Let me preface my comments by saying that I mean them constructively, not negatively.
One big problem is this project has little relevance to the world outside arclanguage.org.
On the technical side, I'd suggest looking to see if anyone has made a Scheme to Common Lisp compiler, since that's an isomorphic problem. If one exists, that will give you a big start. If one doesn't exist, hmmm....
Offhand, I don't see how you're going to handle continuations or tail recursion. Note that many Scheme implementations punt on continuations (e.g. Kawa, Scheme 48, QScheme). Nil handling is also likely to be a pain.
If you're looking for a way to compile Arc, I think it would be much easier to use an existing Scheme compiler as the base, rather than using a Common Lisp compiler. Using a Common Lisp compiler seems to be just adding difficulty.
On the other hand, you have a lot of time budgeted to get the web server running. It seems to me that if you get Arc running, then srv.arc should just work and give you the web server for free.
I think interpreting Arc (as opposed to compiling) in Common Lisp using Peter Norvig's Scheme interpreter is doable, and I'm actually currently looking into that.
Thanks. I appreciate the constructive criticism :)
> This project has little relevance to the world outside arclanguage.org.
I don't see how much of anything I do here affects the outside world.
> I'd suggest looking to see if anyone has made a Scheme to Common Lisp compiler.
That seems like a rather roundabout method of compiling Arc to CL. Should we always use existing cross language compilers whenever we want to port Arc to a new language?
Say we have a language X, which only has a CL to X compiler. Compiling is then a conversion from Arc to Scheme, then to CL and finally to X. Is it really a good thing to have all the middlemen? And say we have a language Y which only has a X to Y compiler....
> I don't see how you're going to handle continuations or tail recursion.
Continuations are a difficulty, but I think one of CL's libraries may do the trick. They might not be truly first-class, but if they work I don't intend on worrying about it until I've got everything else working.
I don't see how tail recursion would be a problem. As far as I know most CL implementations provide tail recursion. (pg's ANSI Common Lisp talks a lot about using tail recursion in CL, which is one reason why I am not too worried about it.)
> It seems to me that if you get Arc running, then srv.arc should just work and give you the web server for free.
I hope it works out that way. (I will be more than happy to move on to other things if that step goes quickly.)
In my previous posting, I didn't mean to use the Scheme layer as a middleman; I meant to take an existing Scheme compiler and do s/lambda/fn/g on the code (as well as other necessary changes :-) to end up with an Arc compiler.
If you're implementing a Scheme-like system, I highly recommend Dybvig's "Three Implementation Models for Scheme" (http://www.cs.indiana.edu/~dyb/pubs/3imp.pdf). The three models are a heap model, a stack model, and implementation on a crazy string-based research processor; you'd probably want the stack model. Despite being a PhD thesis, it is very practical; it describes how the author implemented Chez Scheme and gives a pretty much full Scheme implementation running on a simple virtual machine. It handwaves about converting the virtual machine code to assembly, and gives some sample VAX code in an appendix.
I'll reiterate that you should look at how to make your project have a larger impact and relevance; what could you do (perhaps using your compiler as a base) that 1000 people would benefit from?
So basically you propose writing a meta-circular Arc compiler by porting a Scheme compiler to Arc, and modifying the compiler to compile Arc instead? That actually sounds like a really cool idea, if I understand you correctly. But what Scheme compiler would you use as a base?
I presume the paper you posted is meant for implementing Scheme from scratch? (So this would be an alternative to the previous option?) I'll look over it if I get the time.
Now perhaps I'll see if I can make a proposal out of this. (I might as well, assuming I have the time, since I am allowed more than one.) Although there is one issue: in order for such a proposal to get funded, I need someone from the Arc community to step up and mentor it.
