The Const functor, defined as Const<'T, 'U> where 'U is a phantom type. Useful for: Lens getters Its applicative instance plays a fundamental role in Lens.
open FSharpPlus
open FSharpPlus.Lens
open FSharpPlus.Data
// note for instance the definition of view (from the Lens part of F#+):
let view (optic: ('a -> Const<_,'b>) -> _ -> Const<_,'t>) (source: 's) : 'a = Const.run (optic Const source)
namespace FSharpPlus
module Lens
from FSharpPlus
<summary>
Lens functions and operators
</summary>
namespace FSharpPlus.Data
val view: optic: (('a -> Const<'a,'b>) -> 's -> Const<'a,'t>) -> source: 's -> 'a
val optic: (('a -> Const<'a,'b>) -> 's -> Const<'a,'t>)
'a
Multiple items
union case Const.Const: 't -> Const<'t,'u>
--------------------
module Const
from FSharpPlus.Data
<summary>
Basic operations on Const
</summary>
--------------------
[<Struct>]
type Const<'t,'u> =
| Const of 't
static member ( *> ) : Const<'C,'T> * Const<'C,'U> -> Const<'C,'U> (requires member ``+``)
static member (+) : Const<'T,'U> * Const<'T,'U> -> Const<'T,'U> (requires member ``+``)
static member (<!>) : ('T -> 'U) * Const<'C,'T> -> Const<'C,'U>
static member ( <* ) : Const<'C,'U> * Const<'C,'T> -> Const<'C,'U> (requires member ``+``)
static member (<*>) : Const<'C,('T -> 'U)> * Const<'C,'T> -> Const<'C,'U> (requires member ``+``)
static member Bifold: Const<'T,'V> * f: ('U -> 'T -> 'U) * ('W -> 'V -> 'W) * z: 'U -> 'U
static member BifoldBack: Const<'T,'V> * f: ('T -> 'U -> 'U) * ('V -> 'W -> 'W) * z: 'U -> 'U
static member BifoldMap: Const<'T,'V> * f: ('T -> 'U) * ('V -> 'W) -> 'U
static member Bimap: Const<'T,'V> * f: ('T -> 'U) * ('V -> 'W) -> Const<'U,'W>
static member Bitraverse: Const<'T1,'U1> * f: ('T1 -> 'Functor<'T2>) * g: ('U1 -> 'Functor<'U2>) -> 'Functor<Const<'T2, 'U2>> (requires member Map and member Map and member Map)
...
<summary> The Const functor, defined as Const<'T, 'U> where 'U is a phantom type. Useful for: Lens getters Its applicative instance plays a fundamental role in Lens.
<para /> Useful for: Lens getters.
<para /> Its applicative instance plays a fundamental role in Lens. </summary>
'b
't
val source: 's
's
val run: Const<'f,'g> -> 'f