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
49        .when(|x: &i32, y: &i32| *x > 0 && *y > 0)
50        .or_else(multiply);
51    println!("   conditional(5, 3) = {} (add)", conditional.apply(5, 3));
52
53    println!("\n6. Conditional transformation (negative numbers):");
54    let add2 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
55    let multiply2 = BoxBiTransformerOnce::new(|x: i32, y: i32| x * y);
56    let conditional2 = add2
57        .when(|x: &i32, y: &i32| *x > 0 && *y > 0)
58        .or_else(multiply2);
59    println!(
60        "   conditional(-5, 3) = {} (multiply)",
61        conditional2.apply(-5, 3)
62    );
63
64    // Example 7: Conditional with closure in or_else
65    println!("\n7. Conditional with closure in or_else:");
66    let add3 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
67    let conditional3 = add3
68        .when(|x: &i32, y: &i32| *x > 0 && *y > 0)
69        .or_else(|x: i32, y: i32| x * y);
70    println!("   conditional(4, 6) = {}", conditional3.apply(4, 6));
71
72    // Example 8: Merging vectors
73    println!("\n8. Merging vectors:");
74    let merge = BoxBiTransformerOnce::new(|mut x: Vec<i32>, y: Vec<i32>| {
75        x.extend(y);
76        x
77    });
78    let v1 = vec![1, 2, 3];
79    let v2 = vec![4, 5, 6];
80    let result = merge.apply(v1, v2);
81    println!("   merge([1, 2, 3], [4, 5, 6]) = {:?}", result);
82
83    // Example 9: Complex transformation with calculation
84    println!("\n9. Complex transformation with calculation:");
85    let calculate = BoxBiTransformerOnce::new(|x: i32, y: i32| {
86        let sum = x + y;
87        let product = x * y;
88        (sum, product)
89    });
90    let (sum, product) = calculate.apply(5, 3);
91    println!("   calculate(5, 3) = (sum: {}, product: {})", sum, product);
92
93    // Example 10: String manipulation
94    println!("\n10. String manipulation:");
95    let process = BoxBiTransformerOnce::new(|x: String, y: String| {
96        format!("{} {} {}", x.to_uppercase(), "and", y.to_lowercase())
97    });
98    println!(
99        "   process('Hello', 'WORLD') = {}",
100        process.apply("Hello".to_string(), "WORLD".to_string())
101    );
102
103    // Example 11: Converting to function
104    println!("\n11. Converting to function:");
105    let add4 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
106    let f = add4.into_fn();
107    println!("   f(10, 20) = {}", f(10, 20));
108
109    // Example 12: Converting to box (zero-cost)
110    println!("\n12. Converting to box (zero-cost):");
111    let add5 = BoxBiTransformerOnce::new(|x: i32, y: i32| x + y);
112    let boxed = add5.into_box();
113    println!("   boxed(15, 25) = {}", boxed.apply(15, 25));
114
115    println!("\n=== All examples completed successfully! ===");
116}
bi_transformer_once_demo/bi_transformer_once_demo.rs

bi_transformer_once_demo/
bi_transformer_once_demo.rs
