always_bi_predicate_demo/
always_bi_predicate_demo.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025.
4 *    3-Prism Co. Ltd.
5 *
6 *    All rights reserved.
7 *
8 ******************************************************************************/
9use prism3_function::bi_predicate::{ArcBiPredicate, BiPredicate, BoxBiPredicate, RcBiPredicate};
10
11fn main() {
12    println!("=== BoxBiPredicate always_true/always_false Demo ===\n");
13
14    // BoxBiPredicate::always_true
15    let always_true: BoxBiPredicate<i32, i32> = BoxBiPredicate::always_true();
16    println!("BoxBiPredicate::always_true():");
17    println!("  test(&42, &10): {}", always_true.test(&42, &10));
18    println!("  test(&-1, &5): {}", always_true.test(&-1, &5));
19    println!("  test(&0, &0): {}", always_true.test(&0, &0));
20    println!("  name: {:?}", always_true.name());
21
22    // BoxBiPredicate::always_false
23    let always_false: BoxBiPredicate<i32, i32> = BoxBiPredicate::always_false();
24    println!("\nBoxBiPredicate::always_false():");
25    println!("  test(&42, &10): {}", always_false.test(&42, &10));
26    println!("  test(&-1, &5): {}", always_false.test(&-1, &5));
27    println!("  test(&0, &0): {}", always_false.test(&0, &0));
28    println!("  name: {:?}", always_false.name());
29
30    println!("\n=== RcBiPredicate always_true/always_false Demo ===\n");
31
32    // RcBiPredicate::always_true
33    let rc_always_true: RcBiPredicate<String, i32> = RcBiPredicate::always_true();
34    println!("RcBiPredicate::always_true():");
35    println!(
36        "  test(&\"hello\", &5): {}",
37        rc_always_true.test(&"hello".to_string(), &5)
38    );
39    println!(
40        "  test(&\"world\", &-3): {}",
41        rc_always_true.test(&"world".to_string(), &-3)
42    );
43    println!("  name: {:?}", rc_always_true.name());
44
45    // RcBiPredicate::always_false
46    let rc_always_false: RcBiPredicate<String, i32> = RcBiPredicate::always_false();
47    println!("\nRcBiPredicate::always_false():");
48    println!(
49        "  test(&\"hello\", &5): {}",
50        rc_always_false.test(&"hello".to_string(), &5)
51    );
52    println!(
53        "  test(&\"world\", &-3): {}",
54        rc_always_false.test(&"world".to_string(), &-3)
55    );
56    println!("  name: {:?}", rc_always_false.name());
57
58    // Can be cloned and reused
59    let rc_clone = rc_always_true.clone();
60    println!("\nAfter cloning, still usable:");
61    println!(
62        "  Original: test(&\"test\", &1): {}",
63        rc_always_true.test(&"test".to_string(), &1)
64    );
65    println!(
66        "  Clone: test(&\"test\", &2): {}",
67        rc_clone.test(&"test".to_string(), &2)
68    );
69
70    println!("\n=== ArcBiPredicate always_true/always_false Demo ===\n");
71
72    // ArcBiPredicate::always_true
73    let arc_always_true: ArcBiPredicate<i32, i32> = ArcBiPredicate::always_true();
74    println!("ArcBiPredicate::always_true():");
75    println!("  test(&100, &50): {}", arc_always_true.test(&100, &50));
76    println!("  test(&-100, &25): {}", arc_always_true.test(&-100, &25));
77    println!("  name: {:?}", arc_always_true.name());
78
79    // ArcBiPredicate::always_false
80    let arc_always_false: ArcBiPredicate<i32, i32> = ArcBiPredicate::always_false();
81    println!("\nArcBiPredicate::always_false():");
82    println!("  test(&100, &50): {}", arc_always_false.test(&100, &50));
83    println!("  test(&-100, &25): {}", arc_always_false.test(&-100, &25));
84    println!("  name: {:?}", arc_always_false.name());
85
86    println!("\n=== Combining with other bi-predicates ===\n");
87
88    // Combining with always_true (AND)
89    let sum_positive = BoxBiPredicate::new(|x: &i32, y: &i32| x + y > 0);
90    let combined_and_true = sum_positive.and(BoxBiPredicate::always_true());
91    println!("sum_positive AND always_true:");
92    println!(
93        "  test(&5, &3): {} (equivalent to sum_positive)",
94        combined_and_true.test(&5, &3)
95    );
96    println!(
97        "  test(&-3, &-5): {} (equivalent to sum_positive)",
98        combined_and_true.test(&-3, &-5)
99    );
100
101    // Combining with always_false (AND)
102    let sum_positive = BoxBiPredicate::new(|x: &i32, y: &i32| x + y > 0);
103    let combined_and_false = sum_positive.and(BoxBiPredicate::always_false());
104    println!("\nsum_positive AND always_false:");
105    println!(
106        "  test(&5, &3): {} (always false)",
107        combined_and_false.test(&5, &3)
108    );
109    println!(
110        "  test(&-3, &-5): {} (always false)",
111        combined_and_false.test(&-3, &-5)
112    );
113
114    // Combining with always_true (OR)
115    let sum_positive = BoxBiPredicate::new(|x: &i32, y: &i32| x + y > 0);
116    let combined_or_true = sum_positive.or(BoxBiPredicate::always_true());
117    println!("\nsum_positive OR always_true:");
118    println!(
119        "  test(&5, &3): {} (always true)",
120        combined_or_true.test(&5, &3)
121    );
122    println!(
123        "  test(&-3, &-5): {} (always true)",
124        combined_or_true.test(&-3, &-5)
125    );
126
127    // Combining with always_false (OR)
128    let sum_positive = BoxBiPredicate::new(|x: &i32, y: &i32| x + y > 0);
129    let combined_or_false = sum_positive.or(BoxBiPredicate::always_false());
130    println!("\nsum_positive OR always_false:");
131    println!(
132        "  test(&5, &3): {} (equivalent to sum_positive)",
133        combined_or_false.test(&5, &3)
134    );
135    println!(
136        "  test(&-3, &-5): {} (equivalent to sum_positive)",
137        combined_or_false.test(&-3, &-5)
138    );
139
140    println!("\n=== Practical scenarios: Default pass/reject filters ===\n");
141
142    // Scenario 1: Default pass-all filter
143    let pairs = vec![(1, 2), (3, 4), (5, 6)];
144    let pass_all = BoxBiPredicate::<i32, i32>::always_true();
145    let closure = pass_all.into_fn();
146    let filtered: Vec<_> = pairs.iter().filter(|(x, y)| closure(x, y)).collect();
147    println!("Default pass all elements: {:?} -> {:?}", pairs, filtered);
148
149    // Scenario 2: Default reject-all filter
150    let pairs = vec![(1, 2), (3, 4), (5, 6)];
151    let reject_all = BoxBiPredicate::<i32, i32>::always_false();
152    let closure = reject_all.into_fn();
153    let filtered: Vec<_> = pairs.iter().filter(|(x, y)| closure(x, y)).collect();
154    println!("Default reject all elements: {:?} -> {:?}", pairs, filtered);
155
156    // Scenario 3: Configurable filter
157    fn configurable_filter(enable_filter: bool) -> BoxBiPredicate<i32, i32> {
158        if enable_filter {
159            BoxBiPredicate::new(|x: &i32, y: &i32| x + y > 5)
160        } else {
161            BoxBiPredicate::always_true()
162        }
163    }
164
165    let pairs = vec![(1, 2), (3, 4), (5, 6)];
166
167    let filter_enabled = configurable_filter(true);
168    let closure = filter_enabled.into_fn();
169    let filtered: Vec<_> = pairs.iter().filter(|(x, y)| closure(x, y)).collect();
170    println!("\nFilter enabled: {:?} -> {:?}", pairs, filtered);
171
172    let filter_disabled = configurable_filter(false);
173    let closure = filter_disabled.into_fn();
174    let filtered: Vec<_> = pairs.iter().filter(|(x, y)| closure(x, y)).collect();
175    println!("Filter disabled: {:?} -> {:?}", pairs, filtered);
176}
always_bi_predicate_demo/always_bi_predicate_demo.rs

always_bi_predicate_demo/
always_bi_predicate_demo.rs
