honeycomb_core/attributes/
manager.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
//! attribute super structure code
//!
//! this module contains all code used to implement a manager struct, used to handle generic
//! attributes embedded in a given combinatorial map.

// ------ IMPORTS

use stm::{StmError, Transaction};

use super::{AttributeBind, AttributeStorage, UnknownAttributeStorage};
use crate::prelude::{DartIdType, OrbitPolicy};
use std::{any::TypeId, collections::HashMap};

// ------ CONTENT

/// Main attribute storage structure.
///
/// This structure is used to store all generic attributes that the user may add to the
/// combinatorial map he's building.
///
/// # Implementation
///
/// The structure uses hashmaps in order to store each attribute's dedicated storage. Which storage
/// is used is determined by the associated type [`AttributeBind::StorageType`].
///
/// The key type used by the map is each attribute's [`TypeId`]. This implies that all attributes
/// must have a different (unique) type. For example, two decimal-valued attribute will need to be
/// wrapped in different dedicated structures.
///
/// Using the [`TypeId`] as the key value for collections yields a cleaner API, where the only
/// argument passed to access methods is the ID of the cell of which they want the attribute. The
/// actual attribute type is specified by passing a generic to the method. This bypasses any issues
/// linked to literal-typed keys, such as typos, naming conventions, portability, etc.
///
/// Generics passed in access methods also have a secondary usage. To store heterogeneous
/// collections, the internal hashmaps uses `Box<dyn UnknownAttributeStorage>` as their value type.
/// Some operations require us to downcast the stored object (implementing
/// `UnknownAttributeStorage`) to the correct collection type. This is achieved by using the
/// `downcast-rs` crate and the associated storage type [`AttributeBind::StorageType`]. What
/// follows is a simplified version of that code:
///
/// ```
/// # use std::any::TypeId;
/// # use std::collections::HashMap;
/// # use honeycomb_core::attributes::{AttributeBind, AttributeStorage, UnknownAttributeStorage};
/// pub struct Manager {
///     inner: HashMap<TypeId, Box<dyn UnknownAttributeStorage>>,
/// }
///
/// impl Manager {
///     pub fn add_storage<A: AttributeBind + 'static>(
///         &mut self,
///         size: usize,
///     ) {
///         let typeid = TypeId::of::<A>();
///         let new_storage = <A as AttributeBind>::StorageType::new(size);
///         self.inner.insert(typeid, Box::new(new_storage));
///     }
///
///     pub fn get_storage<A: AttributeBind>(&self) -> &<A as AttributeBind>::StorageType {
///         let probably_storage = &self.inner[&TypeId::of::<A>()];
///         // downcast is possible because:
///         // - StorageType: AttributeStorage<A>
///         // - AttributeStorage<A>: UnknownAttributeStorage
///         probably_storage
///             .downcast_ref::<<A as AttributeBind>::StorageType>()
///             .expect("E: could not downcast generic storage to specified attribute type")
///     }
/// }
/// ```
#[derive(Default)]
pub struct AttrStorageManager {
    /// Vertex attributes' storages.
    vertices: HashMap<TypeId, Box<dyn UnknownAttributeStorage>>,
    /// Edge attributes' storages.
    edges: HashMap<TypeId, Box<dyn UnknownAttributeStorage>>,
    /// Face attributes' storages.
    faces: HashMap<TypeId, Box<dyn UnknownAttributeStorage>>,
    /// Other storages.
    others: HashMap<TypeId, Box<dyn UnknownAttributeStorage>>, // Orbit::Custom
}

unsafe impl Send for AttrStorageManager {}
unsafe impl Sync for AttrStorageManager {}

/// **Manager-wide methods**
impl AttrStorageManager {
    /// Extend the size of all storages in the manager.
    ///
    /// # Arguments
    ///
    /// - `length: usize` -- Length by which storages should be extended.
    pub fn extend_storages(&mut self, length: usize) {
        for storage in self.vertices.values_mut() {
            storage.extend(length);
        }
        for storage in self.edges.values_mut() {
            storage.extend(length);
        }
        for storage in self.faces.values_mut() {
            storage.extend(length);
        }
        for storage in self.others.values_mut() {
            storage.extend(length);
        }
    }

    // merges

    /// Execute a merging operation on all attributes associated with a given orbit
    /// for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_attributes(
        &self,
        orbit_policy: &OrbitPolicy,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) {
        match orbit_policy {
            OrbitPolicy::Vertex => self.merge_vertex_attributes(id_out, id_in_lhs, id_in_rhs),
            OrbitPolicy::Edge => self.merge_edge_attributes(id_out, id_in_lhs, id_in_rhs),
            OrbitPolicy::Face => self.merge_face_attributes(id_out, id_in_lhs, id_in_rhs),
            OrbitPolicy::Custom(_) => {
                self.merge_other_attributes(orbit_policy, id_out, id_in_lhs, id_in_rhs);
            }
        }
    }

    /// Execute a merging operation on all attributes associated with vertices for specified cells.
    ///
    /// # Arguments
    ///
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_vertex_attributes(
        &self,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) {
        for storage in self.vertices.values() {
            storage.merge(id_out, id_in_lhs, id_in_rhs);
        }
    }

    /// Execute a merging operation on all attributes associated with edges for specified cells.
    ///
    /// # Arguments
    ///
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_edge_attributes(
        &self,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) {
        for storage in self.edges.values() {
            storage.merge(id_out, id_in_lhs, id_in_rhs);
        }
    }

    /// Execute a merging operation on all attributes associated with faces for specified cells.
    ///
    /// # Arguments
    ///
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_face_attributes(
        &self,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) {
        for storage in self.faces.values() {
            storage.merge(id_out, id_in_lhs, id_in_rhs);
        }
    }

    /// Execute a merging operation on all attributes associated with a given orbit
    /// for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_other_attributes(
        &self,
        _orbit_policy: &OrbitPolicy,
        _id_out: DartIdType,
        _id_in_lhs: DartIdType,
        _id_in_rhs: DartIdType,
    ) {
        todo!("custom orbit binding is a special case that will be treated later")
    }

    // splits

    /// Execute a splitting operation on all attributes associated with a given orbit
    /// for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_attributes(
        &self,
        orbit_policy: &OrbitPolicy,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) {
        match orbit_policy {
            OrbitPolicy::Vertex => self.split_vertex_attributes(id_out_lhs, id_out_rhs, id_in),
            OrbitPolicy::Edge => self.split_edge_attributes(id_out_lhs, id_out_rhs, id_in),
            OrbitPolicy::Face => self.split_face_attributes(id_out_lhs, id_out_rhs, id_in),
            OrbitPolicy::Custom(_) => {
                self.split_other_attributes(orbit_policy, id_out_lhs, id_out_rhs, id_in);
            }
        }
    }

    /// Execute a splitting operation on all attributes associated with vertices
    /// for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_vertex_attributes(
        &self,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) {
        for storage in self.vertices.values() {
            storage.split(id_out_lhs, id_out_rhs, id_in);
        }
    }

    /// Execute a splitting operation on all attributes associated with edges for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_edge_attributes(
        &self,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) {
        for storage in self.edges.values() {
            storage.split(id_out_lhs, id_out_rhs, id_in);
        }
    }

    /// Execute a splitting operation on all attributes associated with faces for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_face_attributes(
        &self,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) {
        for storage in self.faces.values() {
            storage.split(id_out_lhs, id_out_rhs, id_in);
        }
    }

    /// Execute a splitting operation on all attributes associated with a given orbit
    /// for specified cells.
    ///
    /// # Arguments
    ///
    /// - `orbit_policy: OrbitPolicy` -- Orbit associated with affected attributes.
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_other_attributes(
        &self,
        _orbit_policy: &OrbitPolicy,
        _id_out_lhs: DartIdType,
        _id_out_rhs: DartIdType,
        _id_in: DartIdType,
    ) {
        todo!("custom orbit binding is a special case that will be treated later")
    }
}

macro_rules! get_storage {
    ($slf: ident, $id: ident) => {
        let probably_storage = match A::BIND_POLICY {
            OrbitPolicy::Vertex => $slf.vertices.get(&TypeId::of::<A>()),
            OrbitPolicy::Edge => $slf.edges.get(&TypeId::of::<A>()),
            OrbitPolicy::Face => $slf.faces.get(&TypeId::of::<A>()),
            OrbitPolicy::Custom(_) => $slf.others.get(&TypeId::of::<A>()),
        };
        let $id = probably_storage
            .map(|m| m.downcast_ref::<<A as AttributeBind>::StorageType>())
            .flatten();
    };
}

macro_rules! get_storage_mut {
    ($slf: ident, $id: ident) => {
        let probably_storage = match A::BIND_POLICY {
            OrbitPolicy::Vertex => $slf.vertices.get_mut(&TypeId::of::<A>()),
            OrbitPolicy::Edge => $slf.edges.get_mut(&TypeId::of::<A>()),
            OrbitPolicy::Face => $slf.faces.get_mut(&TypeId::of::<A>()),
            OrbitPolicy::Custom(_) => $slf.others.get_mut(&TypeId::of::<A>()),
        };
        let $id = probably_storage
            .map(|m| m.downcast_mut::<<A as AttributeBind>::StorageType>())
            .flatten();
    };
}

/// **Attribute-specific methods**
impl AttrStorageManager {
    #[allow(clippy::missing_errors_doc)]
    /// Add a new storage to the manager.
    ///
    /// For a breakdown of the principles used for implementation, refer to the *Explanation*
    /// section of the [`AttrStorageManager`] documentation entry.
    ///
    /// # Arguments
    ///
    /// - `size: usize` -- Initial size of the new storage.
    ///
    /// ## Generic
    ///
    /// - `A: AttributeBind + 'static` -- Type of the attribute that will be stored.
    ///
    /// # Panics
    ///
    /// This function will panic if there is already a storage of attribute `A` in the manager.
    pub fn add_storage<A: AttributeBind + 'static>(&mut self, size: usize) {
        let typeid = TypeId::of::<A>();
        let new_storage = <A as AttributeBind>::StorageType::new(size);
        if match A::BIND_POLICY {
            OrbitPolicy::Vertex => self.vertices.insert(typeid, Box::new(new_storage)),
            OrbitPolicy::Edge => self.edges.insert(typeid, Box::new(new_storage)),
            OrbitPolicy::Face => self.faces.insert(typeid, Box::new(new_storage)),
            OrbitPolicy::Custom(_) => self.others.insert(typeid, Box::new(new_storage)),
        }
        .is_some()
        {
            eprintln!(
                "W: Storage of attribute `{}` already exists in the attribute storage manager",
                std::any::type_name::<A>()
            );
            eprintln!("   Continuing...");
        }
    }

    /// Extend the size of the storage of a given attribute.
    ///
    /// # Arguments
    ///
    /// - `length: usize` -- Length by which the storage should be extended.
    ///
    /// ## Generic
    ///
    /// - `A: AttributeBind` -- Attribute of which the storage should be extended.
    pub fn extend_storage<A: AttributeBind>(&mut self, length: usize) {
        get_storage_mut!(self, storage);
        if let Some(st) = storage {
            st.extend(length);
        } else {
            eprintln!(
                "W: could not extend storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
        }
    }

    /// Get a reference to the storage of a given attribute.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Attribute stored by the fetched storage.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    #[must_use = "unused getter result - please remove this method call"]
    pub fn get_storage<A: AttributeBind>(&self) -> Option<&<A as AttributeBind>::StorageType> {
        let probably_storage = match A::BIND_POLICY {
            OrbitPolicy::Vertex => &self.vertices[&TypeId::of::<A>()],
            OrbitPolicy::Edge => &self.edges[&TypeId::of::<A>()],
            OrbitPolicy::Face => &self.faces[&TypeId::of::<A>()],
            OrbitPolicy::Custom(_) => &self.others[&TypeId::of::<A>()],
        };
        probably_storage.downcast_ref::<<A as AttributeBind>::StorageType>()
    }

    /// Remove an entire attribute storage from the manager.
    ///
    /// This method is useful when implementing routines that uses attributes to run; Those can then be removed
    /// before the final result is returned.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Attribute stored by the fetched storage.
    pub fn remove_storage<A: AttributeBind>(&mut self) {
        // we could return it ?
        let _ = match A::BIND_POLICY {
            OrbitPolicy::Vertex => &self.vertices.remove(&TypeId::of::<A>()),
            OrbitPolicy::Edge => &self.edges.remove(&TypeId::of::<A>()),
            OrbitPolicy::Face => &self.faces.remove(&TypeId::of::<A>()),
            OrbitPolicy::Custom(_) => &self.others.remove(&TypeId::of::<A>()),
        };
    }

    /// Set the value of an attribute.
    ///
    /// # Arguments
    ///
    /// - `id: A::IdentifierType` -- Cell ID to which the attribute is associated.
    /// - `val: A` -- New value of the attribute for the given ID.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Type of the attribute being set.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    /// - the index lands out of bounds
    pub fn set_attribute<A: AttributeBind>(&self, id: A::IdentifierType, val: A) {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.set(id, val);
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
        }
    }

    /// Set the value of an attribute.
    ///
    /// # Arguments
    ///
    /// - `id: A::IdentifierType` -- Cell ID to which the attribute is associated.
    /// - `val: A` -- New value of the attribute for the given ID.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Type of the attribute being set.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - **there already is a value associated to the given ID for the specified attribute**
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    /// - the index lands out of bounds
    pub fn insert_attribute<A: AttributeBind>(&self, id: A::IdentifierType, val: A) {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.insert(id, val);
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
        }
    }

    /// Get the value of an attribute.
    ///
    /// # Arguments
    ///
    /// - `id: A::IdentifierType` -- Cell ID to which the attribute is associated.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Type of the attribute fetched.
    ///
    /// # Return
    ///
    /// The method may return:
    /// - `Some(val: A)` if there is an attribute associated with the specified index,
    /// - `None` if there is not.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    /// - the index lands out of bounds
    pub fn get_attribute<A: AttributeBind>(&self, id: A::IdentifierType) -> Option<A> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.get(id)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            None
        }
    }

    /// Set the value of an attribute.
    ///
    /// # Arguments
    ///
    /// - `id: A::IdentifierType` -- ID of the cell to which the attribute is associated.
    /// - `val: A` -- New value of the attribute for the given ID.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Type of the attribute being set.
    ///
    /// # Return
    ///
    /// The method should return:
    /// - `Some(val_old: A)` if there was an attribute associated with the specified index,
    /// - `None` if there was not.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    /// - the index lands out of bounds
    pub fn replace_attribute<A: AttributeBind>(&self, id: A::IdentifierType, val: A) -> Option<A> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.replace(id, val)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            None
        }
    }

    /// Remove the an item from an attribute storage.
    ///
    /// # Arguments
    ///
    /// - `id: A::IdentifierType` -- Cell ID to which the attribute is associated.
    ///
    /// # Generic
    ///
    /// - `A: AttributeBind` -- Type of the attribute fetched.
    ///
    /// # Return
    ///
    /// The method may return:
    /// - `Some(val: A)` if was is an attribute associated with the specified index,
    /// - `None` if there was not.
    ///
    /// # Panics
    ///
    /// This method may panic if:
    /// - there's no storage associated with the specified attribute
    /// - downcasting `Box<dyn UnknownAttributeStorage>` to `<A as AttributeBind>::StorageType` fails
    /// - the index lands out of bounds
    pub fn remove_attribute<A: AttributeBind>(&self, id: A::IdentifierType) -> Option<A> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.remove(id)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            None
        }
    }

    /// Merge given attribute values.
    ///
    /// # Arguments
    ///
    /// - `id_out: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in_lhs: DartIdentifier` -- Identifier of one attribute value to merge.
    /// - `id_in_rhs: DartIdentifier` -- Identifier of the other attribute value to merge.
    pub fn merge_attribute<A: AttributeBind>(
        &self,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.merge(id_out, id_in_lhs, id_in_rhs);
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
        }
    }

    /// Split given attribute value.
    ///
    /// # Arguments
    ///
    /// - `id_out_lhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_out_rhs: DartIdentifier` -- Identifier to write the result to.
    /// - `id_in: DartIdentifier` -- Identifier of the attribute value to split.
    pub fn split_attribute<A: AttributeBind>(
        &self,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.split(id_out_lhs, id_out_rhs, id_in);
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
        }
    }
}

/// Transactional methods
#[doc(hidden)]
#[allow(unused)]
impl AttrStorageManager {
    // merges

    pub(crate) fn merge_attributes_transac(
        &self,
        trans: &mut Transaction,
        orbit_policy: &OrbitPolicy,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        match orbit_policy {
            OrbitPolicy::Vertex => {
                self.merge_vertex_attributes_transac(trans, id_out, id_in_lhs, id_in_rhs)
            }
            OrbitPolicy::Edge => {
                self.merge_edge_attributes_transac(trans, id_out, id_in_lhs, id_in_rhs)
            }
            OrbitPolicy::Face => {
                self.merge_face_attributes_transac(trans, id_out, id_in_lhs, id_in_rhs)
            }
            OrbitPolicy::Custom(_) => self.merge_other_attributes_transac(
                trans,
                orbit_policy,
                id_out,
                id_in_lhs,
                id_in_rhs,
            ),
        }
    }

    pub(crate) fn merge_vertex_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.vertices.values() {
            storage.merge_transac(trans, id_out, id_in_lhs, id_in_rhs)?;
        }
        Ok(())
    }

    pub(crate) fn merge_edge_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.edges.values() {
            storage.merge_transac(trans, id_out, id_in_lhs, id_in_rhs)?;
        }
        Ok(())
    }

    pub(crate) fn merge_face_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.faces.values() {
            storage.merge_transac(trans, id_out, id_in_lhs, id_in_rhs)?;
        }
        Ok(())
    }

    pub(crate) fn merge_other_attributes_transac(
        &self,
        _trans: &mut Transaction,
        _orbit_policy: &OrbitPolicy,
        _id_out: DartIdType,
        _id_in_lhs: DartIdType,
        _id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        todo!("custom orbit binding is a special case that will be treated later")
    }

    // splits

    pub(crate) fn split_attributes_transac(
        &self,
        trans: &mut Transaction,
        orbit_policy: &OrbitPolicy,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) -> Result<(), StmError> {
        match orbit_policy {
            OrbitPolicy::Vertex => {
                self.split_vertex_attributes_transac(trans, id_out_lhs, id_out_rhs, id_in)
            }
            OrbitPolicy::Edge => {
                self.split_edge_attributes_transac(trans, id_out_lhs, id_out_rhs, id_in)
            }
            OrbitPolicy::Face => {
                self.split_face_attributes_transac(trans, id_out_lhs, id_out_rhs, id_in)
            }
            OrbitPolicy::Custom(_) => self.split_other_attributes_transac(
                trans,
                orbit_policy,
                id_out_lhs,
                id_out_rhs,
                id_in,
            ),
        }
    }

    pub(crate) fn split_vertex_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.vertices.values() {
            storage.split_transac(trans, id_out_lhs, id_out_rhs, id_in)?;
        }
        Ok(())
    }

    pub(crate) fn split_edge_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.edges.values() {
            storage.split_transac(trans, id_out_lhs, id_out_rhs, id_in)?;
        }
        Ok(())
    }

    pub(crate) fn split_face_attributes_transac(
        &self,
        trans: &mut Transaction,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) -> Result<(), StmError> {
        for storage in self.faces.values() {
            storage.split_transac(trans, id_out_lhs, id_out_rhs, id_in)?;
        }
        Ok(())
    }

    pub(crate) fn split_other_attributes_transac(
        &self,
        _trans: &mut Transaction,
        _orbit_policy: &OrbitPolicy,
        _id_out_lhs: DartIdType,
        _id_out_rhs: DartIdType,
        _id_in: DartIdType,
    ) -> Result<(), StmError> {
        todo!("custom orbit binding is a special case that will be treated later")
    }

    pub(crate) fn set_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id: A::IdentifierType,
        val: A,
    ) -> Result<(), StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.set_transac(trans, id, val)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(())
        }
    }

    pub(crate) fn insert_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id: A::IdentifierType,
        val: A,
    ) -> Result<(), StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.insert_transac(trans, id, val)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(())
        }
    }

    pub(crate) fn get_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id: A::IdentifierType,
    ) -> Result<Option<A>, StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.get_transac(trans, id)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(None)
        }
    }

    pub(crate) fn replace_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id: A::IdentifierType,
        val: A,
    ) -> Result<Option<A>, StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.replace_transac(trans, id, val)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(None)
        }
    }

    pub(crate) fn remove_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id: A::IdentifierType,
    ) -> Result<Option<A>, StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.remove_transac(trans, id)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(None)
        }
    }

    pub(crate) fn merge_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id_out: DartIdType,
        id_in_lhs: DartIdType,
        id_in_rhs: DartIdType,
    ) -> Result<(), StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.merge_transac(trans, id_out, id_in_lhs, id_in_rhs)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(())
        }
    }

    pub(crate) fn split_attribute_transac<A: AttributeBind>(
        &self,
        trans: &mut Transaction,
        id_out_lhs: DartIdType,
        id_out_rhs: DartIdType,
        id_in: DartIdType,
    ) -> Result<(), StmError> {
        get_storage!(self, storage);
        if let Some(st) = storage {
            st.split_transac(trans, id_out_lhs, id_out_rhs, id_in)
        } else {
            eprintln!(
                "W: could not update storage of attribute {} - storage not found",
                std::any::type_name::<A>()
            );
            Ok(())
        }
    }
}