Generic.Data.Internal.Microsurgery

Surgeries that are just coerce.

Warning

This is an internal module: it is not subject to any versioning policy, breaking changes can happen at any time.

If something here seems useful, please report it or create a pull request to export it from an external module.

Surgery

type Surgery (s :: *) (a :: *) = Generically (Surgery' s a)

Apply a microsurgery s to a type a for DerivingVia.

For the Monoid class, see ProductSurgery.

Example

{-# LANGUAGE DerivingVia #-}

-- The constructors must be visible.
import Generic.Data.Microsurgery
  (Surgery, Surgery'(..), Generically(..), Derecordify)

data T = T { unT :: Int }
  deriving Show via (Surgery Derecordify T)

-- T won't be shown as a record:
--   show (T {unT = 3}) == "T 3"

type ProductSurgery (s :: *) (a :: *) = GenericProduct (Surgery' s a)

Apply a microsurgery s to a type a for DerivingVia for the Monoid class.

type Surgeries (s :: [*]) (a :: *) = Surgery (Cat s) a

Plural of Surgery. Apply a list of microsurgeries.

type ProductSurgeries (s :: [*]) (a :: *) = ProductSurgery (Cat s) a

Plural of ProductSurgery. Apply a list of microsurgeries.

newtype Surgery' (s :: *) (a :: *)

See Surgery.

Constructors

Surgery'

Fields

• unSurgery' :: a

Instances

(Generic a, Coercible (GSurgery s (Rep a)) (Rep a)) => Generic (Surgery' s a)

Defined in Generic.Data.Internal.Microsurgery

Associated Types

type Rep (Surgery' s a) :: Type -> Type

Methods

from :: Surgery' s a -> Rep (Surgery' s a) x

to :: Rep (Surgery' s a) x -> Surgery' s a

type Rep (Surgery' s a)

Defined in Generic.Data.Internal.Microsurgery

type Rep (Surgery' s a) = GSurgery s (Rep a)

type family GSurgery (s :: *) (f :: k -> *) :: k -> *

Apply a microsurgery represented by a symbol s (declared as a dummy data type) to a generic representation f.

Instances

type GSurgery Derecordify (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery Derecordify (f :: k -> Type) = GDerecordify f

type GSurgery Typeage (M1 D ('MetaData nm md pk _nt) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery Typeage (M1 D ('MetaData nm md pk _nt) f :: k -> Type) = M1 D ('MetaData nm md pk 'False) f

type GSurgery (CopyRep a) (_1 :: Type -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (CopyRep a) (_1 :: Type -> Type) = Rep a

type GSurgery (RenameFields rnm) (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (RenameFields rnm) (f :: k -> Type) = GRenameFields rnm f

type GSurgery (RenameConstrs rnm) (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (RenameConstrs rnm) (f :: k -> Type) = GRenameConstrs rnm f

type GSurgery (OnFields f) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (OnFields f) (g :: k -> Type) = GOnFields f g

type GSurgery (Cat (s ': ss)) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (Cat (s ': ss)) (g :: k -> Type) = GSurgery s (GSurgery (Cat ss) g)

type GSurgery (Cat ('[] :: [Type])) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (Cat ('[] :: [Type])) (g :: k -> Type) = g

type GSurgery (OnField s f) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (OnField s f) (g :: k -> Type) = GOnField s f g

Derecordify

derecordify :: Coercible (GSurgery Derecordify f) f => Data f p -> Data (GSurgery Derecordify f) p

underecordify :: Coercible f (GSurgery Derecordify f) => Data (GSurgery Derecordify f) p -> Data f p

data Derecordify :: *

Forget that a type was declared using record syntax.

data Foo = Bar { baz :: Zap }

-- becomes --

data Foo = Bar Zap

Concretely, set the last field of MetaCons to False and forget field names.

This is a defunctionalized symbol, applied using GSurgery or Surgery.

Instances

type GSurgery Derecordify (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery Derecordify (f :: k -> Type) = GDerecordify f

type family GDerecordify (f :: k -> *) :: k -> *

Instances

type GDerecordify (U1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (U1 :: k -> Type) = U1 :: k -> Type

type GDerecordify (V1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (V1 :: k -> Type) = V1 :: k -> Type

type GDerecordify (f :*: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (f :*: g :: k -> Type) = GDerecordify f :*: GDerecordify g

type GDerecordify (f :+: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (f :+: g :: k -> Type) = GDerecordify f :+: GDerecordify g

type GDerecordify (M1 S ('MetaSel _nm su ss ds) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (M1 S ('MetaSel _nm su ss ds) f :: k -> Type) = M1 S ('MetaSel ('Nothing :: Maybe Symbol) su ss ds) f

type GDerecordify (M1 C ('MetaCons nm fx _isRecord) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (M1 C ('MetaCons nm fx _isRecord) f :: k -> Type) = M1 C ('MetaCons nm fx 'False) (GDerecordify f)

type GDerecordify (M1 D m f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GDerecordify (M1 D m f :: k -> Type) = M1 D m (GDerecordify f)

Type aging ("denewtypify")

typeage :: Coercible (GSurgery Typeage f) f => Data f p -> Data (GSurgery Typeage f) p

untypeage :: Coercible f (GSurgery Typeage f) => Data (GSurgery Typeage f) p -> Data f p

data Typeage :: *

Forget that a type is a newtype. (The pun is that "aging" a type makes it no longer "new".)

newtype Foo = Bar Baz

-- becomes --

data Foo = Bar Baz

This is a defunctionalized symbol, applied using GSurgery or Surgery.

Instances

type GSurgery Typeage (M1 D ('MetaData nm md pk _nt) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery Typeage (M1 D ('MetaData nm md pk _nt) f :: k -> Type) = M1 D ('MetaData nm md pk 'False) f

Renaming

renameFields :: forall rnm f p. Coercible (GSurgery (RenameFields rnm) f) f => Data f p -> Data (GSurgery (RenameFields rnm) f) p

unrenameFields :: forall rnm f p. Coercible (GSurgery (RenameFields rnm) f) f => Data f p -> Data (GSurgery (RenameFields rnm) f) p

renameConstrs :: forall rnm f p. Coercible (GSurgery (RenameConstrs rnm) f) f => Data f p -> Data (GSurgery (RenameConstrs rnm) f) p

unrenameConstrs :: forall rnm f p. Coercible (GSurgery (RenameConstrs rnm) f) f => Data f p -> Data (GSurgery (RenameConstrs rnm) f) p

data RenameFields (rnm :: *) :: *

Rename fields using the function rnm given as a parameter.

data Foo = Bar { baz :: Zap }

-- becomes, renaming "baz" to "bag" --

data Foo = Bar { bag :: Zap }

This is a defunctionalized symbol, applied using GSurgery or Surgery.

Instances

type GSurgery (RenameFields rnm) (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (RenameFields rnm) (f :: k -> Type) = GRenameFields rnm f

type family GRenameFields (rnm :: *) (f :: k -> *) :: k -> *

Instances

type GRenameFields rnm (U1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (U1 :: k -> Type) = U1 :: k -> Type

type GRenameFields rnm (V1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (V1 :: k -> Type) = V1 :: k -> Type

type GRenameFields rnm (f :*: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (f :*: g :: k -> Type) = GRenameFields rnm f :*: GRenameFields rnm g

type GRenameFields rnm (f :+: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (f :+: g :: k -> Type) = GRenameFields rnm f :+: GRenameFields rnm g

type GRenameFields rnm (M1 C m f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (M1 C m f :: k -> Type) = M1 C m (GRenameFields rnm f)

type GRenameFields rnm (M1 D m f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (M1 D m f :: k -> Type) = M1 D m (GRenameFields rnm f)

type GRenameFields rnm (M1 S ('MetaSel ('Just nm) su ss ds) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameFields rnm (M1 S ('MetaSel ('Just nm) su ss ds) f :: k -> Type) = M1 S ('MetaSel ('Just (rnm @@ nm)) su ss ds) f

data RenameConstrs (rnm :: *) :: *

Rename constructors using the function rnm given as a parameter.

data Foo = Bar { baz :: Zap }

-- becomes, renaming "Bar" to "Car" --

data Foo = Car { baz :: Zap }

This is a defunctionalized symbol, applied using GSurgery or Surgery.

Instances

type GSurgery (RenameConstrs rnm) (f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (RenameConstrs rnm) (f :: k -> Type) = GRenameConstrs rnm f

type family GRenameConstrs (rnm :: *) (f :: k -> *) :: k -> *

Instances

type GRenameConstrs rnm (V1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameConstrs rnm (V1 :: k -> Type) = V1 :: k -> Type

type GRenameConstrs rnm (f :*: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameConstrs rnm (f :*: g :: k -> Type) = GRenameConstrs rnm f :*: GRenameConstrs rnm g

type GRenameConstrs rnm (f :+: g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameConstrs rnm (f :+: g :: k -> Type) = GRenameConstrs rnm f :+: GRenameConstrs rnm g

type GRenameConstrs rnm (M1 D m f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameConstrs rnm (M1 D m f :: k -> Type) = M1 D m (GRenameConstrs rnm f)

type GRenameConstrs rnm (M1 C ('MetaCons nm fi ir) f :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GRenameConstrs rnm (M1 C ('MetaCons nm fi ir) f :: k -> Type) = M1 C ('MetaCons (rnm @@ nm) fi ir) f

Defining symbol functions

type family (f :: *) @@ (s :: Symbol) :: Symbol

f @@ s is the application of a type-level function symbolized by f to a s :: Symbol.

A function FooToBar can be defined as follows:

data FooToBar
type instance FooToBar @@ "foo" = "bar"

Instances

type SError @@ s

Defined in Generic.Data.Internal.Microsurgery

type SError @@ s = TypeError ('Text "Invalid name: " :<>: 'ShowType s) :: Symbol

type SId @@ s

Defined in Generic.Data.Internal.Microsurgery

type SId @@ s = s

type (SConst z) @@ _s

Defined in Generic.Data.Internal.Microsurgery

type (SConst z) @@ _s = z

type (SRename xs f) @@ s

Defined in Generic.Data.Internal.Microsurgery

type (SRename xs f) @@ s = SRename' xs f s

data SId

Identity function Symbol -> Symbol.

Instances

type SId @@ s

Defined in Generic.Data.Internal.Microsurgery

type SId @@ s = s

data SError

Empty function (compile-time error when applied).

Instances

type SError @@ s

Defined in Generic.Data.Internal.Microsurgery

type SError @@ s = TypeError ('Text "Invalid name: " :<>: 'ShowType s) :: Symbol

data SConst (s :: Symbol)

Constant function.

Instances

type (SConst z) @@ _s

Defined in Generic.Data.Internal.Microsurgery

type (SConst z) @@ _s = z

data SRename (xs :: [(Symbol, Symbol)]) (f :: *)

Define a function for a fixed set of strings, and fall back to f for the others.

Instances

type (SRename xs f) @@ s

Defined in Generic.Data.Internal.Microsurgery

type (SRename xs f) @@ s = SRename' xs f s

type family SRename' (xs :: [(Symbol, Symbol)]) (f :: *) (s :: Symbol) where ...

Closed type family for SRename.

Equations

SRename' '[] f s = f @@ s

SRename' ('(s, t) ': _xs) _f s = t

SRename' ('(_r, _t) ': xs) f s = SRename' xs f s

Other

class UnifyRep (f :: k -> *) (g :: k -> *)

Unify the "spines" of two generic representations (the "spine" is everything except the field types).

Instances

g' ~ (V1 :: k -> Type) => UnifyRep (V1 :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

g' ~ (U1 :: k -> Type) => UnifyRep (U1 :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

g' ~ (K1 i b :: k -> Type) => UnifyRep (K1 i a :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

(g' ~ (g1 :*: g2), UnifyRep f1 g1, UnifyRep f2 g2) => UnifyRep (f1 :*: f2 :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

(g' ~ (g1 :+: g2), UnifyRep f1 g1, UnifyRep f2 g2) => UnifyRep (f1 :+: f2 :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

(g' ~ M1 s c g, UnifyRep f g) => UnifyRep (M1 s c f :: k -> Type) (g' :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

onData :: (UnifyRep r s, UnifyRep s r) => p (Data r x) (Data s y) -> p (Data r x) (Data s y)

onData :: _ => (Data r x -> Data s y) -> (Data r x -> Data s y)  -- possible specialization

Can be used with generic-lens for type-changing field updates with field_ (and possibly other generic optics).

A specialization of the identity function to be used to fix types of functions on Data, unifying the "spines" of input and output generic representations (the "spine" is everything except field types, which may thus change).

data OnFields (f :: * -> *) :: *

Apply a type constructor f to every field type of a generic representation r.

data Color = RGB
  { r :: Int
  , g :: Int
  , b :: Int }

-- becomes --

data Color f = RGB
  { r :: f Int
  , g :: f Int
  , b :: f Int }

This is a defunctionalized symbol, applied using GSurgery or Surgery.

Instances

type GSurgery (OnFields f) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (OnFields f) (g :: k -> Type) = GOnFields f g

type family GOnFields (f :: * -> *) (g :: k -> *) :: k -> *

Instances

type GOnFields f (V1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (V1 :: k -> Type) = V1 :: k -> Type

type GOnFields f (U1 :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (U1 :: k -> Type) = U1 :: k -> Type

type GOnFields f (K1 i a :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (K1 i a :: k -> Type) = K1 i (f a) :: k -> Type

type GOnFields f (r :*: s :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (r :*: s :: k -> Type) = GOnFields f r :*: GOnFields f s

type GOnFields f (r :+: s :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (r :+: s :: k -> Type) = GOnFields f r :+: GOnFields f s

type GOnFields f (M1 s m r :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GOnFields f (M1 s m r :: k -> Type) = M1 s m (GOnFields f r)

type DOnFields (f :: * -> *) (a :: *) = Data (GSurgery (OnFields f) (Rep a)) ()

Apply a type constructor f to every field type of a type a to make a synthetic type.

data OnField (s :: Symbol) (f :: * -> *) :: *

Apply a type constructor f to the field named s in a generic record r.

data Vec a = Vec
  { len :: Int
  , contents :: [a] }

-- with (OnField "len" Sum) becomes --

data Vec a = Vec
  { len :: Sum Int
  , contents :: [a] }

This is a defunctionalized symbol, applied using GSurgery or Surgery. See also the synonym (%~).

Instances

type GSurgery (OnField s f) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (OnField s f) (g :: k -> Type) = GOnField s f g

type family GOnField (x :: Symbol) (f :: * -> *) (g :: k -> *) :: k -> * where ...

Equations

GOnField x f (M1 S ('MetaSel ('Just x) a b c) (K1 i t)) = M1 S ('MetaSel ('Just x) a b c) (K1 i (f t))

GOnField x f (M1 S m r) = M1 S m r

GOnField x f (M1 C m r) = M1 C m (GOnField x f r)

GOnField x f (M1 D m r) = M1 D m (GOnField x f r)

GOnField x f (r :+: s) = GOnField x f r :+: GOnField x f s

GOnField x f (r :*: s) = GOnField x f r :*: GOnField x f s

GOnField x f (K1 i a) = K1 i (f a)

GOnField x f U1 = U1

GOnField x f V1 = V1

type (%~) = OnField infixr 4

Infix name for OnField. To be used with Surgeries or Cat.

Examples

Transform one Int field into Sum Int for deriving Monoid:

data Vec a = Vec
  { len :: Int
  , contents :: [a] }
  deriving Generic
  deriving (Eq, Show) via Generically (Vec a)
  deriving (Semigroup, Monoid) via ProductSurgeries '["len" %~ Sum] (Vec a)

Wrap unshowable fields in Opaque for deriving Show:

data Unshowable = Unshowable
  { fun :: Int -> Int
  , io :: IO Bool
  , int :: Int }
  deriving Generic
  deriving Show via Surgeries '["fun" %~ Opaque, "io" %~ Opaque] Unshowable

-- show (Unshowable id (pure True) 42) = "Unshowable _ _ 42"

data Cat (ss :: [*]) :: *

Compose surgeries together.

Instances

type GSurgery (Cat (s ': ss)) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (Cat (s ': ss)) (g :: k -> Type) = GSurgery s (GSurgery (Cat ss) g)

type GSurgery (Cat ('[] :: [Type])) (g :: k -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (Cat ('[] :: [Type])) (g :: k -> Type) = g

type DCat (ss :: [*]) (a :: *) = Data (GSurgery (Cat ss) (Rep a)) ()

Make a synthetic type (Data) by chaining multiple surgeries.

data CopyRep (a :: *) :: *

Change the generic representation to that of another type a.

Instances

type GSurgery (CopyRep a) (_1 :: Type -> Type)

Defined in Generic.Data.Internal.Microsurgery

type GSurgery (CopyRep a) (_1 :: Type -> Type) = Rep a

copyRep :: forall a f p. Coercible (GSurgery (CopyRep a) f) f => Data f p -> Data (GSurgery (CopyRep a) f) p

uncopyRep :: forall a f p. Coercible f (GSurgery (CopyRep a) f) => Data (GSurgery (CopyRep a) f) p -> Data f p