Trait Traversable 

pub trait Traversable: Functor + Foldable {
    // Provided methods
    fn traverse<'a, A: 'a + Clone, B: 'a + Clone, F: Applicative, Func>(
        func: Func,
        ta: <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>,
    ) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>>
       where Func: Fn(A) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, B> + 'a,
             <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>: Clone,
             <F as Kind_cdc7cd43dac7585f>::Of<'a, B>: Clone { ... }
    fn sequence<'a, A: 'a + Clone, F: Applicative>(
        ta: <Self as Kind_cdc7cd43dac7585f>::Of<'a, <F as Kind_cdc7cd43dac7585f>::Of<'a, A>>,
    ) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>>
       where <F as Kind_cdc7cd43dac7585f>::Of<'a, A>: Clone,
             <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>: Clone { ... }
}

A type class for traversable functors.

Traversable functors can be traversed, which accumulates results and effects in some Applicative context.

Provided Methods

fn traverse<'a, A: 'a + Clone, B: 'a + Clone, F: Applicative, Func>( func: Func, ta: <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>, ) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>>

where Func: Fn(A) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, B> + 'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, B>: Clone, <F as Kind_cdc7cd43dac7585f>::Of<'a, B>: Clone,

Map each element of the Traversable structure to a computation, evaluate those computations and combine the results into an Applicative context.

The default implementation is defined in terms of sequence and map.

Note: This default implementation may be less efficient than a direct implementation because it performs two passes: first mapping the function to create an intermediate structure of computations, and then sequencing that structure. A direct implementation can often perform the traversal in a single pass without allocating an intermediate container. Types should provide their own implementation if possible.

Type Signature

forall A B F. Applicative F => (A -> F B, Self A) -> F (Self B)

Type Parameters

• 'a: The lifetime of the elements.
• A: The type of the elements in the traversable structure.
• B: The type of the elements in the resulting traversable structure.
• F: The applicative context.
• Func: The type of the function to apply.

Parameters

• func: The function to apply to each element, returning a value in an applicative context.
• ta: The traversable structure.

Returns

The traversable structure wrapped in the applicative context.

Examples

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

let x = Some(5);
let y = traverse::<OptionBrand, _, _, OptionBrand, _>(|a| Some(a * 2), x);
assert_eq!(y, Some(Some(10)));

fn sequence<'a, A: 'a + Clone, F: Applicative>( ta: <Self as Kind_cdc7cd43dac7585f>::Of<'a, <F as Kind_cdc7cd43dac7585f>::Of<'a, A>>, ) -> <F as Kind_cdc7cd43dac7585f>::Of<'a, <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>>

where <F as Kind_cdc7cd43dac7585f>::Of<'a, A>: Clone, <Self as Kind_cdc7cd43dac7585f>::Of<'a, A>: Clone,

Evaluate each computation in a Traversable structure and accumulate the results into an Applicative context.

The default implementation is defined in terms of traverse and identity.

Type Signature

forall A F. Applicative F => Self (F A) -> F (Self A)

Type Parameters

• 'a: The lifetime of the elements.
• A: The type of the elements in the traversable structure.
• F: The applicative context.

Parameters

• ta: The traversable structure containing values in an applicative context.

Returns

The traversable structure wrapped in the applicative context.

Examples

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

let x = Some(Some(5));
let y = sequence::<OptionBrand, _, OptionBrand>(x);
assert_eq!(y, Some(Some(5)));

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Traversable for CatListBrand

impl Traversable for IdentityBrand

impl Traversable for OptionBrand

impl Traversable for Tuple1Brand

impl Traversable for VecBrand

impl<DoneType: Clone + 'static> Traversable for StepWithDoneBrand<DoneType>

Type Parameters

• DoneType: The done type.

impl<E: Clone + 'static> Traversable for ResultWithErrBrand<E>

Type Parameters

• E: The error type.

impl<First: Clone + 'static> Traversable for PairWithFirstBrand<First>

Type Parameters

• First: The type of the first value in the pair.

Type Parameters

• First: The type of the first value in the pair.

impl<First: Clone + 'static> Traversable for Tuple2WithFirstBrand<First>

Type Parameters

• First: The type of the first value in the tuple.

impl<LoopType: Clone + 'static> Traversable for StepWithLoopBrand<LoopType>

Type Parameters

• LoopType: The loop type.

impl<Second: Clone + 'static> Traversable for PairWithSecondBrand<Second>

Type Parameters

• Second: The type of the second value in the pair.

Type Parameters

• Second: The type of the second value in the pair.

impl<Second: Clone + 'static> Traversable for Tuple2WithSecondBrand<Second>

Type Parameters

• Second: The type of the second value in the tuple.

impl<T: Clone + 'static> Traversable for ResultWithOkBrand<T>

Type Parameters

• T: The success type.