tor 2002-10-17 klockan 17.32 skrev Simon Marlow:

Note that Happy has support for some Haskellish things which you won't get if you use bison to generate Haskell. For example: type signatures on productions, and support for threading a monad around the parser.

Another feature which I would love to have in Happy is support for more EBNF stuff, like repetition and alternative. Repetition maps to Haskell lists and alternative maps to haskell Maybe. Since there exists a transformation from EBNF to BNF this should be possible. Also, the transformation can take certain things into account, like that parsing a list of things is best done like this (due to the parser being LALR) list_of_things ::= empty | list_of_things thing instead of this more natural way list_of_things empty | thing list_of_things Regards, Martin