Struct ArcTransformer 

pub struct ArcTransformer<T, R> { /* private fields */ }

ArcTransformer - thread-safe transformer wrapper

A thread-safe, clonable transformer wrapper suitable for multi-threaded scenarios. Can be called multiple times and shared across threads.

Features

• Based on: Arc<dyn Fn(T) -> R + Send + Sync>
• Ownership: Shared ownership via reference counting
• Reusability: Can be called multiple times (each call consumes its input)
• Thread Safety: Thread-safe (Send + Sync required)
• Clonable: Cheap cloning via Arc::clone

Author

Haixing Hu

Implementations

impl<T, R> ArcTransformer<T, R>

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

where F: Fn(T) -> R + Send + Sync + 'static,

Creates a new transformer.

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

Examples found in repository

examples/transformers/transformer_once_demo.rs (line 68)

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

    // BoxTransformer TransformerOnce demonstration
    println!("1. BoxTransformer TransformerOnce demonstration:");
    let double = BoxTransformer::new(|x: i32| x * 2);
    let result = double.apply(21);
    println!("   double.apply(21) = {}", result);

    // Convert to BoxTransformerOnce
    let double = BoxTransformer::new(|x: i32| x * 2);
    let boxed = double.into_box();
    let result = boxed.apply(21);
    println!("   double.into_box().apply(21) = {}", result);

    // Convert to function
    let double = BoxTransformer::new(|x: i32| x * 2);
    let func = double.into_fn();
    let result = func(21);
    println!("   double.into_fn()(21) = {}", result);

    println!();

    // RcTransformer TransformerOnce demonstration
    println!("2. RcTransformer TransformerOnce demonstration:");
    let uppercase = RcTransformer::new(|s: String| s.to_uppercase());
    let result = uppercase.apply("hello".to_string());
    println!("   uppercase.apply(\"hello\") = {}", result);

    // Use after cloning
    let uppercase = RcTransformer::new(|s: String| s.to_uppercase());
    let uppercase_clone = uppercase.clone();
    let result1 = uppercase.apply("world".to_string());
    let result2 = uppercase_clone.apply("rust".to_string());
    println!("   uppercase.apply(\"world\") = {}", result1);
    println!("   uppercase_clone.apply(\"rust\") = {}", result2);

    println!();

    // ArcTransformer TransformerOnce demonstration
    println!("3. ArcTransformer TransformerOnce demonstration:");
    let parse_and_double = ArcTransformer::new(|s: String| s.parse::<i32>().unwrap_or(0) * 2);
    let result = parse_and_double.apply("21".to_string());
    println!("   parse_and_double.apply(\"21\") = {}", result);

    // Thread safety demonstration
    println!("4. ArcTransformer thread safety demonstration:");
    let double = ArcTransformer::new(|x: i32| x * 2);
    let double_arc = Arc::new(double);
    let _double_clone = Arc::clone(&double_arc);

    let handle = thread::spawn(move || {
        // Create a new transformer in the thread to demonstrate thread safety
        let new_double = ArcTransformer::new(|x: i32| x * 2);
        new_double.apply(21)
    });

    let result = handle.join().unwrap();
    println!("   Executed in thread: new_double.apply(21) = {}", result);

    println!("\n=== Demo completed ===");
}

examples/transformers/transformer_demo.rs (line 42)

fn main() {
    println!("=== Transformer Demo - Type Transformation (consumes T) ===\n");

    // ====================================================================
    // Part 1: BoxTransformer - Single ownership, reusable
    // ====================================================================
    println!("--- BoxTransformer ---");
    let double = BoxTransformer::new(|x: i32| x * 2);
    println!("double.apply(21) = {}", double.apply(21));
    println!("double.apply(42) = {}", double.apply(42));

    // Identity and constant
    let identity = BoxTransformer::<i32, i32>::identity();
    println!("identity.apply(42) = {}", identity.apply(42));

    let constant = BoxTransformer::constant("hello");
    println!("constant.apply(123) = {}", constant.apply(123));
    println!();

    // ====================================================================
    // Part 2: ArcTransformer - Thread-safe, cloneable
    // ====================================================================
    println!("--- ArcTransformer ---");
    let arc_double = ArcTransformer::new(|x: i32| x * 2);
    let arc_cloned = arc_double.clone();

    println!("arc_double.apply(21) = {}", arc_double.apply(21));
    println!("arc_cloned.apply(42) = {}", arc_cloned.apply(42));

    // Multi-threaded usage
    let for_thread = arc_double.clone();
    let handle = thread::spawn(move || for_thread.apply(100));
    println!(
        "In main thread: arc_double.apply(50) = {}",
        arc_double.apply(50)
    );
    println!("In child thread: result = {}", handle.join().unwrap());
    println!();

    // ====================================================================
    // Part 3: RcTransformer - Single-threaded, cloneable
    // ====================================================================
    println!("--- RcTransformer ---");
    let rc_double = RcTransformer::new(|x: i32| x * 2);
    let rc_cloned = rc_double.clone();

    println!("rc_double.apply(21) = {}", rc_double.apply(21));
    println!("rc_cloned.apply(42) = {}", rc_cloned.apply(42));
    println!();

    // ====================================================================
    // Part 4: Practical Examples
    // ====================================================================
    println!("=== Practical Examples ===\n");

    // Example 1: String transformation
    println!("--- String Transformation ---");
    let to_upper = BoxTransformer::new(|s: String| s.to_uppercase());
    println!(
        "to_upper.apply('hello') = {}",
        to_upper.apply("hello".to_string())
    );
    println!(
        "to_upper.apply('world') = {}",
        to_upper.apply("world".to_string())
    );
    println!();

    // Example 2: Type conversion pipeline
    println!("--- Type Conversion Pipeline ---");
    let parse_int = BoxTransformer::new(|s: String| s.parse::<i32>().unwrap_or(0));
    let double_int = BoxTransformer::new(|x: i32| x * 2);
    let to_string = BoxTransformer::new(|x: i32| x.to_string());

    let pipeline = parse_int.and_then(double_int).and_then(to_string);
    println!(
        "pipeline.apply('21') = {}",
        pipeline.apply("21".to_string())
    );
    println!();

    // Example 3: Shared transformation logic
    println!("--- Shared Transformation Logic ---");
    let square = ArcTransformer::new(|x: i32| x * x);

    // Can be shared across different parts of the program
    let transformer1 = square.clone();
    let transformer2 = square.clone();

    println!("transformer1.apply(5) = {}", transformer1.apply(5));
    println!("transformer2.apply(7) = {}", transformer2.apply(7));
    println!("square.apply(3) = {}", square.apply(3));
    println!();

    // Example 4: Transformer registry
    println!("--- Transformer Registry ---");
    let mut transformers: HashMap<String, RcTransformer<i32, String>> = HashMap::new();

    transformers.insert(
        "double".to_string(),
        RcTransformer::new(|x: i32| format!("Doubled: {}", x * 2)),
    );
    transformers.insert(
        "square".to_string(),
        RcTransformer::new(|x: i32| format!("Squared: {}", x * x)),
    );

    if let Some(transformer) = transformers.get("double") {
        println!("Transformer 'double': {}", transformer.apply(7));
    }
    if let Some(transformer) = transformers.get("square") {
        println!("Transformer 'square': {}", transformer.apply(7));
    }
    println!();

    // ====================================================================
    // Part 5: Trait Usage
    // ====================================================================
    println!("=== Trait Usage ===\n");

    fn apply_transformer<F: Transformer<i32, String>>(f: &F, x: i32) -> String {
        f.apply(x)
    }

    let to_string = BoxTransformer::new(|x: i32| format!("Value: {}", x));
    println!("Via trait: {}", apply_transformer(&to_string, 42));

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

examples/transformers/transformer_once_specialized_methods_demo.rs (line 33)

fn main() {
    println!("=== TransformerOnce Specialized Methods Demo ===\n");

    // ============================================================================
    // ArcTransformer TransformerOnce specialized methods
    // ============================================================================

    println!("1. ArcTransformer TransformerOnce specialized methods:");

    let arc_double = ArcTransformer::new(|x: i32| x * 2);

    // Test into_box - consumes self
    let boxed_once = arc_double.clone().into_box();
    println!("   ArcTransformer::into_box(): {}", boxed_once.apply(21));

    // Test into_fn - consumes self
    let fn_once = arc_double.clone().into_fn();
    println!("   ArcTransformer::into_fn(): {}", fn_once(21));

    // Test to_box - borrows self
    let boxed_once_borrowed = arc_double.to_box();
    println!(
        "   ArcTransformer::to_box(): {}",
        boxed_once_borrowed.apply(21)
    );

    // Test to_fn - borrows self
    let fn_once_borrowed = arc_double.to_fn();
    println!("   ArcTransformer::to_fn(): {}", fn_once_borrowed(21));

    // Original transformer still usable after to_xxx methods
    println!(
        "   Original ArcTransformer still works: {}",
        arc_double.apply(21)
    );

    println!();

    // ============================================================================
    // RcTransformer TransformerOnce specialized methods
    // ============================================================================

    println!("2. RcTransformer TransformerOnce specialized methods:");

    let rc_triple = RcTransformer::new(|x: i32| x * 3);

    // Test into_box - consumes self
    let boxed_once = rc_triple.clone().into_box();
    println!("   RcTransformer::into_box(): {}", boxed_once.apply(14));

    // Test into_fn - consumes self
    let fn_once = rc_triple.clone().into_fn();
    println!("   RcTransformer::into_fn(): {}", fn_once(14));

    // Test to_box - borrows self
    let boxed_once_borrowed = rc_triple.to_box();
    println!(
        "   RcTransformer::to_box(): {}",
        boxed_once_borrowed.apply(14)
    );

    // Test to_fn - borrows self
    let fn_once_borrowed = rc_triple.to_fn();
    println!("   RcTransformer::to_fn(): {}", fn_once_borrowed(14));

    // Original transformer still usable after to_xxx methods
    println!(
        "   Original RcTransformer still works: {}",
        rc_triple.apply(14)
    );

    println!();

    // ============================================================================
    // Comparison with default implementations
    // ============================================================================

    println!("3. Performance comparison (specialized vs default):");

    let arc_square = ArcTransformer::new(|x: i32| x * x);

    // Using specialized method (more efficient)
    let specialized_box = arc_square.clone().into_box();
    println!("   Specialized into_box: {}", specialized_box.apply(5));

    // Using default implementation (less efficient)
    let default_box = arc_square.clone().into_box();
    println!("   Default into_box: {}", default_box.apply(5));

    println!();

    // ============================================================================
    // Thread safety demonstration for ArcTransformer
    // ============================================================================

    println!("4. Thread safety with ArcTransformer:");

    let arc_shared = ArcTransformer::new(|x: i32| x + 100);

    // Clone for thread safety
    let arc_clone = arc_shared.clone();

    // Use in different thread context (simulated)
    let handle = std::thread::spawn(move || {
        let boxed = arc_clone.into_box();
        boxed.apply(50)
    });

    let result = handle.join().unwrap();
    println!("   Thread-safe ArcTransformer result: {}", result);

    // Original still usable
    println!(
        "   Original ArcTransformer still works: {}",
        arc_shared.apply(50)
    );

    println!();

    // ============================================================================
    // String transformation example
    // ============================================================================

    println!("5. String transformation with specialized methods:");

    let arc_uppercase = ArcTransformer::new(|s: String| s.to_uppercase());

    // Test with string input
    let test_string = "hello world".to_string();

    // Using specialized methods
    let boxed_upper = arc_uppercase.clone().into_box();
    let result = boxed_upper.apply(test_string.clone());
    println!(
        "   String transformation: '{}' -> '{}'",
        test_string, result
    );

    // Using to_xxx methods (borrowing)
    let fn_upper = arc_uppercase.to_fn();
    let result2 = fn_upper(test_string.clone());
    println!(
        "   String transformation (borrowed): '{}' -> '{}'",
        test_string, result2
    );

    // Original still usable
    println!(
        "   Original ArcTransformer still works: '{}'",
        arc_uppercase.apply(test_string)
    );

    println!("\n=== Demo completed successfully! ===");
}

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

where F: Fn(T) -> R + Send + Sync + 'static,

Creates a new named transformer.

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

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

where F: Fn(T) -> R + Send + Sync + 'static,

Creates a new named transformer with an optional name.

Wraps the provided closure and assigns it an optional name.

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

Gets the name of this transformer.

Returns

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

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

Sets the name of this transformer.

Parameters

• name - The name to set for this transformer

pub fn clear_name(&mut self)

Clears the name of this transformer.

pub fn identity() -> ArcTransformer<T, T>

Creates an identity transformer.

Creates a transformer that returns the input value unchanged. Useful for default values or placeholder implementations.

Returns

Returns a new transformer instance that returns the input unchanged.

pub fn when<P>(&self, predicate: P) -> ArcConditionalTransformer<T, R>

where T: 'static, R: 'static, P: Predicate<T> + Send + Sync + 'static,

pub fn and_then<S, F>(&self, after: F) -> ArcTransformer<T, S>

where T: 'static, R: 'static, S: 'static, F: Transformer<R, S> + Send + Sync + 'static,

impl<T, R> ArcTransformer<T, R>

pub fn constant(value: R) -> ArcTransformer<T, R>

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

Creates a constant transformer

Examples

/// rust /// use qubit_function::{ArcTransformer, Transformer}; /// /// let constant = ArcTransformer::constant("hello"); /// assert_eq!(constant.apply(123), "hello"); ///

Trait Implementations

impl<T, R> Clone for ArcTransformer<T, R>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T, R> Debug for ArcTransformer<T, R>

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

Formats the value using the given formatter.

impl<T, R> Display for ArcTransformer<T, R>

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

Formats the value using the given formatter.

impl<T, R> Transformer<T, R> for ArcTransformer<T, R>

fn apply(&self, input: T) -> R

Applies the transformation to the input value to produce an output value

fn into_box(self) -> BoxTransformer<T, R>

where Self: 'static,

Converts to BoxTransformer

fn into_rc(self) -> RcTransformer<T, R>

where Self: 'static,

Converts to RcTransformer

fn into_arc(self) -> ArcTransformer<T, R>

Converts to ArcTransformer

fn into_fn(self) -> impl Fn(T) -> R

Converts transformer to a closure

fn into_once(self) -> BoxTransformerOnce<T, R>

where Self: 'static,

Converts to BoxTransformerOnce.

fn to_box(&self) -> BoxTransformer<T, R>

where Self: 'static,

Converts to BoxTransformer without consuming self

fn to_rc(&self) -> RcTransformer<T, R>

where Self: 'static,

Converts to RcTransformer without consuming self

fn to_arc(&self) -> ArcTransformer<T, R>

Converts to ArcTransformer without consuming self

fn to_fn(&self) -> impl Fn(T) -> R

Converts transformer to a closure without consuming self

fn to_once(&self) -> BoxTransformerOnce<T, R>

where Self: 'static,

Converts to BoxTransformerOnce without consuming self