gistfile1.txt

-- Code:

data HdbcSnaplet = forall conn. IConnection conn => HdbcSnaplet {
    _iConn :: conn
  }

makeLens ''HdbcSnaplet

{-
Error:

[7 of 7] Compiling Snap.Snaplet.Hdbc ( src/Snap/Snaplet/Hdbc.hs, interpreted )
src/Snap/Snaplet/Hdbc.hs:1:1: Splicing declarations
    makeLens 'HdbcSnaplet
  ======>
    src/Snap/Snaplet/Hdbc.hs:27:1-22
    Snap.Snaplet.Hdbc.iConn ::
      Data.Lens.Common.Lens HdbcSnaplet conn[a879]
    Snap.Snaplet.Hdbc.iConn
      = Data.Lens.Common.lens
          _iConn (\ x[a87l] s[a87m] -> s[a87m] {_iConn = x[a87l]})

src/Snap/Snaplet/Hdbc.hs:27:1:
    Not in scope: type variable `conn[a879]'
-}