Binrep.Type.Magic

Magic numbers (also just magic): short constant bytestrings usually found at the top of a file, often used as an early sanity check.

There are two main flavors of magics:

• byte magics e.g. Zstandard: 28 B5 2F FD
• printable magics e.g. Ogg: 4F 67 67 53 -> OggS (in ASCII)

For byte magics, use type-level Natural lists. For printable magics, use Symbols (type-level strings).

Documentation

data Magic (a :: k)

A singleton data type representing a "magic number" via a phantom type.

The phantom type variable unambiguously defines a constant bytestring. A handful of types are supported for using magics conveniently, e.g. for pure ASCII magics, you may use a Symbol type-level string.

Constructors

Magic

Instances

IsCBLen (Magic a :: Type)

The byte length of a magic is known at compile time.

Defined in Binrep.Type.Magic

Associated Types

type CBLen (Magic a) :: Natural

(Typeable a, Typeable k) => Data (Magic a)

Defined in Binrep.Type.Magic

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Magic a -> c (Magic a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Magic a)

toConstr :: Magic a -> Constr

dataTypeOf :: Magic a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Magic a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Magic a))

gmapT :: (forall b. Data b => b -> b) -> Magic a -> Magic a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Magic a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Magic a -> r

gmapQ :: (forall d. Data d => d -> u) -> Magic a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Magic a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Magic a -> m (Magic a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Magic a -> m (Magic a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Magic a -> m (Magic a)

Generic (Magic a)

Defined in Binrep.Type.Magic

Associated Types

type Rep (Magic a) :: Type -> Type

Methods

from :: Magic a -> Rep (Magic a) x

to :: Rep (Magic a) x -> Magic a

Show (Magic a)

Defined in Binrep.Type.Magic

Methods

showsPrec :: Int -> Magic a -> ShowS

show :: Magic a -> String

showList :: [Magic a] -> ShowS

KnownNat (Length (MagicBytes a)) => BLen (Magic a)

The byte length of a magic is obtained via reifying.

Defined in Binrep.Type.Magic

Methods

blen :: Magic a -> Int

(bs ~ MagicBytes a, ParseReifyBytesW64 bs, ReifyBytesW64 bs, KnownNat (Length bs)) => Get (Magic a)

Defined in Binrep.Type.Magic

Methods

get :: Getter (Magic a)

(bs ~ MagicBytes a, ParseReifyBytesW64 bs, ReifyBytesW64 bs, KnownNat (Length bs)) => GetC (Magic a)

Defined in Binrep.Type.Magic

Methods

getC :: GetterC (Magic a)

(bs ~ MagicBytes a, ReifyBytesW64 bs, KnownNat (Length bs)) => Put (Magic a)

Defined in Binrep.Type.Magic

Methods

put :: Magic a -> Putter

(bs ~ MagicBytes a, ReifyBytesW64 bs) => PutC (Magic a)

Defined in Binrep.Type.Magic

Methods

putC :: Magic a -> PutterC

Eq (Magic a)

Defined in Binrep.Type.Magic

Methods

(==) :: Magic a -> Magic a -> Bool

(/=) :: Magic a -> Magic a -> Bool

Strengthen (Magic a)

Strengthen the unit to some Magic a.

Defined in Binrep.Type.Magic

Methods

strengthen :: Weak (Magic a) -> Result (Magic a)

Weaken (Magic a)

Weaken a Magic a to the unit.

Defined in Binrep.Type.Magic

Associated Types

type Weak (Magic a)

Methods

weaken :: Magic a -> Weak (Magic a)

type CBLen (Magic a :: Type)

Defined in Binrep.Type.Magic

type CBLen (Magic a :: Type) = Length (MagicBytes a)

type Rep (Magic a)

Defined in Binrep.Type.Magic

type Rep (Magic a) = D1 ('MetaData "Magic" "Binrep.Type.Magic" "binrep-0.8.0-inplace" 'False) (C1 ('MetaCons "Magic" 'PrefixI 'False) (U1 :: Type -> Type))

type Weak (Magic a)

Defined in Binrep.Type.Magic

type Weak (Magic a) = ()

class Magical (a :: k)

Types which define a magic value.

Associated Types

type MagicBytes a :: [Natural]

How to turn the type into a list of bytes.

Instances

Magical (sym :: Symbol)

Type-level symbols are converted to UTF-8.

Defined in Binrep.Type.Magic

Associated Types

type MagicBytes sym :: [Natural]

Magical (ns :: [Natural])

Type-level naturals go as-is. (Make sure you don't go over 255, though!)

Defined in Binrep.Type.Magic

Associated Types

type MagicBytes ns :: [Natural]

type family Length (a :: [k]) :: Natural where ...

The length of a type-level list.

Equations

Length '[] = 0

Length (a ': as) = 1 + Length as