Binrep.CBLen

Documentation

class IsCBLen a

Associated Types

type CBLen a :: Natural

Instances

IsCBLen Int16

Defined in Binrep.CBLen

Associated Types

type CBLen Int16 :: Natural

IsCBLen Int32

Defined in Binrep.CBLen

Associated Types

type CBLen Int32 :: Natural

IsCBLen Int64

Defined in Binrep.CBLen

Associated Types

type CBLen Int64 :: Natural

IsCBLen Int8

Defined in Binrep.CBLen

Associated Types

type CBLen Int8 :: Natural

IsCBLen Word16

Defined in Binrep.CBLen

Associated Types

type CBLen Word16 :: Natural

IsCBLen Word32

Defined in Binrep.CBLen

Associated Types

type CBLen Word32 :: Natural

IsCBLen Word64

Defined in Binrep.CBLen

Associated Types

type CBLen Word64 :: Natural

IsCBLen Word8

Defined in Binrep.CBLen

Associated Types

type CBLen Word8 :: Natural

IsCBLen DMagic

Defined in Binrep.Test

Associated Types

type CBLen DMagic :: Natural

IsCBLen DStruct

Defined in Binrep.Test

Associated Types

type CBLen DStruct :: Natural

IsCBLen ()

Defined in Binrep.CBLen

Associated Types

type CBLen () :: Natural

Generic a => IsCBLen (GenericallyNonSum a :: Type)

Deriving via this instance necessitates UndecidableInstances.

Defined in Binrep.CBLen

Associated Types

type CBLen (GenericallyNonSum a) :: Natural

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

IsCBLen (NullPadded n a :: Type)

Defined in Binrep.Type.NullPadded

Associated Types

type CBLen (NullPadded n a) :: Natural

IsCBLen (SizePrefixed pfx a :: Type)

Defined in Binrep.Type.Prefix.Size

Associated Types

type CBLen (SizePrefixed pfx a) :: Natural

IsCBLen (Sized n a :: Type)

Defined in Binrep.Type.Sized

Associated Types

type CBLen (Sized n a) :: Natural

IsCBLen a => IsCBLen (ByteOrdered end a :: Type)

Defined in Binrep.CBLen

Associated Types

type CBLen (ByteOrdered end a) :: Natural

(IsCBLen l, IsCBLen r) => IsCBLen ((l, r) :: Type)

Defined in Binrep.CBLen

Associated Types

type CBLen (l, r) :: Natural

IsCBLen (Refined pr (Refined pl a)) => IsCBLen (Refined (And pl pr) a :: Type)

Defined in Binrep.CBLen

Associated Types

type CBLen (Refined (And pl pr) a) :: Natural

IsCBLen (CountPrefixed pfx f a :: Type)

We can know byte length at compile time _if_ we know it for the prefix and the list-like.

This is extremely unlikely, because then what counting are we even performing for the list-like? But it's a valid instance.

Defined in Binrep.Type.Prefix.Count

Associated Types

type CBLen (CountPrefixed pfx f a) :: Natural

cblen :: forall a. KnownNat (CBLen a) => Int

Reify a type's constant byte length to the term level.

cblen# :: forall a. KnownNat (CBLen a) => Int#

cblenProxy# :: forall a. KnownNat (CBLen a) => Proxy# a -> Int#

data CBLenSym a

Defunctionalization symbol for CBLen.

This is required for parameterized type-level generics e.g. bytezap's GPokeBase.

Instances

type App (CBLenSym :: FunKind k Natural -> Type) (a :: k)

Defined in Binrep.CBLen

type App (CBLenSym :: FunKind k Natural -> Type) (a :: k) = CBLen a

Generically derive CBLen type family instances.

A type having a valid CBLen instance usually indicates one of the following:

• it's a primitive, or extremely simple
• it holds size information in its type
• it's constructed from other constant byte length types

The first two cases must be handled manually. The third case is where Haskell generics excel, and the one this module targets.

You may derive a CBLen type generically for a non-sum type with

instance IsCBLen a where type CBLen a = CBLenGenericNonSum a

You may attempt to derive a CBLen type generically for a sum type with

instance IsCBLen a where type CBLen a = CBLenGenericSum w a

As with other generic sum type handlers, you must provide the type used to store the sum tag for sum types. That sum tag type must have a CBLen, and every constructor must have the same CBLen for a CBLen to be calculated. Not many types will fit those criteria, and the code is not well-tested.

type CBLenGenericSum (w :: Type) a = GCBLen w (Rep a)

Using this necessitates UndecidableInstances.

type CBLenGenericNonSum a = GTFoldMapCAddition CBLenSym (Rep a)

Using this necessitates UndecidableInstances.

type family GCBLen w (gf :: k -> Type) :: Natural where ...

Equations

GCBLen w (D1 _ gf) = GCBLen w gf

GCBLen _ V1 = TypeError ENoEmpty

GCBLen w (l :+: r) = CBLen w + GCBLenCaseMaybe (GCBLenSum (l :+: r))

GCBLen w (C1 _ gf) = GTFoldMapCAddition CBLenSym gf

type family GCBLenSum (gf :: k -> Type) where ...

Equations

GCBLenSum (C1 ('MetaCons name _ _) gf) = JustX (GTFoldMapCAddition CBLenSym gf) name

GCBLenSum (l :+: r) = MaybeEq (GCBLenSum l) (GCBLenSum r)

type family MaybeEq a b where ...

Equations

MaybeEq (JustX n nName) (JustX m _) = If (n == m) (JustX n nName) NothingX

MaybeEq _ _ = NothingX

type family GCBLenCaseMaybe a where ...

I don't know how to pattern match in types without writing type families.

Equations

GCBLenCaseMaybe (JustX n _) = n

GCBLenCaseMaybe NothingX = TypeError ('Text "Two constructors didn't have equal constant size." ':$$: 'Text "Sry dunno how to thread errors thru LOL")

data JustX a b

data NothingX