Network.GRPC.Common.Protobuf

& is a reverse application operator. This provides notational convenience. Its precedence is one higher than that of the forward application operator $, which allows & to be nested in $.

This is a version of flip id, where id is specialized from a -> a to (a -> b) -> (a -> b) which by the associativity of (->) is (a -> b) -> a -> b. flipping this yields a -> (a -> b) -> b which is the type signature of &

Examples

>>> 5 & (+1) & show"6"

>>> sqrt $ [1 / n^2 | n <- [1..1000]] & sum & (*6)3.1406380562059946

Replace the target of a Lens or all of the targets of a Setter or Traversal with a constant value.

This is an infix version of set, provided for consistency with (.=).

f <$ a ≡ mapped .~ f $ a

>>> (a,b,c,d) & _4 .~ e(a,b,c,e)

>>> (42,"world") & _1 .~ "hello"("hello","world")

>>> (a,b) & both .~ c(c,c)

(.~) :: Setter s t a b    -> b -> s -> t
(.~) :: Iso s t a b       -> b -> s -> t
(.~) :: Lens s t a b      -> b -> s -> t
(.~) :: Traversal s t a b -> b -> s -> t

View the value pointed to by a Getter or Lens or the result of folding over all the results of a Control.Lens.Fold.Fold or Control.Lens.Traversal.Traversal that points at a monoidal values.

This is the same operation as view with the arguments flipped.

The fixity and semantics are such that subsequent field accesses can be performed with (Prelude..).

>>> (a,b)^._2b

>>> ("hello","world")^._2"world"

>>> import Data.Complex>>> ((0, 1 :+ 2), 3)^._1._2.to magnitude2.23606797749979

(^.) ::             s -> Getter s a     -> a
(^.) :: Monoid m => s -> Control.Lens.Fold.Fold s m       -> m
(^.) ::             s -> Control.Lens.Iso.Iso' s a       -> a
(^.) ::             s -> Lens' s a      -> a
(^.) :: Monoid m => s -> Control.Lens.Traversal.Traversal' s m -> m

Modifies the target of a Lens or all of the targets of a Setter or Traversal with a user supplied function.

This is an infix version of over.

fmap f ≡ mapped %~ f
fmapDefault f ≡ traverse %~ f

>>> (a,b,c) & _3 %~ f(a,b,f c)

>>> (a,b) & both %~ f(f a,f b)

>>> _2 %~ length $ (1,"hello")(1,5)

>>> traverse %~ f $ [a,b,c][f a,f b,f c]

>>> traverse %~ even $ [1,2,3][False,True,False]

>>> traverse.traverse %~ length $ [["hello","world"],["!!!"]][[5,5],[3]]

(%~) :: Setter s t a b    -> (a -> b) -> s -> t
(%~) :: Iso s t a b       -> (a -> b) -> s -> t
(%~) :: Lens s t a b      -> (a -> b) -> s -> t
(%~) :: Traversal s t a b -> (a -> b) -> s -> t

Data type to be used as a promoted type for MethodStreamingType.

A type class for lens fields.

The instance HasField s x a can be understood as "s has a field named x of type a".

A proto3 field type with an implicit default value.

This is distinct from, say, Data.Default to avoid orphan instances, and because Bool doesn't necessarily have a good Default instance for general usage.

Every protocol buffer is an instance of Message. This class enables serialization by providing reflection of all of the fields that may be used by this type.