Re: Haskell Parser in Hugs
[EMAIL PROTECTED] (Martin Erwig) wrote, I am wondering what is the best way (in terms of easy-to-use and easy-to-install) to use a parser for Haskell in Hugs. As far as I know the parsers by Sven Panne and Manuel Chakravarty require ghc. I didn't write a parser for parsing Haskell - I only wrote a parser and lexer library for writing parsers in Haskell. Sven and Sigbjorn(?)'s parser is not complete yet, as far as I know. Unfortunately, infix declarations etc make it quite a hassle to write a parser for Haskell and to be honest, I doubt that you get it to work in Hugs with reasonable efficiency (maybe if you carefully hand code it)[1] - a Happy-generated parser will definitely get too big. However, what may be interesting is that Roman Lechtchinsky [EMAIL PROTECTED] is currently implementing a parser for at least a subset of Haskell using my libraries[2]. While he is working with GHC, there is nothing fundamental, I believe, which would prevent you from using his code in Hugs (apart from maybe the efficiency)[3]. The parser library needs one non-standard feature (existential type variables), but you have this in GHC and Hugs. In any case, wouldn't it be a good idea to include with each Haskell implementation a module "AST" that defines a representation of Haskell programs and offers functions like "parse" and "print"? Would be cool. Ideal would be a whole meta-programming library, but its a lot of work, I believe. Cheers, Manuel PS: If anybody ever needs a parser for C implemented in Haskell, that's something where I could help out. [1] "With reasonble efficiency" here means taking less than 5 minutes for a 10 line program (if you manage not to run out of memory, that is). [2] shameless plug There is now a paper on the self-optimising lexer library at http://www.score.is.tsukuba.ac.jp/~chak/papers/Cha99.html /shameless plug [3] The whole Compiler Toolkit tries to be as portable as possible, which means all system-dependent code is located in a single module and only uses features, which I expect - in one way or another - to be available in any Haskell system.
Re: Haskell Parser in Hugs
Simon Marlow wrote: [EMAIL PROTECTED] (Martin Erwig) wrote, I am wondering what is the best way (in terms of easy-to-use and easy-to-install) to use a parser for Haskell in Hugs. [...] Our Haskell parser library works fine with Hugs: [...] It's not quite complete (it doesn't do fixity resolution, for example), it'll probably do what you want. This parser was the prequel to GHC's new Happy-based parser. A possible route to get a "real-world" (i.e. well debugged and complete H98) module AST would be: * Throw all files needed by GHC's parser together in a subdir. * Remove everything GHC-specific, e.g. lexing the .hi stuff. * Track changes to the relevant sources in the CVS in AST. This should be very tedious, because those parts of GHC are quite stable by now. The only tricky point is dealing correctly with infix ops in the presence of the module system. Any *easy* suggestions for this? Perhaps if I have some spare time... (Hmmm, not very probable at the moment, the weather in Munich is too nice... :-) But I wouldn't mind if somebody else volunteered. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 mailto:[EMAIL PROTECTED]D-80538 Muenchen http://www.informatik.uni-muenchen.de/~Sven.Panne
Re: Haskell Parser in Hugs
"Martin" == Martin Erwig [EMAIL PROTECTED] writes: Martin I am wondering what is the best way (in terms of Martin easy-to-use and easy-to-install) to use a parser Martin for Haskell in Hugs. As far as I know the parsers Martin by Sven Panne and Manuel Chakravarty require ghc. There is also `lucky`, a parser generator using parser combinators. It's compatible with happy 0.9, but the resulting parsers are much smaller. A `lucky` file for Haskell 1.3 is available (it's part of Norbert Kloses masters thesis). You can find it in http://www.ki.informatik.uni-frankfurt.de/persons/marko/marko.html Marko
Re: Haskell Parser in Hugs
I am wondering what is the best way (in terms of easy-to-use and easy-to-install) to use a parser for Haskell in Hugs. As far as I know the parsers by Sven Panne and Manuel Chakravarty require ghc. You could try using the parser from nhc98, written using space-efficient parser combinators. ftp://ftp.cs.york.ac.uk/pub/haskell/parsepp I have stripped out almost everything except the parser and pretty-printer (this one should really be called an ugly-printer). See the README, and Main.hs. Regards, Malcolm P.S. With the help of dependencies generated automatically by hmake, creating and testing this package with hugs took about 15 minutes.
