Struct BoxCallableOnce 

pub struct BoxCallableOnce<R, E> { /* private fields */ }

Box-based one-time callable.

BoxCallableOnce<R, E> stores a Box<dyn FnOnce() -> Result<R, E>> and can be executed only once. It is the boxed concrete implementation of CallableOnce.

Type Parameters

• R - The success value returned by the computation.
• E - The error value returned when the computation fails.

Examples

use qubit_function::{BoxCallableOnce, CallableOnce};

let task = BoxCallableOnce::new(|| Ok::<i32, String>(42));
assert_eq!(task.call(), Ok(42));

Author

Haixing Hu

Implementations

impl<R, E> BoxCallableOnce<R, E>

pub fn new<F>(function: F) -> Self

where F: FnOnce() -> Result<R, E> + 'static,

Creates a new callable.

Wraps the provided closure in the appropriate smart pointer type for this callable implementation.

pub fn new_with_name<F>(name: &str, function: F) -> Self

where F: FnOnce() -> Result<R, E> + 'static,

Creates a new named callable.

Wraps the provided closure and assigns it a name, which is useful for debugging and logging purposes.

pub fn new_with_optional_name<F>(function: F, name: Option<String>) -> Self

where F: FnOnce() -> Result<R, E> + 'static,

Creates a new named callable with an optional name.

Wraps the provided closure and assigns it an optional name.

pub fn from_supplier<S>(supplier: S) -> Self

where S: SupplierOnce<Result<R, E>> + 'static,

Creates a boxed callable from a one-time supplier.

This is an explicit bridge from SupplierOnce<Result<R, E>> to CallableOnce<R, E>.

Parameters

• supplier - The supplier that produces the callable result.

Returns

A new BoxCallableOnce<R, E>.

pub fn name(&self) -> Option<&str>

Gets the name of this callable.

Returns

Returns Some(&str) if a name was set, None otherwise.

pub fn set_name(&mut self, name: &str)

Sets the name of this callable.

Parameters

• name - The name to set for this callable

pub fn clear_name(&mut self)

Clears the name of this callable.

pub fn map<U, M>(self, mapper: M) -> BoxCallableOnce<U, E>

where M: FnOnce(R) -> U + 'static, R: 'static, E: 'static,

Maps the success value of this callable.

Parameters

• mapper - Function that transforms the success value.

Returns

A new callable that applies mapper when this callable succeeds.

pub fn map_err<E2, M>(self, mapper: M) -> BoxCallableOnce<R, E2>

where M: FnOnce(E) -> E2 + 'static, R: 'static, E: 'static,

Maps the error value of this callable.

Parameters

• mapper - Function that transforms the error value.

Returns

A new callable that applies mapper when this callable fails.

pub fn and_then<U, N>(self, next: N) -> BoxCallableOnce<U, E>

where N: FnOnce(R) -> Result<U, E> + 'static, R: 'static, E: 'static,

Chains another fallible computation after this callable succeeds.

Parameters

• next - Function that receives the success value and returns the next result.

Returns

A new callable that runs next only when this callable succeeds.

Trait Implementations

impl<R, E> CallableOnce<R, E> for BoxCallableOnce<R, E>

fn call(self) -> Result<R, E>

Executes the boxed callable.

fn into_runnable(self) -> BoxRunnableOnce<E>

where Self: Sized + 'static,

Converts this boxed callable into a boxed runnable while preserving its name.

fn into_box(self) -> BoxCallableOnce<R, E>

Converts this callable into a boxed callable.

fn into_fn(self) -> impl FnOnce() -> Result<R, E>

Converts this callable into a closure.

impl<R, E> Debug for BoxCallableOnce<R, E>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<R, E> Display for BoxCallableOnce<R, E>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<R, E> SupplierOnce<Result<R, E>> for BoxCallableOnce<R, E>

fn get(self) -> Result<R, E>

Executes the boxed callable as a one-time supplier of Result<R, E>.

fn into_box(self) -> BoxSupplierOnce<T>

where Self: Sized + 'static,

Converts to BoxSupplierOnce.

fn into_fn(self) -> impl FnOnce() -> T

where Self: Sized + 'static,

Converts the supplier to a Box<dyn FnOnce() -> T>.