Fellow Haskelleers, I'm pleased to announce the release of haskell-src-exts-1.1.4! * On hackage: http://hackage.haskell.org/package/haskell-src-exts * Via cabal: cabal install haskell-src-exts * Via darcs: darcs get http://code.haskell.org/haskell-src-exts * Report bugs: http://trac.haskell.org/haskell-src-exts haskell-src-exts is a package for Haskell source code manipulation. In particular it defines an abstract syntax tree representation, and a parser and pretty-printer to convert between this representation and String. It handles (almost) all syntactic extensions to the Haskell 98 standard implemented by GHC, and the parsing can be parametrised on what extensions to recognise. haskell-src-exts-1.1.4 follows version 1.1.3 in being a mostly experimental release. From a PVP perspective, the version number indicates that no incompatible changes have been made to the *stable* portion of the package, i.e. anything that doesn't contain Annotated in its module name. The experimental stuff in Language.Haskell.Annotated{.*} has changed quite a lot, but those of you who depend on it already must obviously know what you're doing. ;-) haskell-src-exts-1.1.4: =================== * For the stable part, the only new thing in haskell-src-exts-1.1.4 is a bug fix that allows declaration headers surrounded by parentheses to be parsed, e.g. "data (a :< b) = ...". * For the experimental part, the new and cool feature is a full exact-printer, allowing full round-tripping of parsing plus printing. In other words, using the parser and the exact-printer in conjunction gives the same result back: exactPrint . parse == id . (Well, that's half a lie since you need to use parseWithComments and some uncurrying if you want to so easily compose, but that's the gist of it anyway. :-)) * There have also been a number of further changes to the (annotated) AST to allow it to retain enough source information to allow for said exact-printing. In particular there have been changes to the way contexts and declaration heads are treated, and literals have been embellished to remember just how they were given (e.g. did we use 0xFF or 255? \BEL or \a?). * With a few small caveats, the round-tripping works over the full (alas somewhat small) test suite that comes with (the darcs version of) haskell-src-exts: - Trailing whitespace on a line is not retained. (The test suite uses reverse . dropWhile (isSpace) . reverse on each line to disregard that issue.) - Tab characters in the source are converted to (8) spaces (except when they appear inside comments or literals). (The test suite doesn't contain tabs.) - Exact specification of literals is only remembered for literals used as literals :-). What I mean is, source literals appearing in other positions in the source than as Haskell literals will be converted to a basic form. E.g. 'infixl 0x02 %%' will become 'infixl 2 %%'. Apart from infix declarations (tell me you never considered writing them that way!) this mostly matters for various pragmas. - Parentheses used around the function symbol in a function declaration will not be remembered (I can't figure out how to make a non-outrageous change to the AST to cope with them). E.g. '(foo a) b = ...' will be printed as 'foo a b = ...'. If anyone has an idea for a neat (or at least non-outrageous) AST fix that could handle these cases, drop me a line. - Literate source files are not handled by the exact-printer (can't re-literate them). Please, help me test this on your source code! If you grab a darcs version of the package from the repository, you can put any and all source files you want to test in the "haskell-src-exts/Test/examples" directory and then just run 'cabal test'. Please report any failing cases to my trac! :-) Cheers and Happy Haskelling, /Niklas