On 05/25/2012 21:46, Antoine Latter wrote: > On Fri, May 25, 2012 at 2:51 PM, Sam Lindley <sam.lind...@ed.ac.uk> wrote: >> Template Haskell supports antiquotation for built-in quasiquotes, e.g.: >> >> [| \x -> x + $([|3 * 4|]) |] >> >> However, as far as I can tell, there is no way of supporting antiquotation >> in user-defined quasiquoters, because the only way to specify a new >> quasiquoter is through a quoteExp function of type String -> Q Exp. Of >> course, it is perfectly possible to write a parser for some fragment of >> Haskell inside your quoteExp function, but that seems crazy given that >> Template Haskell or rather GHC already implements a parser for the whole >> language. >> >> I know about Language.Haskell.Exts.Parser in haskell-src-exts, which >> provides parseExp :: String -> ParseResult Exp, but that Exp is a different >> type to the one provided by Template >> Haskell.<http://hackage.haskell.org/packages/archive/haskell-src-exts/1.9.0/doc/html/Language-Haskell-Exts-Syntax.html#t:Exp> >> I'm also aware of Dominic Orchard's syntax-trees package, which supports >> converting between the two representations using a cunning hack that >> pretty-prints the haskell-src-exts representation to a string and uses >> Template Haskell to parse it back. >> >> Is there a saner way of simulating antiquotation in user-defined >> quasiquoters? >> > > Have you looked at: > > http://hackage.haskell.org/package/haskell-src-exts-qq > http://hackage.haskell.org/package/haskell-src-meta > > The might help you pull something together. > > > Antoine > >> Sam
I use haskell-src-meta in language-c-quote (also on hackage) to support antiquotation and heartily endorse it. I have not used haskell-src-exts-qq. Geoff _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe