampolines don't count).

sandGorgon2• 14 years ago

There is one big problem in projects like these - Clojure's packaging system is strongly tied to the java ecosystem.

packages written in pure clojure are also distributed as jars and the ecosystem is strongly dependent on maven.

djhworld• 14 years ago

Initially when I first saw this I thought "nice but...really?" then I read the blurb about writing scripts/automating system tasks and remembered the pain of the JVM startup.

Will definitely be keeping an eye on this.

andrewcooke2• 14 years ago

how does it implement clojure's lazy sequences? does it manage to map them to generators?

irahul2• 14 years ago

From a cursory glance at https://github.com/eigenhombre/PyClojure/blob/master/core.py it doesn't do anything with the lists yet, other than having a list class which stores the values.

As far as lazy goes, how does clojure does it? Thunks? The implementer can opt for thunks or generators(doesn't generator serve as an higher level abstraction to manually "thunk and force") as far as Python implementation goes.

andrewcooke2• 14 years ago

i have no idea how clojure is implemented, but i guess i always assumed that they were implemented as iterators.

steele3• 14 years ago

oh JVM startup time isn't that terrible, but this is cool.

irahul2• 14 years ago

JVM startup time is terrible, compared to the alternatives.

regularfry2• 14 years ago

Yes, it is. When I compare red-green-refactor cycles between Ruby and Clojure, and I've got sub-second turnaround in one and 5+seconds in the other, it's painfully bad.

steele3• 14 years ago

Sounds like you need a slice of cake.

pavelludiq• 14 years ago

Why reimplement all of clojure as an interpreter? Why not just rewrite the java parts in python and compile to bytecode? Honest question.

moonchrome• 14 years ago

Actually a better path would have been to hack on the ClojureScript compiler that compiles to JavaScript and fork it to compile to Python, most of the core stuff is implemented with ClojureScript primitives (like seq library, collections, atoms, etc.) so there would be substantially less work starting from there.

Symmetry• 14 years ago

Are you familiar with PyPy? It was originally just an exercise in implementing Python in Python, but then it was discovered that this led to some very interesting possibilities for JIT compilation, and after a lot of work PyPy is now much faster for most tasks than regular CPython.

The thing is, there's nothing about PyPy that says it has to be implementing Python itself, and recently here on Hacker News there was an article where someone was singing the praises PyPy as a way to implement the language he was developing. http://tratt.net/laurie/tech_articles/articles/fast_enough_v...

And it seems this person had come to the same realization.

EDIT: Oops, rereading I see I misunderstood something the README said, and he is only now considering using PyPy instead of CPython.

apgwoz• 14 years ago

While I appreciate the sentiment, Python isn't exactly the fastest language out there. But, if you have to do it, I'd suggest compiling to the Python AST and emitting bytecode.

lloeki• 14 years ago

Or restricting oneself to RPython and reap all the benefits of PyPy's JIT basically for free.

celebdor• 14 years ago

I was thinking of doing just that last weekend. I look forward to start soon and hopefully use some of the infrastructure/ideas of this python implementation.

postfuturist• 14 years ago

To solve the clojure script startup time: http://www.martiansoftware.com/nailgun/ "Nailgun is a client, protocol, and server for running Java programs from the command line without incurring the JVM startup overhead."

I only know about since vimclojure uses it (to good effect, so it obviously works fine with Clojure).

gtrak• 14 years ago

Also consider clojurescript on node.js, might be more worth the effort than a python implementation at this point.

sandGorgon2• 14 years ago

I wonder what happened to Shen (http://www.lambdassociates.org/Shen/newappeal.htm). From the blurb, This function set defined a Lisp that was much smaller than Common Lisp, in fact, much more like John McCarthy's Lisp 1.5 which is the distant ancestor of all subsequent Lisps.... I went further and suggested that this small Lisp could probably be mapped into many of the Lisp-like successors to Lisp like Python, Clojure and Javascript. This meant that because Qi was bootstrapped, these mappings could be used port Qi into other platforms"

Actually come to think of it, what ever happened to clojure-in-clojure [1] - that would have made implementing clojure on top of any VM, relatively trivial

[1] http://blog.n01se.net/?p=41

Clojure implemented on top of Python

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