Copyright	2009-2015 Edward Kmett
License	BSD3
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	portable
Safe Haskell	Safe
Language	Haskell98

Data.Tagged

Contents

Tagged values
Conversion
Proxy methods GHC dropped

Description

Synopsis

newtype Tagged s b = Tagged {
- unTagged :: b
}
retag :: Tagged s b -> Tagged t b
untag :: Tagged s b -> b
tagSelf :: a -> Tagged a a
untagSelf :: Tagged a a -> a
asTaggedTypeOf :: s -> tagged s b -> s
witness :: Tagged a b -> a -> b
proxy :: Tagged s a -> proxy s -> a
unproxy :: (Proxy s -> a) -> Tagged s a
tagWith :: proxy s -> a -> Tagged s a
reproxy :: proxy a -> Proxy b

Tagged values

newtype Tagged s b Source #

A Tagged s b value is a value b with an attached phantom type s. This can be used in place of the more traditional but less safe idiom of passing in an undefined value with the type, because unlike an (s -> b), a Tagged s b can't try to use the argument s as a real value.

Moreover, you don't have to rely on the compiler to inline away the extra argument, because the newtype is "free"

Tagged has kind k -> * -> * if the compiler supports PolyKinds, therefore there is an extra k showing in the instance haddocks that may cause confusion.

Constructors

Tagged
Fields unTagged :: b

Instances

Bitraversable (Tagged :: * -> * -> *) Source #
Instance details Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Tagged a b -> f (Tagged c d) #
Bifoldable (Tagged :: * -> * -> *) Source #
Instance details Methods bifold :: Monoid m => Tagged m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Tagged a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Tagged a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Tagged a b -> c #
Bifunctor (Tagged :: * -> * -> *) Source #
Instance details Methods bimap :: (a -> b) -> (c -> d) -> Tagged a c -> Tagged b d # first :: (a -> b) -> Tagged a c -> Tagged b c # second :: (b -> c) -> Tagged a b -> Tagged a c #
Eq2 (Tagged :: * -> * -> *) Source #
Instance details Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Tagged a c -> Tagged b d -> Bool #
Ord2 (Tagged :: * -> * -> *) Source #
Instance details Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Tagged a c -> Tagged b d -> Ordering #
Read2 (Tagged :: * -> * -> *) Source #
Instance details Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Tagged a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Tagged a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Tagged a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Tagged a b] #
Show2 (Tagged :: * -> * -> *) Source #
Instance details Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Tagged a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Tagged a b] -> ShowS #
Generic1 (Tagged s :: * -> *) Source #
Instance details Associated Types type Rep1 (Tagged s) :: k -> * # Methods from1 :: Tagged s a -> Rep1 (Tagged s) a # to1 :: Rep1 (Tagged s) a -> Tagged s a #
Monad (Tagged s) Source #
Instance details Methods (>>=) :: Tagged s a -> (a -> Tagged s b) -> Tagged s b # (>>) :: Tagged s a -> Tagged s b -> Tagged s b # return :: a -> Tagged s a # fail :: String -> Tagged s a #
Functor (Tagged s) Source #
Instance details Methods fmap :: (a -> b) -> Tagged s a -> Tagged s b # (<$) :: a -> Tagged s b -> Tagged s a #
Applicative (Tagged s) Source #
Instance details Methods pure :: a -> Tagged s a # (<>) :: Tagged s (a -> b) -> Tagged s a -> Tagged s b # liftA2 :: (a -> b -> c) -> Tagged s a -> Tagged s b -> Tagged s c # (>) :: Tagged s a -> Tagged s b -> Tagged s b # (<*) :: Tagged s a -> Tagged s b -> Tagged s a #
Foldable (Tagged s) Source #
Instance details Methods fold :: Monoid m => Tagged s m -> m # foldMap :: Monoid m => (a -> m) -> Tagged s a -> m # foldr :: (a -> b -> b) -> b -> Tagged s a -> b # foldr' :: (a -> b -> b) -> b -> Tagged s a -> b # foldl :: (b -> a -> b) -> b -> Tagged s a -> b # foldl' :: (b -> a -> b) -> b -> Tagged s a -> b # foldr1 :: (a -> a -> a) -> Tagged s a -> a # foldl1 :: (a -> a -> a) -> Tagged s a -> a # toList :: Tagged s a -> [a] # null :: Tagged s a -> Bool # length :: Tagged s a -> Int # elem :: Eq a => a -> Tagged s a -> Bool # maximum :: Ord a => Tagged s a -> a # minimum :: Ord a => Tagged s a -> a # sum :: Num a => Tagged s a -> a # product :: Num a => Tagged s a -> a #
Traversable (Tagged s) Source #
Instance details Methods traverse :: Applicative f => (a -> f b) -> Tagged s a -> f (Tagged s b) # sequenceA :: Applicative f => Tagged s (f a) -> f (Tagged s a) # mapM :: Monad m => (a -> m b) -> Tagged s a -> m (Tagged s b) # sequence :: Monad m => Tagged s (m a) -> m (Tagged s a) #
Eq1 (Tagged s) Source #
Instance details Methods liftEq :: (a -> b -> Bool) -> Tagged s a -> Tagged s b -> Bool #
Ord1 (Tagged s) Source #
Instance details Methods liftCompare :: (a -> b -> Ordering) -> Tagged s a -> Tagged s b -> Ordering #
Read1 (Tagged s) Source #
Instance details Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Tagged s a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Tagged s a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Tagged s a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Tagged s a] #
Show1 (Tagged s) Source #
Instance details Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Tagged s a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Tagged s a] -> ShowS #
Bounded b => Bounded (Tagged s b) Source #
Instance details Methods minBound :: Tagged s b # maxBound :: Tagged s b #
Enum a => Enum (Tagged s a) Source #
Instance details Methods succ :: Tagged s a -> Tagged s a # pred :: Tagged s a -> Tagged s a # toEnum :: Int -> Tagged s a # fromEnum :: Tagged s a -> Int # enumFrom :: Tagged s a -> [Tagged s a] # enumFromThen :: Tagged s a -> Tagged s a -> [Tagged s a] # enumFromTo :: Tagged s a -> Tagged s a -> [Tagged s a] # enumFromThenTo :: Tagged s a -> Tagged s a -> Tagged s a -> [Tagged s a] #
Eq b => Eq (Tagged s b) Source #
Instance details Methods (==) :: Tagged s b -> Tagged s b -> Bool # (/=) :: Tagged s b -> Tagged s b -> Bool #
Floating a => Floating (Tagged s a) Source #
Instance details Methods pi :: Tagged s a # exp :: Tagged s a -> Tagged s a # log :: Tagged s a -> Tagged s a # sqrt :: Tagged s a -> Tagged s a # (**) :: Tagged s a -> Tagged s a -> Tagged s a # logBase :: Tagged s a -> Tagged s a -> Tagged s a # sin :: Tagged s a -> Tagged s a # cos :: Tagged s a -> Tagged s a # tan :: Tagged s a -> Tagged s a # asin :: Tagged s a -> Tagged s a # acos :: Tagged s a -> Tagged s a # atan :: Tagged s a -> Tagged s a # sinh :: Tagged s a -> Tagged s a # cosh :: Tagged s a -> Tagged s a # tanh :: Tagged s a -> Tagged s a # asinh :: Tagged s a -> Tagged s a # acosh :: Tagged s a -> Tagged s a # atanh :: Tagged s a -> Tagged s a # log1p :: Tagged s a -> Tagged s a # expm1 :: Tagged s a -> Tagged s a # log1pexp :: Tagged s a -> Tagged s a # log1mexp :: Tagged s a -> Tagged s a #
Fractional a => Fractional (Tagged s a) Source #
Instance details Methods (/) :: Tagged s a -> Tagged s a -> Tagged s a # recip :: Tagged s a -> Tagged s a # fromRational :: Rational -> Tagged s a #
Integral a => Integral (Tagged s a) Source #
Instance details Methods quot :: Tagged s a -> Tagged s a -> Tagged s a # rem :: Tagged s a -> Tagged s a -> Tagged s a # div :: Tagged s a -> Tagged s a -> Tagged s a # mod :: Tagged s a -> Tagged s a -> Tagged s a # quotRem :: Tagged s a -> Tagged s a -> (Tagged s a, Tagged s a) # divMod :: Tagged s a -> Tagged s a -> (Tagged s a, Tagged s a) # toInteger :: Tagged s a -> Integer #
(Data s, Data b) => Data (Tagged s b) Source #
Instance details Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Tagged s b -> c (Tagged s b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Tagged s b) # toConstr :: Tagged s b -> Constr # dataTypeOf :: Tagged s b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Tagged s b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Tagged s b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Tagged s b -> Tagged s b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Tagged s b -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Tagged s b -> r # gmapQ :: (forall d. Data d => d -> u) -> Tagged s b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Tagged s b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Tagged s b -> m (Tagged s b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Tagged s b -> m (Tagged s b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Tagged s b -> m (Tagged s b) #
Num a => Num (Tagged s a) Source #
Instance details Methods (+) :: Tagged s a -> Tagged s a -> Tagged s a # (-) :: Tagged s a -> Tagged s a -> Tagged s a # (*) :: Tagged s a -> Tagged s a -> Tagged s a # negate :: Tagged s a -> Tagged s a # abs :: Tagged s a -> Tagged s a # signum :: Tagged s a -> Tagged s a # fromInteger :: Integer -> Tagged s a #
Ord b => Ord (Tagged s b) Source #
Instance details Methods compare :: Tagged s b -> Tagged s b -> Ordering # (<) :: Tagged s b -> Tagged s b -> Bool # (<=) :: Tagged s b -> Tagged s b -> Bool # (>) :: Tagged s b -> Tagged s b -> Bool # (>=) :: Tagged s b -> Tagged s b -> Bool # max :: Tagged s b -> Tagged s b -> Tagged s b # min :: Tagged s b -> Tagged s b -> Tagged s b #
Read b => Read (Tagged s b) Source #
Instance details Methods readsPrec :: Int -> ReadS (Tagged s b) # readList :: ReadS [Tagged s b] # readPrec :: ReadPrec (Tagged s b) # readListPrec :: ReadPrec [Tagged s b] #
Real a => Real (Tagged s a) Source #
Instance details Methods toRational :: Tagged s a -> Rational #
RealFloat a => RealFloat (Tagged s a) Source #
Instance details Methods floatRadix :: Tagged s a -> Integer # floatDigits :: Tagged s a -> Int # floatRange :: Tagged s a -> (Int, Int) # decodeFloat :: Tagged s a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Tagged s a # exponent :: Tagged s a -> Int # significand :: Tagged s a -> Tagged s a # scaleFloat :: Int -> Tagged s a -> Tagged s a # isNaN :: Tagged s a -> Bool # isInfinite :: Tagged s a -> Bool # isDenormalized :: Tagged s a -> Bool # isNegativeZero :: Tagged s a -> Bool # isIEEE :: Tagged s a -> Bool # atan2 :: Tagged s a -> Tagged s a -> Tagged s a #
RealFrac a => RealFrac (Tagged s a) Source #
Instance details Methods properFraction :: Integral b => Tagged s a -> (b, Tagged s a) # truncate :: Integral b => Tagged s a -> b # round :: Integral b => Tagged s a -> b # ceiling :: Integral b => Tagged s a -> b # floor :: Integral b => Tagged s a -> b #
Show b => Show (Tagged s b) Source #
Instance details Methods showsPrec :: Int -> Tagged s b -> ShowS # show :: Tagged s b -> String # showList :: [Tagged s b] -> ShowS #
Ix b => Ix (Tagged s b) Source #
Instance details Methods range :: (Tagged s b, Tagged s b) -> [Tagged s b] # index :: (Tagged s b, Tagged s b) -> Tagged s b -> Int # unsafeIndex :: (Tagged s b, Tagged s b) -> Tagged s b -> Int inRange :: (Tagged s b, Tagged s b) -> Tagged s b -> Bool # rangeSize :: (Tagged s b, Tagged s b) -> Int # unsafeRangeSize :: (Tagged s b, Tagged s b) -> Int
IsString a => IsString (Tagged s a) Source #
Instance details Methods fromString :: String -> Tagged s a #
Generic (Tagged s b) Source #
Instance details Associated Types type Rep (Tagged s b) :: * -> * # Methods from :: Tagged s b -> Rep (Tagged s b) x # to :: Rep (Tagged s b) x -> Tagged s b #
Semigroup a => Semigroup (Tagged s a) Source #
Instance details Methods (<>) :: Tagged s a -> Tagged s a -> Tagged s a # sconcat :: NonEmpty (Tagged s a) -> Tagged s a # stimes :: Integral b => b -> Tagged s a -> Tagged s a #
(Semigroup a, Monoid a) => Monoid (Tagged s a) Source #
Instance details Methods mempty :: Tagged s a # mappend :: Tagged s a -> Tagged s a -> Tagged s a # mconcat :: [Tagged s a] -> Tagged s a #
Storable a => Storable (Tagged s a) Source #
Instance details Methods sizeOf :: Tagged s a -> Int # alignment :: Tagged s a -> Int # peekElemOff :: Ptr (Tagged s a) -> Int -> IO (Tagged s a) # pokeElemOff :: Ptr (Tagged s a) -> Int -> Tagged s a -> IO () # peekByteOff :: Ptr b -> Int -> IO (Tagged s a) # pokeByteOff :: Ptr b -> Int -> Tagged s a -> IO () # peek :: Ptr (Tagged s a) -> IO (Tagged s a) # poke :: Ptr (Tagged s a) -> Tagged s a -> IO () #
Bits a => Bits (Tagged s a) Source #
Instance details Methods (.&.) :: Tagged s a -> Tagged s a -> Tagged s a # (.\|.) :: Tagged s a -> Tagged s a -> Tagged s a # xor :: Tagged s a -> Tagged s a -> Tagged s a # complement :: Tagged s a -> Tagged s a # shift :: Tagged s a -> Int -> Tagged s a # rotate :: Tagged s a -> Int -> Tagged s a # zeroBits :: Tagged s a # bit :: Int -> Tagged s a # setBit :: Tagged s a -> Int -> Tagged s a # clearBit :: Tagged s a -> Int -> Tagged s a # complementBit :: Tagged s a -> Int -> Tagged s a # testBit :: Tagged s a -> Int -> Bool # bitSizeMaybe :: Tagged s a -> Maybe Int # bitSize :: Tagged s a -> Int # isSigned :: Tagged s a -> Bool # shiftL :: Tagged s a -> Int -> Tagged s a # unsafeShiftL :: Tagged s a -> Int -> Tagged s a # shiftR :: Tagged s a -> Int -> Tagged s a # unsafeShiftR :: Tagged s a -> Int -> Tagged s a # rotateL :: Tagged s a -> Int -> Tagged s a # rotateR :: Tagged s a -> Int -> Tagged s a # popCount :: Tagged s a -> Int #
FiniteBits a => FiniteBits (Tagged s a) Source #
Instance details Methods finiteBitSize :: Tagged s a -> Int # countLeadingZeros :: Tagged s a -> Int # countTrailingZeros :: Tagged s a -> Int #
NFData b => NFData (Tagged s b) Source #
Instance details Methods rnf :: Tagged s b -> () #
type Rep1 (Tagged s :: * -> *) Source #
Instance details type Rep1 (Tagged s :: * -> *) = D1 (MetaData "Tagged" "Data.Tagged" "tagged-0.8.5-KZCg0OnZiAB2QKmctiBGrw" True) (C1 (MetaCons "Tagged" PrefixI True) (S1 (MetaSel (Just "unTagged") NoSourceUnpackedness NoSourceStrictness DecidedLazy) Par1))
type Rep (Tagged s b) Source #
Instance details type Rep (Tagged s b) = D1 (MetaData "Tagged" "Data.Tagged" "tagged-0.8.5-KZCg0OnZiAB2QKmctiBGrw" True) (C1 (MetaCons "Tagged" PrefixI True) (S1 (MetaSel (Just "unTagged") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 b)))

retag :: Tagged s b -> Tagged t b Source #

Some times you need to change the tag you have lying around. Idiomatic usage is to make a new combinator for the relationship between the tags that you want to enforce, and define that combinator using retag.

data Succ n
retagSucc :: Tagged n a -> Tagged (Succ n) a
retagSucc = retag

untag :: Tagged s b -> b Source #

Alias for unTagged

tagSelf :: a -> Tagged a a Source #

Tag a value with its own type.

untagSelf :: Tagged a a -> a Source #

untagSelf is a type-restricted version of untag.

asTaggedTypeOf :: s -> tagged s b -> s Source #

asTaggedTypeOf is a type-restricted version of const. It is usually used as an infix operator, and its typing forces its first argument (which is usually overloaded) to have the same type as the tag of the second.

witness :: Tagged a b -> a -> b Source #

Conversion

proxy :: Tagged s a -> proxy s -> a Source #

Convert from a Tagged representation to a representation based on a Proxy.

unproxy :: (Proxy s -> a) -> Tagged s a Source #

Convert from a representation based on a Proxy to a Tagged representation.

tagWith :: proxy s -> a -> Tagged s a Source #

Another way to convert a proxy to a tag.

Proxy methods GHC dropped

reproxy :: proxy a -> Proxy b Source #

Some times you need to change the proxy you have lying around. Idiomatic usage is to make a new combinator for the relationship between the proxies that you want to enforce, and define that combinator using reproxy.

data Succ n
reproxySucc :: proxy n -> Proxy (Succ n)
reproxySucc = reproxy