Hello everybody, I wrote me this nice function 'buildRns' which splices in $(varP w) nice and recursively. Unfortunately, this only seems to work in the 7.8 branch, not in 7.6.3. Is this indeed new, or am I missing something obvious? The message is: ADP/Fusion/TH.hs:106:86: Parse error in pattern: $(varP w) The code works wonderfully in 7.8. It not only compiles, but also produces working code in applications. I have no problem waiting until 7.8 is stable, but being backwards compatible to 7.6 would be nice. Many thanks, Christian buildRns f xs [] = appE ([| return . SM.singleton |]) (foldl (\g z -> appE g (varE z)) (return f) xs) buildRns f xs (VarP v : ys) = buildRns f (xs++[v]) ys buildRns f xs (TupP [_,VarP v] : ys) = do w <- newName "w" [| $(varE v) >>= return . SM.concatMapM (\ $(varP w) -> $(buildRns f (xs++[w]) ys)) |] -->>>>> ^^^^^^^^^