Hi Paul, During my internship I developed a GLR parser generator and a grammar interpreter fully in Haskell, in a tool called HaGLR; You'll find documentation on the tool at: http://wiki.di.uminho.pt/twiki/bin/view/Research/PURe/HaGLR The tool is available as part of the UMinho Haskell libraries at: http://wiki.di.uminho.pt/twiki/bin/view/Research/PURe/PUReSoftware I have to say that the tool was maintained until 2005/2006, but that, unfortunately, not any more; Anyway, the tool itself consisted of very simple Haskell code, so it should easily be updated/altered; Hope it helps! Joao -- João Paulo Fernandes Universidade do Minho www.di.uminho.pt/~jpaulo Em 2010/06/02, às 11:55, Paul Jensen escreveu:

[Apologies if this is the wrong place to ask -- there appears to be no Happy-specific list.]

I'm interested in experimenting with using a GLR parser to parse some data that could be interpreted in different ways. I'm trying to use Happy's GLR mode but I am encountering an error building one of the examples (specifically http://darcs.haskell.org/happy/examples/glr/expr-eval/Expr.y):

[Mac OS X 10.6.3]

rhoda:expr-eval psj$ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.12.1

rhoda:expr-eval psj$ happy --version Happy Version 1.18.4 Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow

rhoda:expr-eval psj$ happy --glr --ghc Expr.y shift/reduce conflicts: 9 happy: src/ProduceGLRCode.lhs:190:11-76: Irrefutable pattern failed for pattern (pre, drop_me : post)

It's the same error someone else encountered last year, described at http://www.haskell.org/pipermail/haskell-cafe/2009-July/063770.html .

Does anyone have any insights into this? If Happy's GLR support isn't working just now, are there any other parser generators that produce GLR parsers that anyone would recommend having a look at?

Many thanks, psj _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe