mutator_demo/
mutator_demo.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025 - 2026.
4 *    Haixing Hu, Qubit Co. Ltd.
5 *
6 *    All rights reserved.
7 *
8 ******************************************************************************/
9
10//! Mutator Type Demo
11//!
12//! This example demonstrates the three implementations of Mutator (BoxMutator, ArcMutator, RcMutator)
13//! and their various usage patterns.
14//!
15//! Mutator is used to modify values, unlike the non-mutating Consumer.
16
17use qubit_function::{
18    ArcMutator,
19    BoxMutator,
20    FnMutatorOps,
21    Mutator,
22    RcMutator,
23};
24use std::thread;
25
26fn main() {
27    println!("=== Mutator Demo ===\n");
28
29    // ========================================================================
30    // Example 1: BoxMutator Basic Usage
31    // ========================================================================
32    println!("Example 1: BoxMutator Basic Usage");
33    println!("{}", "-".repeat(50));
34
35    let mutator = BoxMutator::new(|x: &mut i32| {
36        *x *= 2;
37    });
38    let mut value = 5;
39    println!("Initial value: {}", value);
40    mutator.apply(&mut value);
41    println!("After BoxMutator execution: {}\n", value);
42
43    // ========================================================================
44    // Example 2: BoxMutator Method Chaining
45    // ========================================================================
46    println!("Example 2: BoxMutator Method Chaining");
47    println!("{}", "-".repeat(50));
48
49    let chained = BoxMutator::new(|x: &mut i32| {
50        *x *= 2; // multiply by 2
51    })
52    .and_then(|x: &mut i32| {
53        *x += 10; // add 10
54    })
55    .and_then(|x: &mut i32| {
56        *x = *x * *x; // square
57    });
58
59    let mut value = 5;
60    println!("Initial value: {}", value);
61    chained.apply(&mut value);
62    println!("Result: {} (5 * 2 + 10 = 20, 20 * 20 = 400)\n", value);
63
64    // ========================================================================
65    // Example 3: Closure Extension Methods
66    // ========================================================================
67    println!("Example 3: Direct Use of Closure Extension Methods");
68    println!("{}", "-".repeat(50));
69
70    let closure_chain = (|x: &mut i32| *x *= 2).and_then(|x: &mut i32| *x += 10);
71
72    let mut value = 5;
73    println!("Initial value: {}", value);
74    closure_chain.apply(&mut value);
75    println!("Result: {} (5 * 2 + 10 = 20)\n", value);
76
77    // ========================================================================
78    // Example 4: BoxMutator Factory Methods
79    // ========================================================================
80    println!("Example 4: BoxMutator Factory Methods");
81    println!("{}", "-".repeat(50));
82
83    // noop
84    let noop = BoxMutator::<i32>::noop();
85    let mut value = 42;
86    println!("Before noop: {}", value);
87    noop.apply(&mut value);
88    println!("After noop: {} (unchanged)\n", value);
89
90    // ========================================================================
91    // Example 5: Conditional Mutator
92    // ========================================================================
93    println!("Example 5: Conditional Mutator");
94    println!("{}", "-".repeat(50));
95
96    // when (conditional execution)
97    let increment_if_positive = BoxMutator::new(|x: &mut i32| *x += 1).when(|x: &i32| *x > 0);
98
99    let mut positive = 5;
100    let mut negative = -5;
101    println!(
102        "Before when - positive: {}, negative: {}",
103        positive, negative
104    );
105    increment_if_positive.apply(&mut positive);
106    increment_if_positive.apply(&mut negative);
107    println!(
108        "After when - positive: {}, negative: {}\n",
109        positive, negative
110    );
111
112    // when().or_else() (conditional branching)
113    let adjust = BoxMutator::new(|x: &mut i32| *x *= 2)
114        .when(|x: &i32| *x > 0)
115        .or_else(|x: &mut i32| *x = -*x);
116
117    let mut positive = 10;
118    let mut negative = -10;
119    println!(
120        "Before when().or_else() - positive: {}, negative: {}",
121        positive, negative
122    );
123    adjust.apply(&mut positive);
124    adjust.apply(&mut negative);
125    println!(
126        "After when().or_else() - positive: {}, negative: {}\n",
127        positive, negative
128    );
129
130    // ========================================================================
131    // Example 6: ArcMutator - Multi-threaded Sharing
132    // ========================================================================
133    println!("Example 6: ArcMutator - Multi-threaded Sharing");
134    println!("{}", "-".repeat(50));
135
136    let shared = ArcMutator::new(|x: &mut i32| *x *= 2);
137
138    // Clone for another thread
139    let shared_clone = shared.clone();
140    let handle = thread::spawn(move || {
141        let mut value = 5;
142        let mutator = shared_clone;
143        mutator.apply(&mut value);
144        println!("In thread: 5 * 2 = {}", value);
145        value
146    });
147
148    // Use in main thread
149    let mut value = 3;
150    let mutator = shared;
151    mutator.apply(&mut value);
152    println!("Main thread: 3 * 2 = {}", value);
153
154    let thread_result = handle.join().unwrap();
155    println!("Thread result: {}\n", thread_result);
156
157    // ========================================================================
158    // Example 7: ArcMutator Composition (without consuming original mutator)
159    // ========================================================================
160    println!("Example 7: ArcMutator Composition (borrowing &self)");
161    println!("{}", "-".repeat(50));
162
163    let double = ArcMutator::new(|x: &mut i32| *x *= 2);
164    let add_ten = ArcMutator::new(|x: &mut i32| *x += 10);
165
166    // Composition doesn't consume the original mutator
167    let pipeline1 = double.and_then(add_ten.clone());
168    let pipeline2 = add_ten.and_then(double.clone());
169
170    let mut value1 = 5;
171    let p1 = pipeline1;
172    p1.apply(&mut value1);
173    println!("pipeline1 (double then add): 5 -> {}", value1);
174
175    let mut value2 = 5;
176    let p2 = pipeline2;
177    p2.apply(&mut value2);
178    println!("pipeline2 (add then double): 5 -> {}", value2);
179
180    // double and add_ten are still available
181    let mut value3 = 10;
182    let d = double;
183    d.apply(&mut value3);
184    println!("Original double still available: 10 -> {}\n", value3);
185
186    // ========================================================================
187    // Example 8: RcMutator - Single-threaded Sharing
188    // ========================================================================
189    println!("Example 8: RcMutator - Single-threaded Sharing");
190    println!("{}", "-".repeat(50));
191
192    let rc_mutator = RcMutator::new(|x: &mut i32| *x *= 2);
193
194    // Clone multiple copies
195    let clone1 = rc_mutator.clone();
196    let clone2 = rc_mutator.clone();
197
198    let mut value1 = 5;
199    let c1 = clone1;
200    c1.apply(&mut value1);
201    println!("clone1: 5 -> {}", value1);
202
203    let mut value2 = 3;
204    let c2 = clone2;
205    c2.apply(&mut value2);
206    println!("clone2: 3 -> {}", value2);
207
208    let mut value3 = 7;
209    let c3 = rc_mutator;
210    c3.apply(&mut value3);
211    println!("Original: 7 -> {}\n", value3);
212
213    // ========================================================================
214    // Example 9: RcMutator Composition (borrowing &self)
215    // ========================================================================
216    println!("Example 9: RcMutator Composition (borrowing &self)");
217    println!("{}", "-".repeat(50));
218
219    let double = RcMutator::new(|x: &mut i32| *x *= 2);
220    let add_ten = RcMutator::new(|x: &mut i32| *x += 10);
221
222    let pipeline1 = double.and_then(add_ten.clone());
223    let pipeline2 = add_ten.and_then(double.clone());
224
225    let mut value1 = 5;
226    let p1 = pipeline1;
227    p1.apply(&mut value1);
228    println!("pipeline1 (double then add): 5 -> {}", value1);
229
230    let mut value2 = 5;
231    let p2 = pipeline2;
232    p2.apply(&mut value2);
233    println!("pipeline2 (add then double): 5 -> {}\n", value2);
234
235    // ========================================================================
236    // Example 10: Unified Mutator trait
237    // ========================================================================
238    println!("Example 10: Unified Mutator trait");
239    println!("{}", "-".repeat(50));
240
241    fn apply_to_all<M: Mutator<i32>>(mutator: &mut M, values: &mut [i32]) {
242        for value in values.iter_mut() {
243            mutator.apply(value);
244        }
245    }
246
247    let mut values1 = vec![1, 2, 3, 4, 5];
248    let mut box_mut = BoxMutator::new(|x: &mut i32| *x *= 2);
249    println!("Using BoxMutator: {:?}", values1);
250    apply_to_all(&mut box_mut, &mut values1);
251    println!("Result: {:?}", values1);
252
253    let mut values2 = vec![1, 2, 3, 4, 5];
254    let mut arc_mut = ArcMutator::new(|x: &mut i32| *x *= 2);
255    println!("Using ArcMutator: {:?}", values2);
256    apply_to_all(&mut arc_mut, &mut values2);
257    println!("Result: {:?}", values2);
258
259    let mut values3 = vec![1, 2, 3, 4, 5];
260    let mut rc_mut = RcMutator::new(|x: &mut i32| *x *= 2);
261    println!("Using RcMutator: {:?}", values3);
262    apply_to_all(&mut rc_mut, &mut values3);
263    println!("Result: {:?}", values3);
264
265    let mut values4 = vec![1, 2, 3, 4, 5];
266    let mut closure = |x: &mut i32| *x *= 2;
267    println!("Using closure: {:?}", values4);
268    apply_to_all(&mut closure, &mut values4);
269    println!("Result: {:?}\n", values4);
270
271    // ========================================================================
272    // Example 11: Complex Data Processing Pipeline
273    // ========================================================================
274    println!("Example 11: Complex Data Processing Pipeline");
275    println!("{}", "-".repeat(50));
276
277    let pipeline = BoxMutator::new(|x: &mut i32| {
278        // Validation: clamp to 0-100
279        *x = (*x).clamp(0, 100);
280    })
281    .and_then(|x: &mut i32| {
282        // Normalization: scale to 0-10
283        *x /= 10;
284    })
285    .and_then(|x: &mut i32| {
286        // Transformation: square
287        *x = *x * *x;
288    });
289
290    let mut value1 = -50;
291    pipeline.apply(&mut value1);
292    println!("-50 -> {}", value1);
293
294    let mut value2 = 200;
295    pipeline.apply(&mut value2);
296    println!("200 -> {}", value2);
297
298    let mut value3 = 30;
299    pipeline.apply(&mut value3);
300    println!("30 -> {}\n", value3);
301
302    // ========================================================================
303    // Example 12: String Processing
304    // ========================================================================
305    println!("Example 12: String Processing");
306    println!("{}", "-".repeat(50));
307
308    let string_processor = BoxMutator::new(|s: &mut String| s.retain(|c| !c.is_whitespace()))
309        .and_then(|s: &mut String| *s = s.to_lowercase())
310        .and_then(|s: &mut String| s.push_str("!!!"));
311
312    let mut text = String::from("Hello World");
313    println!("Original: {}", text);
314    string_processor.apply(&mut text);
315    println!("After processing: {}\n", text);
316
317    // ========================================================================
318    // Example 13: Type Conversion
319    // ========================================================================
320    println!("Example 13: Type Conversion");
321    println!("{}", "-".repeat(50));
322
323    // Closure -> BoxMutator
324    let closure = |x: &mut i32| *x *= 2;
325    let box_mut = closure.into_box();
326    let mut value = 5;
327    box_mut.apply(&mut value);
328    println!("Closure -> BoxMutator: 5 -> {}", value);
329
330    // Closure -> RcMutator
331    let closure = |x: &mut i32| *x *= 2;
332    let rc_mut = closure.into_rc();
333    let mut value = 5;
334    rc_mut.apply(&mut value);
335    println!("Closure -> RcMutator: 5 -> {}", value);
336
337    // Closure -> ArcMutator
338    let closure = |x: &mut i32| *x *= 2;
339    let arc_mut = closure.into_arc();
340    let mut value = 5;
341    arc_mut.apply(&mut value);
342    println!("Closure -> ArcMutator: 5 -> {}", value);
343
344    // BoxMutator -> RcMutator
345    let box_mut = BoxMutator::new(|x: &mut i32| *x *= 2);
346    let rc_mut = box_mut.into_rc();
347    let mut value = 5;
348    rc_mut.apply(&mut value);
349    println!("BoxMutator -> RcMutator: 5 -> {}", value);
350
351    // RcMutator -> BoxMutator
352    let rc_mut = RcMutator::new(|x: &mut i32| *x *= 2);
353    let box_mut = rc_mut.into_box();
354    let mut value = 5;
355    box_mut.apply(&mut value);
356    println!("RcMutator -> BoxMutator: 5 -> {}\n", value);
357
358    // ========================================================================
359    // Example 14: Custom Types
360    // ========================================================================
361    println!("Example 14: Custom Types");
362    println!("{}", "-".repeat(50));
363
364    #[derive(Debug, Clone)]
365    struct Point {
366        x: i32,
367        y: i32,
368    }
369
370    let processor = BoxMutator::new(|p: &mut Point| p.x *= 2)
371        .and_then(|p: &mut Point| p.y *= 2)
372        .and_then(|p: &mut Point| p.x += p.y);
373
374    let mut point = Point { x: 3, y: 4 };
375    println!("Original point: {:?}", point);
376    processor.apply(&mut point);
377    println!("After processing: {:?}\n", point);
378
379    println!("=== All Examples Completed ===");
380}
mutator_demo/mutator_demo.rs

mutator_demo/
mutator_demo.rs
