haskell-mode indents parallel list comprehensions (the GHC extension)
just fine, but it seems to have trouble with non-parallel ones.  For
instance, consider this code fragment:

allCards :: CardUniverse -> [CardValue]
allCards (CardUniverse s free) = free ++ suited
    where suited = [cv | suit <- s,
                         (cv, _) <- elems (suitCards suit)]

  haskell-mode wants me to indent the last line to either the level of
"s" or the level of "cv" in the previous line; for instance: