Trait Tester 

pub trait Tester {
    // Required method
    fn test(&self) -> bool;

    // Provided methods
    fn into_box(self) -> BoxTester
       where Self: Sized + 'static { ... }
    fn into_rc(self) -> RcTester
       where Self: Sized + 'static { ... }
    fn into_arc(self) -> ArcTester
       where Self: Sized + Send + Sync + 'static { ... }
    fn into_fn(self) -> impl Fn() -> bool
       where Self: Sized + 'static { ... }
    fn to_box(&self) -> BoxTester
       where Self: Clone + 'static { ... }
    fn to_rc(&self) -> RcTester
       where Self: Clone + 'static { ... }
    fn to_arc(&self) -> ArcTester
       where Self: Clone + Send + Sync + 'static { ... }
    fn to_fn(&self) -> impl Fn() -> bool
       where Self: Clone + 'static { ... }
}

Tests whether a state or condition holds

Tester is a functional abstraction for testing states or conditions. It accepts no parameters and returns a boolean value indicating the test result of some state or condition.

Core Characteristics

• No input parameters: Captures context through closures
• Returns boolean: Indicates test results
• Uses &self: Does not modify its own state, only reads external state
• Repeatable calls: The same Tester can call test() multiple times

Use Cases

• State checking: Check system or service status
• Condition waiting: Repeatedly check until conditions are met
• Health monitoring: Check system health status
• Precondition validation: Verify conditions before operations

Design Philosophy

Tester’s responsibility is “test judgment”, not “state management”. State management is the caller’s responsibility. Tester only reads state and returns judgment results.

Examples

use prism3_function::{BoxTester, Tester};
use std::sync::{Arc, atomic::{AtomicBool, Ordering}};

// State managed externally
let ready = Arc::new(AtomicBool::new(false));
let ready_clone = Arc::clone(&ready);

// Tester only responsible for reading state
let tester = BoxTester::new(move || {
    ready_clone.load(Ordering::Acquire)
});

// Can be called multiple times
assert!(!tester.test());
ready.store(true, Ordering::Release);
assert!(tester.test());

Author

Hu Haixing

Required Methods

fn test(&self) -> bool

Executes the test and returns the test result

This method can be called multiple times without modifying the Tester’s own state.

Return Value

Returns true if the condition holds, otherwise returns false

Examples

use prism3_function::{BoxTester, Tester};

let tester = BoxTester::new(|| true);
assert!(tester.test());

Provided Methods

fn into_box(self) -> BoxTester

where Self: Sized + 'static,

Converts this tester to BoxTester

Return Value

A BoxTester that wraps this tester

Examples

use prism3_function::{Tester, BoxTester};

let closure = || true;
let boxed: BoxTester = closure.into_box();

fn into_rc(self) -> RcTester

where Self: Sized + 'static,

Converts this tester to RcTester

Return Value

A RcTester that wraps this tester

Examples

use prism3_function::{Tester, RcTester};

let closure = || true;
let rc: RcTester = closure.into_rc();

fn into_arc(self) -> ArcTester

where Self: Sized + Send + Sync + 'static,

Converts this tester to ArcTester

Return Value

An ArcTester that wraps this tester

Examples

use prism3_function::{Tester, ArcTester};

let closure = || true;
let arc: ArcTester = closure.into_arc();

fn into_fn(self) -> impl Fn() -> bool

where Self: Sized + 'static,

Converts this tester to a boxed function pointer

Return Value

A Box<dyn Fn() -> bool> that wraps this tester

Examples

use prism3_function::Tester;

let closure = || true;
let func = closure.into_fn();
assert!(func());

fn to_box(&self) -> BoxTester

where Self: Clone + 'static,

Clones and converts this tester to BoxTester

Return Value

A BoxTester that wraps a clone of this tester

Examples

use prism3_function::{Tester, BoxTester, ArcTester};

let arc = ArcTester::new(|| true);
let boxed: BoxTester = arc.to_box();
// arc is still available

fn to_rc(&self) -> RcTester

where Self: Clone + 'static,

Clones and converts this tester to RcTester

Return Value

A RcTester that wraps a clone of this tester

Examples

use prism3_function::{Tester, RcTester, ArcTester};

let arc = ArcTester::new(|| true);
let rc: RcTester = arc.to_rc();
// arc is still available

fn to_arc(&self) -> ArcTester

where Self: Clone + Send + Sync + 'static,

Clones and converts this tester to ArcTester

Return Value

An ArcTester that wraps a clone of this tester

Examples

use prism3_function::{Tester, ArcTester, RcTester};

let rc = RcTester::new(|| true);
// Note: This will panic for RcTester as it's not Send + Sync
// let arc: ArcTester = rc.to_arc();

fn to_fn(&self) -> impl Fn() -> bool

where Self: Clone + 'static,

Clones and converts this tester to a boxed function pointer

Return Value

A Box<dyn Fn() -> bool> that wraps a clone of this tester

Examples

use prism3_function::{Tester, ArcTester};

let arc = ArcTester::new(|| true);
let func = arc.to_fn();
// arc is still available
assert!(func());

Implementors

impl Tester for ArcTester

impl Tester for BoxTester

impl Tester for RcTester

impl<F> Tester for F

where F: Fn() -> bool,