On Fri, Mar 26, 2010 at 5:56 AM, Andy Wingo <wi...@pobox.com> wrote: > http://www.gnu.org/software/guile/mail/mail.html :) Guile-devel. Send > things there, and copy me on them if you really want it to go to my > attention.
Ah, OK, I thought you meant the summer-of-c...@gnu.org mailing list. > Well, I've already heard of someone who would like to do Lua, so if it's > the same to you, I'd have a look at Python. Here's a mail I sent to the > list recently regarding practicalities: > > http://lists.gnu.org/archive/html/guile-devel/2010-03/msg00076.html > > I'd also have a look at Thomas Bushnell's early work at supporting > Python, before we had the compiler: http://savannah.gnu.org/projects/gpc > > I am somewhat concerned that we'll end up with a number of half-finished > language implementations. I'm not sure what to do or think about that. I'll probably apply to work on Python then. Two quick questions: 1. How fast would you need it to be? (i.e. am I going to be writing C code or can I stick with straight Scheme?) 2. I was thinking of compiling Python into Scheme code, but you suggest in that link compiling to Tree-IL instead. Could you elaborate on the logic behind that more? Does it just result in faster programs? > Hm, another thought, project-wise: have you heard of parsing expression > grammars before? Here are a couple links: > > http://en.wikipedia.org/wiki/Parsing_expression_grammar > http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html > > Writing a good PEG parser library, together with docs and example > grammars, sounds like about a 1.5-2 month project -- just about right > for the SOC. > > We do have a LALR parser generator; I said something else about it in > the mail to guile-devel. A PEG parser seems like a shorter project than two months, but maybe writing one that's up to GNU standards would take a while. Would you prefer this over a python compiler? I'd be up for it; I mostly want to be writing something intellectually interesting in Scheme. > > Happy hacking, > > Andy > -- > http://wingolog.org/ > Anyway, sorry I haven't written for the last 3 days. You said you wanted to see some code so I wrote some, but I kinda got caught up in it. I hosted things up at http://people.cs.uchicago.edu/~mlucy/ if you want to take a look. peg.scm is a PEG parser. It works on the things I've tested it on, but I'd be amazed if there weren't any bugs lurking there. It's also in need of a serious refactoring--please don't think my finished code looks like parse-expression. It works but I wouldn't consider it finished by any standard, I just ran out of time (applications open tomorrow). rvector.scm is a resizable vector library--not terribly useful, but I wrote it to get familiar with guile before writing peg.scm (and as evidence that I do, in fact, produce reasonably clean code once the bugs are ironed out). peg-tst.scm and rvector-tst.scm do what they sound like. peg-tst.scm is two tests and an example of the library actually parsing a simple function grammar. rvector-tst.scm won't complete successfully without the change I suggested in http://lists.gnu.org/archive/html/bug-guile/2010-03/msg00011.html. (Nobody wrote back so I'm not entirely sure it's a bug. If it isn't then rvector-tst.scm is wrong.)
