Kawa 2.0 Supports Scheme R7RS

First time accepted submitter Per Bothner (19354) writes "Kawa is a general-purpose Scheme-based programming language that runs on the Java platform. It combines the strengths of dynamic scripting languages (less boiler-plate, fast and easy start-up, a REPL, no required compilation step) with the strengths of traditional compiled languages (fast execution, static error detection, modularity, zero-overhead Java platform integration).

Version 2.0 was just released with many new features. Most notably is (almost) complete support for the latest Scheme specification, R7RS, which was ratified in late 2013. This LWN article contains a brief introduction to Kawa and why it is worth a look."

Comments

Traditional

[phantomfive]

the strengths of traditional compiled languages....zero-overhead Java platform integration

I never thought I'd hear someone say that Java integration is a traditional strength of compiled languages (especially for a dialect of a language invented in the 50s).

Re:Traditional

[Per Bothner]

"Something that I find strange is how fast kawa seems to be [even] in the repl." Note that Kawa does a full compilation (to bytecode), with all the optimizations, even in the repl. (Of course it only optimized one line/command at a time in that case.) The downside is that Kawa is a little fragile if you redefine things in the repl; hence I advise using the --no-inline option for the repl. It's on the list of things to work on when we get a chance.

Re:..that runs on the Java platform.

[DuckDodgers]

But that's the whole point. My employer does everything on the JVM for our production websites and testing. I can't get them to introduce PHP, Basic, Pascal, Ada, Perl, Haskell, OCaml, or Fortran for anything. I also can't get them to seriously consider CPython, native Ruby, SBCL (Lisp), or DrScheme.

But if I want to introduce JRuby, Jython, Scala, Groovy, Clojure, or Javascript (available in the JVM via Rhino in older versions of Java and via Nashorn in Java 7), I can get consideration.

So I suspect Kawa is an attempt to build a Scheme developers can use at work, for production, without convincing the CTO to scrap the existing JVM-based technology stack and starting over from square one. I wish them good luck. I haven't looked at Kawa yet, I'm still hoping to get my boss to look at Clojure. :)

Re:kawa

[Per Bothner]

The Kawa 0.1 interpreter from 1996 was written by Alex Milowski, who is indeed Polish-American.

I took it over in 1996, and re-wrote it as a compiler. At this point, I doubt any of Alex's code still exists. I'm Norwegian-American, and Kawa means nothing in Norwegian. Still, I saw no reason to change the name.

Re:R7RS?

[Trepidity]

Technically "The Revised Revised Revised Revised Revised Revised Revised Report on the Algorithmic Language Scheme".

Scheme was first specified in a 1975 report, which was revised in 1978. The 1978 report was called "The Revised Report on Scheme, A Dialect of Lisp". The next version of Scheme, in 1985, initiated the current trend, by naming itself, "The Revised Revised Report on the Algorithmic Language Scheme", or "R2RS" for short. Since then it functions as sort of a version number, so R3RS was the successor to R2RS, and so on. But from R3RS onward, nobody actually writes out the "Revised Revised..." part.

Re:R7RS?

[DeVilla]

Can I have my Grammar Nazi sticker now?

Oh. You almost had it.
It's "May I ...".

Obi-Wan told Luke...

[gavron]

It's like Old Ben Kenobi told young Luke Skywalker:

"If you're trying to run it on a JVM you've already lost to the darkside."

Star Wars Quotes (that never happened)

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