Struct BoxConditionalStatefulBiConsumer 

pub struct BoxConditionalStatefulBiConsumer<T, U> { /* private fields */ }

BoxConditionalBiConsumer struct

A conditional bi-consumer that only executes when a predicate is satisfied. Uses BoxStatefulBiConsumer and BoxBiPredicate for single ownership semantics.

This type is typically created by calling BoxStatefulBiConsumer::when() and is designed to work with the or_else() method to create if-then-else logic.

Features

• Single Ownership: Not cloneable, consumes self on use
• Conditional Execution: Only consumes when predicate returns true
• Chainable: Can add or_else branch to create if-then-else logic
• Implements BiConsumer: Can be used anywhere a BiConsumer is expected

Examples

Basic Conditional Execution

use qubit_function::{BiConsumer, BoxStatefulBiConsumer, StatefulBiConsumer};
use std::sync::{Arc, Mutex};

let log = Arc::new(Mutex::new(Vec::new()));
let l = log.clone();
let mut consumer = BoxStatefulBiConsumer::new(move |x: &i32, y: &i32| {
    l.lock().unwrap().push(*x + *y);
});
let mut conditional = consumer.when(|x: &i32, y: &i32| *x > 0 && *y > 0);

conditional.accept(&5, &3);
assert_eq!(*log.lock().unwrap(), vec![8]); // Executed

conditional.accept(&-5, &3);
assert_eq!(*log.lock().unwrap(), vec![8]); // Not executed

With or_else Branch

use qubit_function::{BiConsumer, BoxStatefulBiConsumer, StatefulBiConsumer};
use std::sync::{Arc, Mutex};

let log = Arc::new(Mutex::new(Vec::new()));
let l1 = log.clone();
let l2 = log.clone();
let mut consumer = BoxStatefulBiConsumer::new(move |x: &i32, y: &i32| {
    l1.lock().unwrap().push(*x + *y);
}).when(|x: &i32, y: &i32| *x > 0 && *y > 0)
  .or_else(move |x: &i32, y: &i32| {
    l2.lock().unwrap().push(*x * *y);
});

consumer.accept(&5, &3);
assert_eq!(*log.lock().unwrap(), vec![8]); // when branch executed

consumer.accept(&-5, &3);
assert_eq!(*log.lock().unwrap(), vec![8, -15]); // or_else branch executed

Author

Haixing Hu

Implementations

impl<T, U> BoxConditionalStatefulBiConsumer<T, U>

pub fn and_then<C>(self, next: C) -> BoxStatefulBiConsumer<T, U>

where T: 'static, U: 'static, C: StatefulBiConsumer<T, U> + 'static,

Chains another bi-consumer in sequence

Combines the current conditional bi-consumer with another bi-consumer into a new bi-consumer that implements the following semantics:

When the returned bi-consumer is called with two arguments:

1. First, it checks the predicate of this conditional bi-consumer
2. If the predicate is satisfied, it executes the internal bi-consumer of this conditional bi-consumer
3. Then, regardless of whether the predicate was satisfied, it unconditionally executes the next bi-consumer

In other words, this creates a bi-consumer that conditionally executes the first action (based on the predicate), and then always executes the second action.

Parameters

• next - The next bi-consumer to execute (always executed)

Returns

Returns a new combined bi-consumer

Examples

use std::sync::atomic::{AtomicI32, Ordering};
use qubit_function::BoxBiConsumer;
use qubit_function::BiConsumer;
use std::sync::Arc;

let result = Arc::new(AtomicI32::new(0));
let result1 = result.clone();
let result2 = result.clone();

let consumer1 = BoxBiConsumer::new(move |x: &i32, y: &i32| {
    result1.fetch_add(x + y, Ordering::SeqCst);
});

let consumer2 = BoxBiConsumer::new(move |x: &i32, y: &i32| {
    result2.fetch_add(2 * (x + y), Ordering::SeqCst);
});

let conditional = consumer1.when(|x: &i32, y: &i32| *x > 0 && *y > 0);
let chained = conditional.and_then(consumer2);

chained.accept(&5, &3);  // result = (5+3) + 2*(5+3) = 24
let result3 = result.clone();
result3.store(0, Ordering::SeqCst);  // reset
chained.accept(&-5, &3); // result = 0 + 2*(-5+3) = -4 (not -8!)

pub fn or_else<C>(self, else_consumer: C) -> BoxStatefulBiConsumer<T, U>

where T: 'static, U: 'static, C: StatefulBiConsumer<T, U> + 'static,

Adds an else branch

Executes the original bi-consumer when the condition is satisfied, otherwise executes else_consumer.

Parameters

• else_consumer - The bi-consumer for the else branch

Returns

Returns a new bi-consumer with if-then-else logic

Examples found in repository

examples/consumers/bi_consumer_demo.rs (lines 139-141)

fn main() {
    println!("=== BiConsumer Demo ===\n");

    // 1. BoxBiConsumer - Single ownership
    println!("1. BoxBiConsumer - Single ownership:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let box_consumer = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        println!("  Processing: x={}, y={}", x, y);
        l.lock().unwrap().push(*x + *y);
    });
    box_consumer.accept(&10, &5);
    println!("  Result log: {:?}\n", *log.lock().unwrap());

    // 2. Method chaining with BoxBiConsumer
    println!("2. BoxBiConsumer with method chaining:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let chained = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        l1.lock().unwrap().push(*x + *y);
        println!("  After first operation: sum = {}", x + y);
    })
    .and_then(move |x: &i32, y: &i32| {
        l2.lock().unwrap().push(*x * *y);
        println!("  After second operation: product = {}", x * y);
    });
    chained.accept(&5, &3);
    println!("  Final log: {:?}\n", *log.lock().unwrap());

    // 3. ArcBiConsumer - Thread-safe shared ownership
    println!("3. ArcBiConsumer - Thread-safe shared ownership:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let arc_consumer = ArcBiConsumer::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
        println!("  Thread {:?}: sum = {}", thread::current().id(), x + y);
    });

    let consumer1 = arc_consumer.clone();
    let consumer2 = arc_consumer.clone();

    let handle1 = thread::spawn(move || {
        let c = consumer1;
        c.accept(&10, &5);
    });

    let handle2 = thread::spawn(move || {
        let c = consumer2;
        c.accept(&20, &8);
    });

    handle1.join().unwrap();
    handle2.join().unwrap();
    println!("  Final log: {:?}\n", *log.lock().unwrap());

    // 4. RcBiConsumer - Single-threaded shared ownership
    println!("4. RcBiConsumer - Single-threaded shared ownership:");
    let log = Rc::new(RefCell::new(Vec::new()));
    let l = log.clone();
    let rc_consumer = RcBiConsumer::new(move |x: &i32, y: &i32| {
        l.borrow_mut().push(*x + *y);
    });

    let clone1 = rc_consumer.clone();
    let clone2 = rc_consumer.clone();

    clone1.accept(&5, &3);
    println!("  After first use: {:?}", *log.borrow());

    clone2.accept(&7, &2);
    println!("  After second use: {:?}\n", *log.borrow());

    // 5. Working with closures directly
    println!("5. Working with closures directly:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let closure = move |x: &i32, y: &i32| {
        let sum = *x + *y;
        l.lock().unwrap().push(sum);
    };
    closure.accept(&10, &20);
    println!("  After closure: {:?}\n", *log.lock().unwrap());

    // 6. Conditional BiConsumer
    println!("6. Conditional BiConsumer:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let mut conditional = BoxStatefulBiConsumer::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
    })
    .when(|x: &i32, y: &i32| *x > 0 && *y > 0);

    conditional.accept(&5, &3);
    println!("  Positive values: {:?}", *log.lock().unwrap());

    conditional.accept(&-5, &3);
    println!("  Negative value (unchanged): {:?}\n", *log.lock().unwrap());

    // 7. Conditional branch BiConsumer
    println!("7. Conditional branch BiConsumer:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let mut branch = BoxStatefulBiConsumer::new(move |x: &i32, _y: &i32| {
        l1.lock().unwrap().push(*x);
    })
    .when(|x: &i32, y: &i32| *x > *y)
    .or_else(move |_x: &i32, y: &i32| {
        l2.lock().unwrap().push(*y);
    });

    branch.accept(&15, &10);
    println!("  When x > y: {:?}", *log.lock().unwrap());

    branch.accept(&5, &10);
    println!("  When x <= y: {:?}\n", *log.lock().unwrap());

    // 8. Accumulating statistics
    println!("8. Accumulating statistics:");
    let count = Arc::new(Mutex::new(0));
    let sum = Arc::new(Mutex::new(0));
    let c = count.clone();
    let s = sum.clone();
    let stats_consumer = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        *c.lock().unwrap() += 1;
        *s.lock().unwrap() += x + y;
    });

    stats_consumer.accept(&5, &3);
    stats_consumer.accept(&10, &2);
    stats_consumer.accept(&7, &8);

    println!("  Count: {}", *count.lock().unwrap());
    println!("  Sum: {}\n", *sum.lock().unwrap());

    // 9. Name support
    println!("9. Name support:");
    let mut named_consumer = BoxBiConsumer::<i32, i32>::noop();
    println!("  Initial name: {:?}", named_consumer.name());

    named_consumer.set_name("sum_calculator");
    println!("  After setting name: {:?}", named_consumer.name());
    println!("  Display: {}\n", named_consumer);

    println!("=== Demo Complete ===");
}

Trait Implementations

impl<T, U> Debug for BoxConditionalStatefulBiConsumer<T, U>

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

Formats the value using the given formatter.

impl<T, U> Display for BoxConditionalStatefulBiConsumer<T, U>

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

Formats the value using the given formatter.

impl<T, U> StatefulBiConsumer<T, U> for BoxConditionalStatefulBiConsumer<T, U>

fn accept(&mut self, first: &T, second: &U)

Performs the consumption operation

fn into_box(self) -> BoxStatefulBiConsumer<T, U>

where Self: 'static,

Converts to BoxStatefulBiConsumer

fn into_rc(self) -> RcStatefulBiConsumer<T, U>

where Self: 'static,

Converts to RcStatefulBiConsumer

fn into_fn(self) -> impl FnMut(&T, &U)

Converts bi-consumer to a closure

fn into_arc(self) -> ArcStatefulBiConsumer<T, U>

where Self: Sized + Send + 'static,

Converts to ArcStatefulBiConsumer

fn into_once(self) -> BoxBiConsumerOnce<T, U>

where Self: Sized + 'static,

Convert to BiConsumerOnce