Portability | non-portable |
---|---|
Stability | provisional |
Maintainer | Edward Kmett <ekmett@gmail.com> |
Safe Haskell | Trustworthy |
- type Review s t a b = forall p f. (Reviewable p, Settable f) => Overloaded p f s t a b
- type Review' t b = Review t t b b
- type AReview s t a b = Overloaded Reviewed Identity s t a b
- type AReview' t b = AReview t t b b
- unto :: (Reviewable p, Functor f) => (b -> t) -> Overloaded p f s t a b
- re :: AReview s t a b -> Getter b t
- review :: MonadReader b m => AReview s t a b -> m t
- reviews :: MonadReader b m => AReview s t a b -> (t -> r) -> m r
- reuse :: MonadState b m => AReview s t a b -> m t
- reuses :: MonadState b m => AReview s t a b -> (t -> r) -> m r
- (#) :: AReview s t a b -> b -> t
- class Profunctor p => Reviewable p where
- retagged :: p a b -> p s b
Reviewing
type Review s t a b = forall p f. (Reviewable p, Settable f) => Overloaded p f s t a bSource
type AReview s t a b = Overloaded Reviewed Identity s t a bSource
unto :: (Reviewable p, Functor f) => (b -> t) -> Overloaded p f s t a bSource
re :: AReview s t a b -> Getter b tSource
Turn a Prism
or Iso
around to build a Getter
.
If you have an Iso
, from
is a more powerful version of this function
that will return an Iso
instead of a mere Getter
.
>>>
5 ^.re _Left
Left 5
>>>
6 ^.re (_Left.unto succ)
Left 7
review
≡view
.
re
reviews
≡views
.
re
reuse
≡use
.
re
reuses
≡uses
.
re
re
::Prism
s t a b ->Getter
b tre
::Iso
s t a b ->Getter
b t
review :: MonadReader b m => AReview s t a b -> m tSource
This can be used to turn an Iso
or Prism
around and view
a value (or the current environment) through it the other way.
review
≡view
.
re
review
.unto
≡id
>>>
review _Left "mustard"
Left "mustard"
>>>
review (unto succ) 5
6
Usually review
is used in the (->)
Monad
with a Prism
or Iso
, in which case it may be useful to think of
it as having one of these more restricted type signatures:
review
::Iso'
s a -> a -> sreview
::Prism'
s a -> a -> s
However, when working with a Monad
transformer stack, it is sometimes useful to be able to review
the current environment, in which case one of
these more slightly more liberal type signatures may be beneficial to think of it as having:
review
::MonadReader
a m =>Iso'
s a -> m sreview
::MonadReader
a m =>Prism'
s a -> m s
reviews :: MonadReader b m => AReview s t a b -> (t -> r) -> m rSource
This can be used to turn an Iso
or Prism
around and view
a value (or the current environment) through it the other way,
applying a function.
reviews
≡views
.
re
reviews
(unto
f) g ≡ g.
f
>>>
reviews _Left isRight "mustard"
False
>>>
reviews (unto succ) (*2) 3
8
Usually this function is used in the (->)
Monad
with a Prism
or Iso
, in which case it may be useful to think of
it as having one of these more restricted type signatures:
reviews
::Iso'
s a -> (s -> r) -> a -> rreviews
::Prism'
s a -> (s -> r) -> a -> r
However, when working with a Monad
transformer stack, it is sometimes useful to be able to review
the current environment, in which case one of
these more slightly more liberal type signatures may be beneficial to think of it as having:
reviews
::MonadReader
a m =>Iso'
s a -> (s -> r) -> m rreviews
::MonadReader
a m =>Prism'
s a -> (s -> r) -> m r
reuse :: MonadState b m => AReview s t a b -> m tSource
This can be used to turn an Iso
or Prism
around and use
a value (or the current environment) through it the other way.
reuse
≡use
.
re
reuse
.
unto
≡gets
>>>
evalState (reuse _Left) 5
Left 5
>>>
evalState (reuse (unto succ)) 5
6
reuse
::MonadState
a m =>Prism'
s a -> m sreuse
::MonadState
a m =>Iso'
s a -> m s
reuses :: MonadState b m => AReview s t a b -> (t -> r) -> m rSource
This can be used to turn an Iso
or Prism
around and use
the current state through it the other way,
applying a function.
reuses
≡uses
.
re
reuses
(unto
f) g ≡gets
(g.
f)
>>>
evalState (reuses _Left isLeft) (5 :: Int)
True
reuses
::MonadState
a m =>Prism'
s a -> (s -> r) -> m rreuses
::MonadState
a m =>Iso'
s a -> (s -> r) -> m r
(#) :: AReview s t a b -> b -> tSource
An infix alias for review
.
unto
f # x ≡ f x l # x ≡ x^.
re
l
This is commonly used when using a Prism
as a smart constructor.
>>>
_Left # 4
Left 4
But it can be used for any Prism
>>>
base 16 # 123
"7b"
(#) ::Iso'
s a -> a -> s (#) ::Prism'
s a -> a -> s (#) ::Review'
s a -> a -> s (#) ::Equality'
s a -> a -> s
Reviewable Profunctors
class Profunctor p => Reviewable p whereSource
This provides a dual notion to that of Gettable
.