Greetings, I'm new to Template Haskell and am trying to work out some examples. I successfully used this function (makeSum n) to generate a function that takes n arguments. \begin{code} -- |Given a size, n and n expressions, sum them up, so: -- > $(makeSum 4) 1 2 3 10 -- => 16 -- > $(makeSum 4) 1.0 2.2 3.4 10.1 -- => 16.7 makeSum :: Int -> ExpQ makeSum n = lam aPats (sumExps aVars) where -- create the symbols we'll need: aPats ::[Pat] aVars ::[ExpQ] (aPats,aVars) = genPE "num" n sumExps :: [ExpQ] -> ExpQ sumExps (h:t) = [| $h + $(sumExps t) |] sumExps [] = [| 0 |] \end{code} Now I would like to bring a bunch of versions of this function into scope, something like

$(genSummers 10)

where genSummers :: Int -> Q [Dec] and brings into scope: makeSum0 :: Int ... makeSum2 :: Int -> Int -> Int ... makeSum10 :: ... So this seems to make sense:

genSummers n = returnQ [Fun ("makeSum" ++ (show i)) [Clause [] (Normal $(makeSum i)) [] ] | i <- [1..n] ]

But actually, I run into a stage restriction. Now I can create a function:

makeSumE :: Int -> Exp

and say:

genSummers n = returnQ [Fun ("makeSum" ++ (show i)) [Clause [] (Normal (makeSumE i)) [] ] | i <- [1..n] ]

But how to define makeSumE? I try this: \begin{code} makeSumE :: Int -> Exp makeSumE n = Lam aPats (sumExps aVars) where -- create the symbols we'll need: aPats ::[Pat] aVars ::[Exp] (aPats,aVars) = genPE' "num" n sumExps :: [Exp] -> Exp sumExps (h:t) = [| $h + $(sumExps t) |] --oops, can't do that sumExps [] = Lit $ Integer 0 \end{code} But alas, the commented line is not the right type. So how do I write genSummers? peace, isaac ps. I implemented the printf and sel examples from the paper with the real stuff from the GHC6 library, and that code can be found on the wiki: http://www.haskell.org/hawiki/TemplateHaskell Maybe when I come up with a handful of nice examples I can add them to the haddock for the Language.Haskell.THSyntax