Portability | Rank2Types |
---|---|
Stability | provisional |
Maintainer | Edward Kmett <ekmett@gmail.com> |
Safe Haskell | Trustworthy |
- class Field1 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _1 :: IndexedLens Int s t a b
- class Field2 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _2 :: IndexedLens Int s t a b
- class Field3 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _3 :: IndexedLens Int s t a b
- class Field4 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _4 :: IndexedLens Int s t a b
- class Field5 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _5 :: IndexedLens Int s t a b
- class Field6 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _6 :: IndexedLens Int s t a b
- class Field7 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _7 :: IndexedLens Int s t a b
- class Field8 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _8 :: IndexedLens Int s t a b
- class Field9 s t a b | s -> a, t -> b, s b -> t, t a -> s where
- _9 :: IndexedLens Int s t a b
Tuples
class Field1 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provides access to 1st field of a tuple.
_1 :: IndexedLens Int s t a bSource
Access the 1st field of a tuple (and possibly change its type).
>>>
(1,2)^._1
1
>>>
_1 .~ "hello" $ (1,2)
("hello",2)
>>>
(1,2) & _1 .~ "hello"
("hello",2)
>>>
_1 putStrLn ("hello","world")
hello ((),"world")
This can also be used on larger tuples as well:
>>>
(1,2,3,4,5) & _1 +~ 41
(42,2,3,4,5)
_1
::Lens
(a,b) (a',b) a a'_1
::Lens
(a,b,c) (a',b,c) a a'_1
::Lens
(a,b,c,d) (a',b,c,d) a a' ..._1
::Lens
(a,b,c,d,e,f,g,h,i) (a',b,c,d,e,f,g,h,i) a a'
Field1 (Identity a) (Identity b) a b | |
Field1 (a, b) (a', b) a a' |
|
Field1 (a, b, c) (a', b, c) a a' | |
Field1 (a, b, c, d) (a', b, c, d) a a' | |
Field1 (a, b, c, d, e) (a', b, c, d, e) a a' | |
Field1 (a, b, c, d, e, f) (a', b, c, d, e, f) a a' | |
Field1 (a, b, c, d, e, f, g) (a', b, c, d, e, f, g) a a' | |
Field1 (a, b, c, d, e, f, g, h) (a', b, c, d, e, f, g, h) a a' | |
Field1 (a, b, c, d, e, f, g, h, i) (a', b, c, d, e, f, g, h, i) a a' |
class Field2 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provides access to the 2nd field of a tuple.
_2 :: IndexedLens Int s t a bSource
Access the 2nd field of a tuple.
>>>
_2 .~ "hello" $ (1,(),3,4)
(1,"hello",3,4)
>>>
(1,2,3,4) & _2 *~ 3
(1,6,3,4)
>>>
_2 print (1,2)
2 (1,())
anyOf
_2
:: (s ->Bool
) -> (a, s) ->Bool
traverse
.
_2
:: (Applicative
f,Traversable
t) => (a -> f b) -> t (s, a) -> f (t (s, b))foldMapOf
(traverse
.
_2
) :: (Traversable
t,Monoid
m) => (s -> m) -> t (b, s) -> m
Field2 (a, b) (a, b') b b' |
|
Field2 (a, b, c) (a, b', c) b b' | |
Field2 (a, b, c, d) (a, b', c, d) b b' | |
Field2 (a, b, c, d, e) (a, b', c, d, e) b b' | |
Field2 (a, b, c, d, e, f) (a, b', c, d, e, f) b b' | |
Field2 (a, b, c, d, e, f, g) (a, b', c, d, e, f, g) b b' | |
Field2 (a, b, c, d, e, f, g, h) (a, b', c, d, e, f, g, h) b b' | |
Field2 (a, b, c, d, e, f, g, h, i) (a, b', c, d, e, f, g, h, i) b b' |
class Field3 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provides access to the 3rd field of a tuple.
_3 :: IndexedLens Int s t a bSource
Access the 3rd field of a tuple.
Field3 (a, b, c) (a, b, c') c c' | |
Field3 (a, b, c, d) (a, b, c', d) c c' | |
Field3 (a, b, c, d, e) (a, b, c', d, e) c c' | |
Field3 (a, b, c, d, e, f) (a, b, c', d, e, f) c c' | |
Field3 (a, b, c, d, e, f, g) (a, b, c', d, e, f, g) c c' | |
Field3 (a, b, c, d, e, f, g, h) (a, b, c', d, e, f, g, h) c c' | |
Field3 (a, b, c, d, e, f, g, h, i) (a, b, c', d, e, f, g, h, i) c c' |
class Field4 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provide access to the 4th field of a tuple.
_4 :: IndexedLens Int s t a bSource
Access the 4th field of a tuple.
Field4 (a, b, c, d) (a, b, c, d') d d' | |
Field4 (a, b, c, d, e) (a, b, c, d', e) d d' | |
Field4 (a, b, c, d, e, f) (a, b, c, d', e, f) d d' | |
Field4 (a, b, c, d, e, f, g) (a, b, c, d', e, f, g) d d' | |
Field4 (a, b, c, d, e, f, g, h) (a, b, c, d', e, f, g, h) d d' | |
Field4 (a, b, c, d, e, f, g, h, i) (a, b, c, d', e, f, g, h, i) d d' |
class Field5 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provides access to the 5th field of a tuple.
_5 :: IndexedLens Int s t a bSource
Access the 5th field of a tuple.
class Field6 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provides access to the 6th element of a tuple.
_6 :: IndexedLens Int s t a bSource
Access the 6th field of a tuple.
class Field7 s t a b | s -> a, t -> b, s b -> t, t a -> s whereSource
Provide access to the 7th field of a tuple.
_7 :: IndexedLens Int s t a bSource
Access the 7th field of a tuple.