Struct Stall 

pub struct Stall<'a, FunctionBrand: CloneableFn, A: 'a, B: 'a, S: 'a, T: 'a> {
    pub get: <FunctionBrand as CloneableFn>::Of<'a, S, Result<A, T>>,
    pub set: <FunctionBrand as CloneableFn>::Of<'a, (S, B), T>,
}

The Stall profunctor.

Type Parameters

• 'a: The lifetime of the functions.
• FunctionBrand: The cloneable function brand.
• A: The type of the value produced by the preview function.
• B: The type of the value consumed by the setter.
• S: The source type of the structure.
• T: The target type of the structure.

Fields

get: <FunctionBrand as CloneableFn>::Of<'a, S, Result<A, T>>

Preview function: tries to extract the focus.

set: <FunctionBrand as CloneableFn>::Of<'a, (S, B), T>

Setter function.

Implementations

impl<'a, FunctionBrand: CloneableFn, A: 'a, B: 'a, S: 'a, T: 'a> Stall<'a, FunctionBrand, A, B, S, T>

Type Parameters

• 'a: The lifetime of the functions.
• FunctionBrand: The cloneable function brand.
• A: The type of the value produced by the preview function.
• B: The type of the value consumed by the setter.
• S: The source type of the structure.
• T: The target type of the structure.

pub fn new( get: <FunctionBrand as CloneableFn>::Of<'a, S, Result<A, T>>, set: <FunctionBrand as CloneableFn>::Of<'a, (S, B), T>, ) -> Self

Creates a new Stall instance.

Type Signature

forall A B S T. (S -> Result A T, (S, B) -> T) -> Stall FunctionBrand A B S T

Parameters

• get: The preview function.
• set: The setter function.

Returns

A new instance of the type.

Examples

use fp_library::{
	brands::RcFnBrand,
	classes::cloneable_fn::new as cloneable_fn_new,
	types::optics::Stall,
};

let stall = Stall::<RcFnBrand, i32, i32, (i32, i32), (i32, i32)>::new(
	cloneable_fn_new::<RcFnBrand, _, _>(|s: (i32, i32)| Ok(s.0)),
	cloneable_fn_new::<RcFnBrand, _, _>(|(s, b): ((i32, i32), i32)| (b, s.1)),
);
assert_eq!((stall.get)((10, 20)), Ok(10));
assert_eq!((stall.set)(((10, 20), 30)), (30, 20));