Struct BoxCallable 

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

Box-based one-time callable.

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

Type Parameters

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

Examples

use qubit_function::{BoxCallable, Callable};

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

Author

Haixing Hu

Implementations

impl<R, E> BoxCallable<R, E>

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

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

Creates a new boxed callable.

Parameters

• function - The one-time closure executed by this callable.

Returns

A new unnamed BoxCallable<R, E>.

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

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

Creates a new named boxed callable.

Parameters

• name - Name used by Debug and Display.
• function - The one-time closure executed by this callable.

Returns

A new named BoxCallable<R, E>.

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

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

Creates a new boxed callable with an optional name.

Parameters

• function - The one-time closure executed by this callable.
• name - Optional name used by Debug and Display.

Returns

A new BoxCallable<R, E>.

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 Callable<R, E>.

Parameters

• supplier - The supplier that produces the callable result.

Returns

A new BoxCallable<R, E>.

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

Gets the optional callable name.

Returns

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

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

Sets the callable name.

Parameters

• name - The new name.

pub fn clear_name(&mut self)

Clears the callable name.

pub fn map<U, M>(self, mapper: M) -> BoxCallable<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) -> BoxCallable<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) -> BoxCallable<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> Callable<R, E> for BoxCallable<R, E>

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

Executes the boxed callable.

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

Returns this boxed callable without re-boxing it.

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

Extracts the underlying one-time closure.

fn into_runnable(self) -> BoxRunnable<E>

where Self: Sized + 'static,

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

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

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

Formats this boxed callable for debugging.

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

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

Formats this boxed callable for display.

impl<R, E> SupplierOnce<Result<R, E>> for BoxCallable<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>.