Data.Option
data Option a
data OptionT m a
runOptionTDef
class ToOptionT t
noneIf
fromOption
isSome
isNone
optionToMaybe
maybeToOption
optionToList
optionToSL
listToOption
getSomeNote
option
catOptions
mapOption
forOptionM
mapOptionM
safeFromSome
failToOption
optionToFail
optionToFailT