Function to optimize tapping lands in MTG based on other cards you might want to cast

Mana.purs

data ManaSymbol
  = Generic
  | Specific SpecificMana
  | Split ManaColor ManaColor

data SpecificMana = Colorless | Colored ManaColor

data ManaColor = W | U | R | B | G

newtype Land = Land (List SpecificMana)

newtype Card = Card (List ManaSymbol)

newtype Hand = Hand (List Card)

-- Given the following:
--  - a `Card` to be cast
--  - a `Hand` of other cards that are available
--  - a `List` of `Land` cards that you are able to tap
-- Return a `List` of `Land` cards to be tapped in order to produce the needed
-- mana to to cast the `Card` or `Nil` if the card can't be cast. Optimize the
-- mana-tapping so that the greatest number of other cards in hand can be cast.
bestLandTap :: Card -> Hand -> List Land -> List Land
bestLandTap (Card cardSymbols) (Hand otherCards) lands =
  -- So, clearly this doesn't do anything. I'm also realizing that lands with
  -- activated abilities (e.g. manlands) should be treated specially. Also,
  -- this function should know about available mana from non-land sources.
  Nil -- TODO!