* Switch to a Cabal build system: you need a recent version of Cabal
(1.1.6 or later). If you have GHC 6.4.2, then you need to upgrade
Cabal before building Happy. GHC 6.6 is fine.
* New %error directive
* New production forms: {%% .. } and {%^ .. }
* Added Attribute Grammar support, by Robert Dockins
`yacc' for C. Like `yacc', it takes a file containing an annotated BNF
specification of a grammar and produces a Haskell module containing a
parser for the grammar.
Happy is flexible: you can have several Happy parsers in the same
program, and several entry points to a single grammar. Happy can work
in conjunction with a lexical analyser supplied by the user (either
hand-written or generated by another program), or it can parse a
stream of characters directly (but this isn't practical in most
cases).