qubit_function/functions/stateful_mutating_function/rc_conditional_stateful_mutating_function.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// qubit-style: allow explicit-imports
11//! Defines the `RcConditionalStatefulMutatingFunction` public type.
12
13#![allow(unused_imports)]
14
15use super::*;
16
17// ============================================================================
18// RcConditionalStatefulMutatingFunction - Rc-based Conditional Stateful Mutating Function
19// ============================================================================
20
21/// RcConditionalStatefulMutatingFunction struct
22///
23/// A single-threaded conditional function that only executes when a
24/// predicate is satisfied. Uses `RcStatefulMutatingFunction` and `RcPredicate` for shared
25/// ownership within a single thread.
26///
27/// This type is typically created by calling `RcStatefulMutatingFunction::when()` and is
28/// designed to work with the `or_else()` method to create if-then-else logic.
29///
30/// # Features
31///
32/// - **Shared Ownership**: Cloneable via `Rc`, multiple owners allowed
33/// - **Single-Threaded**: Not thread-safe, cannot be sent across threads
34/// - **Conditional Execution**: Only transforms when predicate returns `true`
35/// - **No Lock Overhead**: More efficient than `ArcConditionalFunction`
36///
37/// # Examples
38///
39/// ```rust
40/// use qubit_function::{StatefulMutatingFunction, RcStatefulMutatingFunction};
41///
42/// let double = RcStatefulMutatingFunction::new(|x: &mut i32| {
43/// *x *= 2;
44/// *x
45/// });
46/// let identity = RcStatefulMutatingFunction::<i32, i32>::identity();
47/// let mut conditional = double.when(|x: &i32| *x > 0).or_else(identity);
48///
49/// let mut conditional_clone = conditional.clone();
50///
51/// let mut positive = 5;
52/// let mut negative = -5;
53/// assert_eq!(conditional.apply(&mut positive), 10);
54/// assert_eq!(conditional_clone.apply(&mut negative), -5);
55/// ```
56///
57pub struct RcConditionalStatefulMutatingFunction<T, R> {
58 pub(super) function: RcStatefulMutatingFunction<T, R>,
59 pub(super) predicate: RcPredicate<T>,
60}
61
62// Use macro to generate conditional function implementations
63impl_shared_conditional_function!(
64 RcConditionalStatefulMutatingFunction<T, R>,
65 RcStatefulMutatingFunction,
66 StatefulMutatingFunction,
67 'static
68);
69
70// Use macro to generate conditional function clone implementations
71impl_conditional_function_clone!(RcConditionalStatefulMutatingFunction<T, R>);
72
73// Use macro to generate conditional function debug and display implementations
74impl_conditional_function_debug_display!(RcConditionalStatefulMutatingFunction<T, R>);