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solverforge_solver/heuristic/selector/
list_reverse.rs

1//! Public static adapter for the canonical list-reverse cursor.
2
3use std::fmt::Debug;
4use std::marker::PhantomData;
5
6use solverforge_core::domain::PlanningSolution;
7use solverforge_scoring::Director;
8
9use crate::heuristic::r#move::ListReverseMove;
10use crate::heuristic::selector::list_kernel::{
11    NativeReverseEmitter, ReverseCursor, STATIC_REVERSE_ENTITY_SALT,
12};
13
14use super::entity::EntitySelector;
15use super::move_selector::{
16    CandidateId, MoveCandidateRef, MoveCursor, MoveSelector, MoveStreamContext,
17};
18
19pub struct ListReverseMoveSelector<S, V, ES> {
20    entity_selector: ES,
21    list_len: fn(&S, usize) -> usize,
22    list_get: fn(&S, usize, usize) -> Option<V>,
23    list_reverse: fn(&mut S, usize, usize, usize),
24    variable_name: &'static str,
25    descriptor_index: usize,
26    _phantom: PhantomData<(fn() -> S, fn() -> V)>,
27}
28
29/// Public cursor facade over the crate-private generic kernel.
30pub struct ListReverseMoveCursor<S, V>
31where
32    S: PlanningSolution,
33    V: Clone + Send + Sync + Debug + 'static,
34{
35    inner: ReverseCursor<S, NativeReverseEmitter<S, V>>,
36}
37
38impl<S, V> ListReverseMoveCursor<S, V>
39where
40    S: PlanningSolution,
41    V: Clone + Send + Sync + Debug + 'static,
42{
43    fn new(inner: ReverseCursor<S, NativeReverseEmitter<S, V>>) -> Self {
44        Self { inner }
45    }
46}
47
48impl<S, V> MoveCursor<S, ListReverseMove<S, V>> for ListReverseMoveCursor<S, V>
49where
50    S: PlanningSolution,
51    V: Clone + Send + Sync + Debug + 'static,
52{
53    fn next_candidate(&mut self, solution: &S) -> Option<CandidateId> {
54        self.inner.next_candidate(solution)
55    }
56
57    fn candidate(&self, id: CandidateId) -> Option<MoveCandidateRef<'_, S, ListReverseMove<S, V>>> {
58        self.inner.candidate(id)
59    }
60
61    fn take_candidate(&mut self, id: CandidateId) -> ListReverseMove<S, V> {
62        self.inner.take_candidate(id)
63    }
64
65    fn next_owned_candidate(&mut self, solution: &S) -> Option<ListReverseMove<S, V>> {
66        self.inner.next_owned_candidate(solution)
67    }
68
69    fn next_owned_candidate_matching(
70        &mut self,
71        solution: &S,
72        predicate: for<'a> fn(MoveCandidateRef<'a, S, ListReverseMove<S, V>>) -> bool,
73    ) -> Option<ListReverseMove<S, V>> {
74        self.inner
75            .next_owned_candidate_matching(solution, predicate)
76    }
77
78    fn release_candidate(&mut self, id: CandidateId) -> bool {
79        self.inner.release_candidate(id)
80    }
81}
82
83impl<S, V: Debug, ES: Debug> Debug for ListReverseMoveSelector<S, V, ES> {
84    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
85        f.debug_struct("ListReverseMoveSelector")
86            .field("entity_selector", &self.entity_selector)
87            .field("variable_name", &self.variable_name)
88            .field("descriptor_index", &self.descriptor_index)
89            .finish()
90    }
91}
92
93impl<S, V, ES> ListReverseMoveSelector<S, V, ES> {
94    pub fn new(
95        entity_selector: ES,
96        list_len: fn(&S, usize) -> usize,
97        list_get: fn(&S, usize, usize) -> Option<V>,
98        list_reverse: fn(&mut S, usize, usize, usize),
99        variable_name: &'static str,
100        descriptor_index: usize,
101    ) -> Self {
102        Self {
103            entity_selector,
104            list_len,
105            list_get,
106            list_reverse,
107            variable_name,
108            descriptor_index,
109            _phantom: PhantomData,
110        }
111    }
112}
113
114impl<S, V, ES> MoveSelector<S, ListReverseMove<S, V>> for ListReverseMoveSelector<S, V, ES>
115where
116    S: PlanningSolution,
117    V: Clone + Send + Sync + Debug + 'static,
118    ES: EntitySelector<S>,
119{
120    type Cursor<'a>
121        = ListReverseMoveCursor<S, V>
122    where
123        Self: 'a;
124
125    fn open_cursor<'a, D: Director<S>>(&'a self, score_director: &D) -> Self::Cursor<'a> {
126        self.open_cursor_with_context(score_director, MoveStreamContext::default())
127    }
128
129    fn open_cursor_with_context<'a, D: Director<S>>(
130        &'a self,
131        score_director: &D,
132        context: MoveStreamContext,
133    ) -> Self::Cursor<'a> {
134        let canonical_entities = self
135            .entity_selector
136            .iter(score_director)
137            .map(|reference| reference.entity_index)
138            .collect::<Vec<_>>();
139        let salt = STATIC_REVERSE_ENTITY_SALT ^ self.descriptor_index as u64;
140        let entities = (0..canonical_entities.len())
141            .map(|offset| {
142                canonical_entities[context.selection_index(offset, canonical_entities.len(), salt)]
143            })
144            .collect::<Vec<_>>();
145        let solution = score_director.working_solution();
146        let route_lens = entities
147            .iter()
148            .map(|&entity| (self.list_len)(solution, entity))
149            .collect();
150        ListReverseMoveCursor::new(ReverseCursor::new(
151            NativeReverseEmitter::new(
152                self.list_len,
153                self.list_get,
154                self.list_reverse,
155                self.variable_name,
156                self.descriptor_index,
157            ),
158            entities,
159            route_lens,
160            context,
161            self.descriptor_index,
162        ))
163    }
164
165    fn size<D: Director<S>>(&self, score_director: &D) -> usize {
166        let solution = score_director.working_solution();
167        self.entity_selector
168            .iter(score_director)
169            .map(|reference| {
170                let len = (self.list_len)(solution, reference.entity_index);
171                if len >= 2 {
172                    len * (len - 1) / 2
173                } else {
174                    0
175                }
176            })
177            .sum()
178    }
179}