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 { ... }
}Expand description
A type class for traversable functors.
Traversable functors can be traversed, which accumulates results and effects in some Applicative context.
Provided Methods§
Sourcefn 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 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 self a b f. (Traversable self, 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)));Sourcefn 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,
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 self a f. (Traversable self, 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.