Copyright | (C) 2012-15 Edward Kmett, Michael Sloan |
---|---|
License | BSD-style (see the file LICENSE) |
Maintainer | Edward Kmett <ekmett@gmail.com> |
Stability | experimental |
Portability | Rank2, MPTCs, fundeps |
Safe Haskell | Trustworthy |
Language | Haskell98 |
The Wrapped
class provides similar functionality as Control.Newtype
,
from the newtype
package, but in a more convenient and efficient form.
There are a few functions from newtype
that are not provided here, because
they can be done with the Iso
directly:
Control.Newtype.overSum
f ≡_Unwrapping
Sum
%~
f Control.Newtype.underSum
f ≡_Wrapping
Sum
%~
f Control.Newtype.overFSum
f ≡mapping
(_Unwrapping
Sum
)%~
f Control.Newtype.underFSum
f ≡mapping
(_Wrapping
Sum
)%~
f
under
can also be used with _Unwrapping
to provide the equivalent of
Control.Newtype.under
. Also, most use cases don't need full polymorphism,
so only the single constructor _Wrapping
functions would be needed.
These equivalences aren't 100% honest, because newtype
's operators
need to rely on two Newtype
constraints. This means that the wrapper used
for the output is not necessarily the same as the input.
- class Wrapped s where
- _Unwrapped' :: Wrapped s => Iso' (Unwrapped s) s
- _Wrapping' :: Wrapped s => (Unwrapped s -> s) -> Iso' s (Unwrapped s)
- _Unwrapping' :: Wrapped s => (Unwrapped s -> s) -> Iso' (Unwrapped s) s
- class Wrapped s => Rewrapped s t
- class (Rewrapped s t, Rewrapped t s) => Rewrapping s t
- _Wrapped :: Rewrapping s t => Iso s t (Unwrapped s) (Unwrapped t)
- _Unwrapped :: Rewrapping s t => Iso (Unwrapped t) (Unwrapped s) t s
- _Wrapping :: Rewrapping s t => (Unwrapped s -> s) -> Iso s t (Unwrapped s) (Unwrapped t)
- _Unwrapping :: Rewrapping s t => (Unwrapped s -> s) -> Iso (Unwrapped t) (Unwrapped s) t s
- op :: Wrapped s => (Unwrapped s -> s) -> s -> Unwrapped s
- ala :: Rewrapping s t => (Unwrapped s -> s) -> ((Unwrapped t -> t) -> e -> s) -> e -> Unwrapped s
- alaf :: (Profunctor p, Rewrapping s t) => (Unwrapped s -> s) -> (p r t -> e -> s) -> p r (Unwrapped t) -> e -> Unwrapped s
Wrapping and Unwrapping monomorphically
Wrapped
provides isomorphisms to wrap and unwrap newtypes or
data types with one constructor.
Nothing
_Unwrapped' :: Wrapped s => Iso' (Unwrapped s) s Source
_Wrapping' :: Wrapped s => (Unwrapped s -> s) -> Iso' s (Unwrapped s) Source
This is a convenient version of _Wrapped
with an argument that's ignored.
The user supplied function is ignored, merely its type is used.
_Unwrapping' :: Wrapped s => (Unwrapped s -> s) -> Iso' (Unwrapped s) s Source
This is a convenient version of _Wrapped
with an argument that's ignored.
The user supplied function is ignored, merely its type is used.
Wrapping and unwrapping polymorphically
class Wrapped s => Rewrapped s t Source
(~) * t PatternMatchFail => Rewrapped PatternMatchFail t Source | |
(~) * t RecSelError => Rewrapped RecSelError t Source | |
(~) * t RecConError => Rewrapped RecConError t Source | |
(~) * t RecUpdError => Rewrapped RecUpdError t Source | |
(~) * t NoMethodError => Rewrapped NoMethodError t Source | |
(~) * t AssertionFailed => Rewrapped AssertionFailed t Source | |
(~) * t ErrorCall => Rewrapped ErrorCall t Source | |
(~) * t All => Rewrapped All t Source | |
(~) * t Any => Rewrapped Any t Source | |
(~) * t IntSet => Rewrapped IntSet t Source | Use |
(~) * t (Identity b) => Rewrapped (Identity a) t Source | |
(~) * t (ZipList b) => Rewrapped (ZipList a) t Source | |
(~) * t (Dual b) => Rewrapped (Dual a) t Source | |
(~) * t (Endo b) => Rewrapped (Endo b) t Source | |
(~) * t (Sum b) => Rewrapped (Sum a) t Source | |
(~) * t (Product b) => Rewrapped (Product a) t Source | |
(~) * t (First b) => Rewrapped (First a) t Source | |
(~) * t (Last b) => Rewrapped (Last a) t Source | |
(~) * t (IntMap a') => Rewrapped (IntMap a) t Source | Use |
((~) * t (Set a'), Ord a) => Rewrapped (Set a) t Source | Use |
(~) * t (Seq a') => Rewrapped (Seq a) t Source | |
(~) * t (Predicate b) => Rewrapped (Predicate a) t Source | |
(~) * t (Comparison b) => Rewrapped (Comparison a) t Source | |
(~) * t (Equivalence b) => Rewrapped (Equivalence a) t Source | |
(~) * t (Min b) => Rewrapped (Min a) t Source | |
(~) * t (Max b) => Rewrapped (Max a) t Source | |
(~) * t (First b) => Rewrapped (First a) t Source | |
(~) * t (Last b) => Rewrapped (Last a) t Source | |
(~) * t (WrappedMonoid b) => Rewrapped (WrappedMonoid a) t Source | |
(~) * t (Option b) => Rewrapped (Option a) t Source | |
(~) * t (NonEmpty b) => Rewrapped (NonEmpty a) t Source | |
((~) * t (HashSet a'), Hashable a, Eq a) => Rewrapped (HashSet a) t Source | Use |
(~) * t (Vector a') => Rewrapped (Vector a) t Source | |
(Unbox a, (~) * t (Vector a')) => Rewrapped (Vector a) t Source | |
(Storable a, (~) * t (Vector a')) => Rewrapped (Vector a) t Source | |
(Prim a, (~) * t (Vector a')) => Rewrapped (Vector a) t Source | |
(~) * t (Op a' b') => Rewrapped (Op a b) t Source | |
(~) * t (Const a' x') => Rewrapped (Const a x) t Source | |
(~) * t (WrappedMonad m' a') => Rewrapped (WrappedMonad m a) t Source | |
((~) * t (ArrowMonad m' a'), ArrowApply m) => Rewrapped (ArrowMonad m a) t Source | |
(~) * t (IdentityT n b) => Rewrapped (IdentityT m a) t Source | |
((~) * t (Map k' a'), Ord k) => Rewrapped (Map k a) t Source | Use |
(~) * t (ListT n b) => Rewrapped (ListT m a) t Source | |
(~) * t (Reverse g b) => Rewrapped (Reverse f a) t Source | |
(~) * t (Backwards g b) => Rewrapped (Backwards f a) t Source | |
(~) * t (MaybeT n b) => Rewrapped (MaybeT m a) t Source | |
(~) * t (Constant a' b') => Rewrapped (Constant a b) t Source | |
((~) * t (HashMap k' a'), Hashable k, Eq k) => Rewrapped (HashMap k a) t Source | Use |
(~) * t (WrappedArrow a' b' c') => Rewrapped (WrappedArrow a b c) t Source | |
(~) * t (Kleisli m' a' b') => Rewrapped (Kleisli m a b) t Source | |
(~) * t (Alt k g b) => Rewrapped (Alt k f a) t Source | |
(~) * t (Coproduct f' g' a') => Rewrapped (Coproduct f g a) t Source | |
(~) * t (TracedT m' w' a') => Rewrapped (TracedT m w a) t Source | |
(~) * t (Compose f' g' a') => Rewrapped (Compose f g a) t Source | |
(~) * t (ComposeFC f' g' a') => Rewrapped (ComposeFC f g a) t Source | |
(~) * t (ComposeCF f' g' a') => Rewrapped (ComposeCF f g a) t Source | |
(~) * t (ContT r' m' a') => Rewrapped (ContT r m a) t Source | |
(~) * t (ReaderT r n b) => Rewrapped (ReaderT r m a) t Source | |
(~) * t (StateT s' m' a') => Rewrapped (StateT s m a) t Source | |
(~) * t (StateT s' m' a') => Rewrapped (StateT s m a) t Source | |
(~) * t (ErrorT e' m' a') => Rewrapped (ErrorT e m a) t Source | |
(~) * t (WriterT w' m' a') => Rewrapped (WriterT w m a) t Source | |
(~) * t (WriterT w' m' a') => Rewrapped (WriterT w m a) t Source | |
(~) * t (Compose f' g' a') => Rewrapped (Compose f g a) t Source | |
(~) * t (Tagged k s' a') => Rewrapped (Tagged k s a) t Source | |
(~) * t (RWST r' w' s' m' a') => Rewrapped (RWST r w s m a) t Source | |
(~) * t (RWST r' w' s' m' a') => Rewrapped (RWST r w s m a) t Source | |
class (Rewrapped s t, Rewrapped t s) => Rewrapping s t Source
(Rewrapped s t, Rewrapped t s) => Rewrapping s t Source | |
_Wrapped :: Rewrapping s t => Iso s t (Unwrapped s) (Unwrapped t) Source
Work under a newtype wrapper.
>>>
Const "hello" & _Wrapped %~ Prelude.length & getConst
5
_Wrapped
≡from
_Unwrapped
_Unwrapped
≡from
_Wrapped
_Unwrapped :: Rewrapping s t => Iso (Unwrapped t) (Unwrapped s) t s Source
_Wrapping :: Rewrapping s t => (Unwrapped s -> s) -> Iso s t (Unwrapped s) (Unwrapped t) Source
This is a convenient version of _Wrapped
with an argument that's ignored.
The user supplied function is ignored, merely its types are used.
_Unwrapping :: Rewrapping s t => (Unwrapped s -> s) -> Iso (Unwrapped t) (Unwrapped s) t s Source
This is a convenient version of _Unwrapped
with an argument that's ignored.
The user supplied function is ignored, merely its types are used.
Operations
ala :: Rewrapping s t => (Unwrapped s -> s) -> ((Unwrapped t -> t) -> e -> s) -> e -> Unwrapped s Source
This combinator is based on ala
from Conor McBride's work on Epigram.
As with _Wrapping
, the user supplied function for the newtype is ignored.
>>>
ala Sum foldMap [1,2,3,4]
10
>>>
ala All foldMap [True,True]
True
>>>
ala All foldMap [True,False]
False
>>>
ala Any foldMap [False,False]
False
>>>
ala Any foldMap [True,False]
True
>>>
ala Sum foldMap [1,2,3,4]
10
>>>
ala Product foldMap [1,2,3,4]
24
alaf :: (Profunctor p, Rewrapping s t) => (Unwrapped s -> s) -> (p r t -> e -> s) -> p r (Unwrapped t) -> e -> Unwrapped s Source
This combinator is based on ala'
from Conor McBride's work on Epigram.
As with _Wrapping
, the user supplied function for the newtype is ignored.
>>>
alaf Sum foldMap Prelude.length ["hello","world"]
10