Trait RefWitherable

Source

pub trait RefWitherable:
    RefFilterable
    + RefTraversable
    + Kind_cdc7cd43dac7585f {
    // Provided methods
    fn ref_wilt<'a, FnBrand, M: Applicative, A: 'a + Clone, E: 'a + Clone, O: 'a + Clone>(
        func: impl Fn(&A) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>> + 'a,
        ta: &<Self as Kind_cdc7cd43dac7585f>::Of<'a, A>,
    ) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, (<Self as Kind_cdc7cd43dac7585f>::Of<'a, E>, <Self as Kind_cdc7cd43dac7585f>::Of<'a, O>)>
       where FnBrand: LiftFn + 'a,
             <Self as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>>: Clone,
             <M as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>>: Clone { ... }
    fn ref_wither<'a, FnBrand, M: Applicative, A: 'a + Clone, B: 'a + Clone>(
        func: impl Fn(&A) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>> + 'a,
        ta: &<Self as Kind_cdc7cd43dac7585f>::Of<'a, A>,
    ) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>>
       where FnBrand: LiftFn + 'a,
             <Self as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>>: Clone,
             <M as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>>: Clone { ... }
}

Expand description

By-reference withering (effectful filtering) of structures.

Similar to Witherable, but closures receive &A instead of A. Combines by-reference traversal with filtering in an applicative context.

Default implementations derive:

ref_wilt from ref_traverse + separate.
ref_wither from ref_traverse + compact.

Provided Methods§

Source

fn ref_wilt<'a, FnBrand, M: Applicative, A: 'a + Clone, E: 'a + Clone, O: 'a + Clone>( func: impl Fn(&A) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>> + 'a, ta: &<Self as Kind_cdc7cd43dac7585f>::Of<'a, A>, ) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, (<Self as Kind_cdc7cd43dac7585f>::Of<'a, E>, <Self as Kind_cdc7cd43dac7585f>::Of<'a, O>)>
where FnBrand: LiftFn + 'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>>: Clone, <M as Kind_cdc7cd43dac7585f>::Of<'a, Result<O, E>>: Clone,

Partitions by reference in an applicative context.

Maps each element by reference to a computation producing Result<O, E>, traverses the structure, then separates the results.

§Type Signature

forall M A E O. Applicative M => (&A -> M (Result O E), &Self A) -> M (Self E, Self O)

§Type Parameters

'a: The lifetime of the elements.
FnBrand: The brand of the cloneable function wrapper.
M: The applicative context.
A: The type of the input elements.
E: The error type.
O: The success type.

§Parameters

func: The function to apply to each element reference.
ta: The structure to partition.

§Returns

The partitioned structure in the applicative context.

§Examples

use fp_library::{
	brands::*,
	functions::explicit::*,
};

let v = vec![1, 2, 3, 4, 5];
let result: Option<(Vec<i32>, Vec<i32>)> =
	wilt::<RcFnBrand, VecBrand, OptionBrand, _, _, _, _, _>(
		|x: &i32| Some(if *x > 3 { Ok(*x) } else { Err(*x) }),
		&v,
	);
assert_eq!(result, Some((vec![1, 2, 3], vec![4, 5])));

Source

fn ref_wither<'a, FnBrand, M: Applicative, A: 'a + Clone, B: 'a + Clone>( func: impl Fn(&A) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>> + 'a, ta: &<Self as Kind_cdc7cd43dac7585f>::Of<'a, A>, ) -> <M as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>>
where FnBrand: LiftFn + 'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>>: Clone, <M as Kind_cdc7cd43dac7585f>::Of<'a, Option<B>>: Clone,

Filters by reference in an applicative context.

Maps each element by reference to a computation producing Option<B>, traverses the structure, then compacts the results.

§Type Signature

forall M A B. Applicative M => (&A -> M (Option B), &Self A) -> M (Self B)

§Type Parameters

'a: The lifetime of the elements.
FnBrand: The brand of the cloneable function wrapper.
M: The applicative context.
A: The type of the input elements.
B: The type of the output elements.

§Parameters

func: The function to apply to each element reference.
ta: The structure to filter.

§Returns

The filtered structure in the applicative context.

§Examples

use fp_library::{
	brands::*,
	functions::explicit::*,
};

let v = vec![1, 2, 3, 4, 5];
let result: Option<Vec<i32>> = wither::<RcFnBrand, VecBrand, OptionBrand, _, _, _, _>(
	|x: &i32| if *x > 3 { Some(Some(*x)) } else { Some(None) },
	&v,
);
assert_eq!(result, Some(vec![4, 5]));