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qubit_function/functions/stateful_mutating_function/
arc_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 `ArcConditionalStatefulMutatingFunction` public type.
12
13use super::{
14    ArcPredicate,
15    ArcStatefulMutatingFunction,
16    Predicate,
17    StatefulMutatingFunction,
18    impl_conditional_function_clone,
19    impl_conditional_function_debug_display,
20    impl_shared_conditional_function,
21};
22
23// ============================================================================
24// ArcConditionalStatefulMutatingFunction - Arc-based Conditional Stateful Mutating Function
25// ============================================================================
26
27/// ArcConditionalStatefulMutatingFunction struct
28///
29/// A thread-safe conditional function that only executes when a predicate is
30/// satisfied. Uses `ArcStatefulMutatingFunction` and `ArcPredicate` for shared ownership
31/// across threads.
32///
33/// This type is typically created by calling `ArcStatefulMutatingFunction::when()` and is
34/// designed to work with the `or_else()` method to create if-then-else logic.
35///
36/// # Features
37///
38/// - **Shared Ownership**: Cloneable via `Arc`, multiple owners allowed
39/// - **Thread-Safe**: Implements `Send + Sync`, safe for concurrent use
40/// - **Conditional Execution**: Only transforms when predicate returns `true`
41/// - **Chainable**: Can add `or_else` branch to create if-then-else logic
42///
43/// # Examples
44///
45/// ```rust
46/// use qubit_function::{StatefulMutatingFunction, ArcStatefulMutatingFunction};
47///
48/// let double = ArcStatefulMutatingFunction::new(|x: &mut i32| {
49///     *x *= 2;
50///     *x
51/// });
52/// let identity = ArcStatefulMutatingFunction::<i32, i32>::identity();
53/// let mut conditional = double.when(|x: &i32| *x > 0).or_else(identity);
54///
55/// let mut conditional_clone = conditional.clone();
56///
57/// let mut positive = 5;
58/// let mut negative = -5;
59/// assert_eq!(conditional.apply(&mut positive), 10);
60/// assert_eq!(conditional_clone.apply(&mut negative), -5);
61/// ```
62///
63pub struct ArcConditionalStatefulMutatingFunction<T, R> {
64    pub(super) function: ArcStatefulMutatingFunction<T, R>,
65    pub(super) predicate: ArcPredicate<T>,
66}
67
68// Use macro to generate conditional function implementations
69impl_shared_conditional_function!(
70    ArcConditionalStatefulMutatingFunction<T, R>,
71    ArcStatefulMutatingFunction,
72    StatefulMutatingFunction,
73    Send + Sync + 'static
74);
75
76// Use macro to generate conditional function clone implementations
77impl_conditional_function_clone!(ArcConditionalStatefulMutatingFunction<T, R>);
78
79// Use macro to generate conditional function debug and display implementations
80impl_conditional_function_debug_display!(ArcConditionalStatefulMutatingFunction<T, R>);