Struct BoxConditionalBiConsumerOnce 

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

BoxConditionalBiConsumerOnce struct

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

This type is typically created by calling BoxBiConsumerOnce::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 BiConsumerOnce: Can be used anywhere a BiConsumerOnce is expected

Examples

Basic Conditional Execution

use prism3_function::{BiConsumerOnce, BoxBiConsumerOnce};
use std::sync::{Arc, Mutex};

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

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

With or_else Branch

use prism3_function::{BiConsumerOnce, BoxBiConsumerOnce};
use std::sync::{Arc, Mutex};

let log = Arc::new(Mutex::new(Vec::new()));
let l1 = log.clone();
let l2 = log.clone();
let consumer = BoxBiConsumerOnce::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_once(&5, &3);
assert_eq!(*log.lock().unwrap(), vec![8]); // when branch executed

Author

Haixing Hu

Implementations

impl<T, U> BoxConditionalBiConsumerOnce<T, U>

where T: 'static, U: 'static,

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

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

Chains another consumer in sequence

Combines the current conditional consumer with another consumer into a new consumer. The current conditional consumer executes first, followed by the next consumer.

Parameters

• next - The next consumer to execute. Note: This parameter is passed by value and will transfer ownership. Since BoxBiConsumerOnce cannot be cloned, the parameter will be consumed. Can be:
  • A closure: |x: &T, y: &U|
  • A BoxBiConsumerOnce<T, U>
  • Any type implementing BiConsumerOnce<T, U>

Returns

Returns a new BoxBiConsumerOnce<T, U>

Examples

use prism3_function::{BiConsumerOnce, BoxBiConsumerOnce};
use std::sync::{Arc, Mutex};

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

// Both cond and second are moved and consumed
let chained = cond.and_then(second);
chained.accept_once(&5, &3);
assert_eq!(*log.lock().unwrap(), vec![8, 15]);
// cond.accept(&2, &3); // Would not compile - moved
// second.accept(&2, &3); // Would not compile - moved

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

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

Adds an else branch

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

Parameters

• else_consumer - The consumer for the else branch. Note: This parameter is passed by value and will transfer ownership. Since BoxBiConsumerOnce cannot be cloned, the parameter will be consumed. Can be:
  • A closure: |x: &T, y: &U|
  • A BoxBiConsumerOnce<T, U>
  • Any type implementing BiConsumerOnce<T, U>

Returns

Returns the composed BoxBiConsumerOnce<T, U>

Examples

Using a closure (recommended)

use prism3_function::{BiConsumerOnce, BoxBiConsumerOnce};
use std::sync::{Arc, Mutex};

let log = Arc::new(Mutex::new(Vec::new()));
let l1 = log.clone();
let l2 = log.clone();
let consumer = BoxBiConsumerOnce::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_once(&5, &3);
assert_eq!(*log.lock().unwrap(), vec![8]); // Condition satisfied

Examples found in repository

examples/bi_consumer_once_demo.rs (lines 79-81)

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

    // 1. Basic usage
    println!("1. Basic usage:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let consumer = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
        println!("  Sum: {}", x + y);
    });
    consumer.accept_once(&10, &5);
    println!("  Log: {:?}\n", *log.lock().unwrap());

    // 2. Method chaining
    println!("2. Method chaining:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let chained = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        l1.lock().unwrap().push(*x + *y);
        println!("  First: sum={}", x + y);
    })
    .and_then(move |x: &i32, y: &i32| {
        l2.lock().unwrap().push(*x * *y);
        println!("  Second: product={}", x * y);
    });
    chained.accept_once(&5, &3);
    println!("  Log: {:?}\n", *log.lock().unwrap());

    // 3. Conditional execution - true case
    println!("3. Conditional execution - true case:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let conditional = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
    })
    .when(|x: &i32, y: &i32| *x > 0 && *y > 0);
    conditional.accept_once(&5, &3);
    println!("  Positive values: {:?}\n", *log.lock().unwrap());

    // 4. Conditional execution - false case
    println!("4. Conditional execution - false case:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let conditional = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
    })
    .when(|x: &i32, y: &i32| *x > 0 && *y > 0);
    conditional.accept_once(&-5, &3);
    println!("  Negative value (unchanged): {:?}\n", *log.lock().unwrap());

    // 5. Conditional branching
    println!("5. Conditional branching:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let branch = BoxBiConsumerOnce::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_once(&15, &10);
    println!("  When x > y: {:?}\n", *log.lock().unwrap());

    // 6. Working with closures directly
    println!("6. Working with closures directly:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let closure = move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
        println!("  Processed: {}", x + y);
    };
    closure.accept_once(&10, &20);
    println!("  Log: {:?}\n", *log.lock().unwrap());

    // 7. Moving captured values
    println!("7. Moving captured values:");
    let data = vec![1, 2, 3, 4, 5];
    let consumer = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        println!("  x={}, y={}", x, y);
        println!("  Captured data: {:?}", data);
        println!("  Data sum: {}", data.iter().sum::<i32>());
    });
    consumer.accept_once(&5, &3);
    // data is no longer available here
    println!();

    // 8. Initialization callback
    println!("8. Initialization callback:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let init_callback = BoxBiConsumerOnce::new(move |width: &i32, height: &i32| {
        println!("  Initializing with dimensions: {}x{}", width, height);
        l.lock().unwrap().push(*width * *height);
    });
    init_callback.accept_once(&800, &600);
    println!("  Areas: {:?}\n", *log.lock().unwrap());

    // 9. Cleanup callback
    println!("9. Cleanup callback:");
    let cleanup = BoxBiConsumerOnce::new(|count: &i32, total: &i32| {
        println!("  Cleanup: processed {} out of {} items", count, total);
        println!(
            "  Success rate: {:.1}%",
            (*count as f64 / *total as f64) * 100.0
        );
    });
    cleanup.accept_once(&85, &100);
    println!();

    // 10. Name support
    println!("10. Name support:");
    let mut named_consumer = BoxBiConsumerOnce::<i32, i32>::noop();
    println!("  Initial name: {:?}", named_consumer.name());

    named_consumer.set_name("init_callback");
    println!("  After setting name: {:?}", named_consumer.name());
    println!("  Display: {}", named_consumer);
    named_consumer.accept_once(&1, &2);
    println!();

    // 11. Print helpers
    println!("11. Print helpers:");
    let print = BoxBiConsumerOnce::new(|x: &i32, y: &i32| println!("{}, {}", x, y));
    print.accept_once(&42, &10);

    let print_with =
        BoxBiConsumerOnce::new(|x: &i32, y: &i32| println!("Dimensions: {}, {}", x, y));
    print_with.accept_once(&800, &600);
    println!();

    // 12. Converting to function
    println!("12. Converting to function:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let consumer = BoxBiConsumerOnce::new(move |x: &i32, y: &i32| {
        l.lock().unwrap().push(*x + *y);
    });
    let func = consumer.into_fn_once();
    func(&7, &3);
    println!("  Log: {:?}\n", *log.lock().unwrap());

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

Trait Implementations

impl<T, U> BiConsumerOnce<T, U> for BoxConditionalBiConsumerOnce<T, U>

where T: 'static, U: 'static,

fn accept_once(self, first: &T, second: &U)

Performs the one-time consumption operation

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

Converts to BoxBiConsumerOnce

fn into_fn_once(self) -> impl FnOnce(&T, &U)

Converts to a closure