(sorry, forgot the subject on my first post) In the following code which uses template haskell, how can I get back the macro-expanded code generated from $(inferStartState ''MyState) I *can* recover the macro-expanded code for $(cnst 1 "x") using a debugging technique bulat describes on his tutorial at http://www.haskell.org/bz/th3.htm You can see what's going on in the function debugTemplates below. I'm trying to do this actually, to better understand how HAppS deals with state. It's a bit opaque now since the example on the tutorial uses TH. I think I would understand it better if I had code that didn't depend on TH. (MyState is from the happs tutorial at http://www.haskell.org/haskellwiki/HAppS_tutorial ) thanks! thomas. {-# OPTIONS -fglasgow-exts -fth #-} module MyState where import HAppS import HAppS.Protocols.SimpleHTTP2 import Data.Monoid import Data.Typeable import Control.Monad.State (get, put) import Language.Haskell.TH import Language.Haskell.TH.Syntax data MyState = MySt { appVal :: Int } deriving (Read, Show, Typeable) instance Serialize MyState where encodeStringM = defaultEncodeStringM decodeStringM = defaultDecodeStringM instance Monoid MyState where mempty = MySt 0 mappend (MySt x) (MySt y) = MySt (x+y) -- in ghci... -fth, :m + -- ghci... :t (inferStartState ''MyState) :: (Quasi m) => m [Dec] $(inferStartState ''MyState) -- boilerplate that will eventually be SYB -- ghci... :t cnst 1 "x" :: (Monad m) => m Exp cnst n s = return (LamE (replicate n WildP) (LitE (StringL s))) dumpSplice splice = runQ splice >>= putStrLn . pprint debugTemplates = do dumpSplice (cnst 1 "x") dumpSplice (inferStartState ''MyState) {- *MyState> debugTemplates \_ -> "x" Template Haskell error: Can't do `reify' in the IO monad *** Exception: user error (Template Haskell failure) -} --- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe --- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden.