I hope I chose proper mailing list, if not I apologize. And thanks for reading this!

I run into a problem with HStringTemplate (http://hackage.haskell.org/package/HStringTemplate) that I have never seen before.

Code, similar to

{-# LANGUAGE OverloadedStrings, DeriveDataTypeable, NoImplicitPrelude #-}
module Main where
import Data.Data
import qualified Data.Text as T
import qualified Text.StringTemplate as Template

renderTextTemplate :: (Template.ToSElem a) => T.Text -> a -> IO T.Text
renderTextTemplate name input = do
  templatesGroup <- Template.directoryGroup "templates"
  case Template.getStringTemplate (T.unpack name) templatesGroup of
    Nothing -> return $ "Internal Error: template '" `mappend` name `mappend` "' can not be rendered"
    Just template  -> return $ Template.render (Template.setAttribute "it" input (template:: Template.StringTemplate T.Text))

data Foo = Foo {value:: T.Text} deriving (Data, Typeable)

main :: IO ()
main = do
  content <- renderTextTemplate "test" $ Foo {value = "oh hi there!"}
  putStrLn content

with a simple template like this:
Just a test $it.value$!