bi_transformer_once_demo/
bi_transformer_once_demo.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025 - 2026 Haixing Hu.
4 *
5 *    SPDX-License-Identifier: Apache-2.0
6 *
7 *    Licensed under the Apache License, Version 2.0.
8 *
9 ******************************************************************************/
10//! BiTransformerOnce usage examples
11
12use qubit_function::{
13    BiTransformerOnce,
14    BoxBiTransformerOnce,
15};
16
17fn main() {
18    println!("=== BiTransformerOnce Examples ===\n");
19
20    // Example 1: Basic usage with closure
21    println!("1. Basic usage with closure:");
22    let add = |x: i32, y: i32| x + y;
23    let result = add.apply(20, 22);
24    println!("   20 + 22 = {}", result);
25
26    // Example 2: BoxBiTransformerOnce with new
27    println!("\n2. BoxBiTransformerOnce with new:");
28    let multiply = BoxBiTransformerOnce::new(|x: i32, y: i32| x * y);
29    println!("   6 * 7 = {}", multiply.apply(6, 7));
30
31    // Example 3: Constant transformer
32    println!("\n3. Constant transformer:");
33    let constant = BoxBiTransformerOnce::constant("hello");
34    println!("   constant(123, 456) = {}", constant.apply(123, 456));
35
36    // Example 4: Consuming owned values
37    println!("\n4. Consuming owned values:");
38    let concat = BoxBiTransformerOnce::new(|x: String, y: String| format!("{} {}", x, y));
39    let s1 = String::from("hello");
40    let s2 = String::from("world");
41    let result = concat.apply(s1, s2);
42    println!("   concat('hello', 'world') = {}", result);
43
44    // Example 5: Conditional transformation with when/or_else
45    println!("\n5. Conditional transformation (positive numbers):");
46    let add = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
47    let multiply = BoxBiTransformerOnce::new(|x: i32, y: i32| x * y);
48    let conditional = add.when(|x: &i32, y: &i32| *x > 0 && *y > 0).or_else(multiply);
49    println!("   conditional(5, 3) = {} (add)", conditional.apply(5, 3));
50
51    println!("\n6. Conditional transformation (negative numbers):");
52    let add2 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
53    let multiply2 = BoxBiTransformerOnce::new(|x: i32, y: i32| x * y);
54    let conditional2 = add2.when(|x: &i32, y: &i32| *x > 0 && *y > 0).or_else(multiply2);
55    println!("   conditional(-5, 3) = {} (multiply)", conditional2.apply(-5, 3));
56
57    // Example 7: Conditional with closure in or_else
58    println!("\n7. Conditional with closure in or_else:");
59    let add3 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
60    let conditional3 = add3
61        .when(|x: &i32, y: &i32| *x > 0 && *y > 0)
62        .or_else(|x: i32, y: i32| x * y);
63    println!("   conditional(4, 6) = {}", conditional3.apply(4, 6));
64
65    // Example 8: Merging vectors
66    println!("\n8. Merging vectors:");
67    let merge = BoxBiTransformerOnce::new(|mut x: Vec<i32>, y: Vec<i32>| {
68        x.extend(y);
69        x
70    });
71    let v1 = vec![1, 2, 3];
72    let v2 = vec![4, 5, 6];
73    let result = merge.apply(v1, v2);
74    println!("   merge([1, 2, 3], [4, 5, 6]) = {:?}", result);
75
76    // Example 9: Complex transformation with calculation
77    println!("\n9. Complex transformation with calculation:");
78    let calculate = BoxBiTransformerOnce::new(|x: i32, y: i32| {
79        let sum = x + y;
80        let product = x * y;
81        (sum, product)
82    });
83    let (sum, product) = calculate.apply(5, 3);
84    println!("   calculate(5, 3) = (sum: {}, product: {})", sum, product);
85
86    // Example 10: String manipulation
87    println!("\n10. String manipulation:");
88    let process = BoxBiTransformerOnce::new(|x: String, y: String| {
89        format!("{} {} {}", x.to_uppercase(), "and", y.to_lowercase())
90    });
91    println!(
92        "   process('Hello', 'WORLD') = {}",
93        process.apply("Hello".to_string(), "WORLD".to_string())
94    );
95
96    // Example 11: Converting to function
97    println!("\n11. Converting to function:");
98    let add4 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
99    let f = add4.into_fn();
100    println!("   f(10, 20) = {}", f(10, 20));
101
102    // Example 12: Converting to box (zero-cost)
103    println!("\n12. Converting to box (zero-cost):");
104    let add5 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
105    let boxed = add5.into_box();
106    println!("   boxed(15, 25) = {}", boxed.apply(15, 25));
107
108    println!("\n=== All examples completed successfully! ===");
109}
bi_transformer_once_demo/bi_transformer_once_demo.rs

bi_transformer_once_demo/
bi_transformer_once_demo.rs
