showNamedStacks (P (P (valToText -> Just name) stack) ns') =
    showString name . 
    showString ": " . shows (stackCount stack) . 
    showChar '\n' . showNamedStacks ns'
showNamedStacks (P (P (valToText -> Just name) stack) ns') =
    showString name . 
    showString ": " . shows (stackCount stack) . 
    showChar '\n' . showNamedStacks ns'
showNamedStacks (P (P (valToText -> Just name) stack) ns') =
    showString name . 
    showString ": " . shows (stackCount stack) . 
    showChar '\n' . showNamedStacks ns'