aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_hir/src/code_model_api.rs
blob: da0f1ec94d7be0d2b936b07d041eef008057c4fc (plain)
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
use std::sync::Arc;

use relative_path::RelativePathBuf;
use ra_db::{CrateId, SourceRootId, Edition};
use ra_syntax::{ast::self, TreeArc, SyntaxNode};

use crate::{
    Name, ScopesWithSyntaxMapping, Ty, HirFileId,
    HirDatabase, PersistentHirDatabase,
    type_ref::TypeRef,
    nameres::{ModuleScope, Namespace, lower::ImportId},
    expr::{Body, BodySyntaxMapping},
    ty::InferenceResult,
    adt::{EnumVariantId, StructFieldId, VariantDef},
    generics::GenericParams,
    docs::{Documentation, Docs, docs_from_ast},
    module_tree::ModuleId,
    ids::{FunctionId, StructId, EnumId, AstItemDef, ConstId, StaticId, TraitId, TypeId},
    impl_block::ImplBlock,
    resolve::Resolver,
};

/// hir::Crate describes a single crate. It's the main interface with which
/// a crate's dependencies interact. Mostly, it should be just a proxy for the
/// root module.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Crate {
    pub(crate) crate_id: CrateId,
}

#[derive(Debug)]
pub struct CrateDependency {
    pub krate: Crate,
    pub name: Name,
}

impl Crate {
    pub fn crate_id(&self) -> CrateId {
        self.crate_id
    }

    pub fn dependencies(&self, db: &impl PersistentHirDatabase) -> Vec<CrateDependency> {
        self.dependencies_impl(db)
    }

    pub fn root_module(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
        self.root_module_impl(db)
    }

    pub fn edition(&self, db: &impl PersistentHirDatabase) -> Edition {
        let crate_graph = db.crate_graph();
        crate_graph.edition(self.crate_id)
    }

    // TODO: should this be in source_binder?
    pub fn source_root_crates(
        db: &impl PersistentHirDatabase,
        source_root: SourceRootId,
    ) -> Vec<Crate> {
        let crate_ids = db.source_root_crates(source_root);
        crate_ids.iter().map(|&crate_id| Crate { crate_id }).collect()
    }
}

#[derive(Debug)]
pub enum Def {
    Item,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Module {
    pub(crate) krate: Crate,
    pub(crate) module_id: ModuleId,
}

/// The defs which can be visible in the module.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ModuleDef {
    Module(Module),
    Function(Function),
    Struct(Struct),
    Enum(Enum),
    // Can't be directly declared, but can be imported.
    EnumVariant(EnumVariant),
    Const(Const),
    Static(Static),
    Trait(Trait),
    TypeAlias(TypeAlias),
}
impl_froms!(
    ModuleDef: Module,
    Function,
    Struct,
    Enum,
    EnumVariant,
    Const,
    Static,
    Trait,
    TypeAlias
);

pub enum ModuleSource {
    SourceFile(TreeArc<ast::SourceFile>),
    Module(TreeArc<ast::Module>),
}

#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub enum Problem {
    UnresolvedModule { candidate: RelativePathBuf },
    NotDirOwner { move_to: RelativePathBuf, candidate: RelativePathBuf },
}

impl Module {
    /// Name of this module.
    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
        self.name_impl(db)
    }

    /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
    pub fn definition_source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, ModuleSource) {
        self.definition_source_impl(db)
    }

    /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
    /// `None` for the crate root.
    pub fn declaration_source(
        &self,
        db: &impl HirDatabase,
    ) -> Option<(HirFileId, TreeArc<ast::Module>)> {
        self.declaration_source_impl(db)
    }

    /// Returns the syntax of the last path segment corresponding to this import
    pub fn import_source(
        &self,
        db: &impl HirDatabase,
        import: ImportId,
    ) -> TreeArc<ast::PathSegment> {
        self.import_source_impl(db, import)
    }

    /// Returns the crate this module is part of.
    pub fn krate(&self, _db: &impl PersistentHirDatabase) -> Option<Crate> {
        Some(self.krate)
    }

    /// Topmost parent of this module. Every module has a `crate_root`, but some
    /// might be missing `krate`. This can happen if a module's file is not included
    /// in the module tree of any target in `Cargo.toml`.
    pub fn crate_root(&self, db: &impl PersistentHirDatabase) -> Module {
        self.crate_root_impl(db)
    }

    /// Finds a child module with the specified name.
    pub fn child(&self, db: &impl HirDatabase, name: &Name) -> Option<Module> {
        self.child_impl(db, name)
    }

    /// Iterates over all child modules.
    pub fn children(&self, db: &impl PersistentHirDatabase) -> impl Iterator<Item = Module> {
        self.children_impl(db)
    }

    /// Finds a parent module.
    pub fn parent(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
        self.parent_impl(db)
    }

    pub fn path_to_root(&self, db: &impl HirDatabase) -> Vec<Module> {
        let mut res = vec![self.clone()];
        let mut curr = self.clone();
        while let Some(next) = curr.parent(db) {
            res.push(next.clone());
            curr = next
        }
        res
    }

    /// Returns a `ModuleScope`: a set of items, visible in this module.
    pub fn scope(&self, db: &impl HirDatabase) -> ModuleScope {
        db.item_map(self.krate)[self.module_id].clone()
    }

    pub fn problems(&self, db: &impl HirDatabase) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
        self.problems_impl(db)
    }

    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        let item_map = db.item_map(self.krate);
        Resolver::default().push_module_scope(item_map, *self)
    }

    pub fn declarations(self, db: &impl HirDatabase) -> Vec<ModuleDef> {
        let (lowered_module, _) = db.lower_module(self);
        lowered_module
            .declarations
            .values()
            .cloned()
            .flat_map(|per_ns| {
                per_ns.take_types().into_iter().chain(per_ns.take_values().into_iter())
            })
            .collect()
    }

    pub fn impl_blocks(self, db: &impl HirDatabase) -> Vec<ImplBlock> {
        let module_impl_blocks = db.impls_in_module(self);
        module_impl_blocks
            .impls
            .iter()
            .map(|(impl_id, _)| ImplBlock::from_id(self, impl_id))
            .collect()
    }
}

impl Docs for Module {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        self.declaration_source(db).and_then(|it| docs_from_ast(&*it.1))
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StructField {
    pub(crate) parent: VariantDef,
    pub(crate) id: StructFieldId,
}

#[derive(Debug)]
pub enum FieldSource {
    Named(TreeArc<ast::NamedFieldDef>),
    Pos(TreeArc<ast::PosFieldDef>),
}

impl StructField {
    pub fn name(&self, db: &impl HirDatabase) -> Name {
        self.parent.variant_data(db).fields().unwrap()[self.id].name.clone()
    }

    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, FieldSource) {
        self.source_impl(db)
    }

    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
        db.type_for_field(*self)
    }

    pub fn parent_def(&self, _db: &impl HirDatabase) -> VariantDef {
        self.parent
    }
}

impl Docs for StructField {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        match self.source(db).1 {
            FieldSource::Named(named) => docs_from_ast(&*named),
            FieldSource::Pos(..) => return None,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Struct {
    pub(crate) id: StructId,
}

impl Struct {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::StructDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl HirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
        db.struct_data(*self).name.clone()
    }

    pub fn fields(&self, db: &impl HirDatabase) -> Vec<StructField> {
        db.struct_data(*self)
            .variant_data
            .fields()
            .into_iter()
            .flat_map(|it| it.iter())
            .map(|(id, _)| StructField { parent: (*self).into(), id })
            .collect()
    }

    pub fn field(&self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
        db.struct_data(*self)
            .variant_data
            .fields()
            .into_iter()
            .flat_map(|it| it.iter())
            .find(|(_id, data)| data.name == *name)
            .map(|(id, _)| StructField { parent: (*self).into(), id })
    }

    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }

    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
        db.type_for_def((*self).into(), Namespace::Types)
    }

    pub fn constructor_ty(&self, db: &impl HirDatabase) -> Ty {
        db.type_for_def((*self).into(), Namespace::Values)
    }

    // TODO move to a more general type
    /// Builds a resolver for type references inside this struct.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        let r = self.module(db).resolver(db);
        // ...and add generic params, if present
        let p = self.generic_params(db);
        let r = if !p.params.is_empty() { r.push_generic_params_scope(p) } else { r };
        r
    }
}

impl Docs for Struct {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Enum {
    pub(crate) id: EnumId,
}

impl Enum {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::EnumDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl HirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
        db.enum_data(*self).name.clone()
    }

    pub fn variants(&self, db: &impl PersistentHirDatabase) -> Vec<EnumVariant> {
        db.enum_data(*self)
            .variants
            .iter()
            .map(|(id, _)| EnumVariant { parent: *self, id })
            .collect()
    }

    pub fn variant(&self, db: &impl PersistentHirDatabase, name: &Name) -> Option<EnumVariant> {
        db.enum_data(*self)
            .variants
            .iter()
            .find(|(_id, data)| data.name.as_ref() == Some(name))
            .map(|(id, _)| EnumVariant { parent: *self, id })
    }

    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }

    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
        db.type_for_def((*self).into(), Namespace::Types)
    }

    // TODO: move to a more general type
    /// Builds a resolver for type references inside this struct.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        let r = self.module(db).resolver(db);
        // ...and add generic params, if present
        let p = self.generic_params(db);
        let r = if !p.params.is_empty() { r.push_generic_params_scope(p) } else { r };
        r
    }
}

impl Docs for Enum {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct EnumVariant {
    pub(crate) parent: Enum,
    pub(crate) id: EnumVariantId,
}

impl EnumVariant {
    pub fn source(
        &self,
        db: &impl PersistentHirDatabase,
    ) -> (HirFileId, TreeArc<ast::EnumVariant>) {
        self.source_impl(db)
    }
    pub fn module(&self, db: &impl HirDatabase) -> Module {
        self.parent.module(db)
    }
    pub fn parent_enum(&self, _db: &impl PersistentHirDatabase) -> Enum {
        self.parent
    }

    pub fn name(&self, db: &impl PersistentHirDatabase) -> Option<Name> {
        db.enum_data(self.parent).variants[self.id].name.clone()
    }

    pub fn fields(&self, db: &impl HirDatabase) -> Vec<StructField> {
        self.variant_data(db)
            .fields()
            .into_iter()
            .flat_map(|it| it.iter())
            .map(|(id, _)| StructField { parent: (*self).into(), id })
            .collect()
    }

    pub fn field(&self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
        self.variant_data(db)
            .fields()
            .into_iter()
            .flat_map(|it| it.iter())
            .find(|(_id, data)| data.name == *name)
            .map(|(id, _)| StructField { parent: (*self).into(), id })
    }
}

impl Docs for EnumVariant {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Function {
    pub(crate) id: FunctionId,
}

/// The declared signature of a function.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct FnSignature {
    pub(crate) name: Name,
    pub(crate) params: Vec<TypeRef>,
    pub(crate) ret_type: TypeRef,
    /// True if the first param is `self`. This is relevant to decide whether this
    /// can be called as a method.
    pub(crate) has_self_param: bool,
}

impl FnSignature {
    pub fn name(&self) -> &Name {
        &self.name
    }

    pub fn params(&self) -> &[TypeRef] {
        &self.params
    }

    pub fn ret_type(&self) -> &TypeRef {
        &self.ret_type
    }

    /// True if the first arg is `self`. This is relevant to decide whether this
    /// can be called as a method.
    pub fn has_self_param(&self) -> bool {
        self.has_self_param
    }
}

impl Function {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::FnDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn name(&self, db: &impl HirDatabase) -> Name {
        self.signature(db).name.clone()
    }

    pub fn body_syntax_mapping(&self, db: &impl HirDatabase) -> Arc<BodySyntaxMapping> {
        db.body_syntax_mapping(*self)
    }

    pub fn body(&self, db: &impl HirDatabase) -> Arc<Body> {
        db.body_hir(*self)
    }

    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
        db.type_for_def((*self).into(), Namespace::Values)
    }

    pub fn scopes(&self, db: &impl HirDatabase) -> ScopesWithSyntaxMapping {
        let scopes = db.expr_scopes(*self);
        let syntax_mapping = db.body_syntax_mapping(*self);
        ScopesWithSyntaxMapping { scopes, syntax_mapping }
    }

    pub fn signature(&self, db: &impl HirDatabase) -> Arc<FnSignature> {
        db.fn_signature(*self)
    }

    pub fn infer(&self, db: &impl HirDatabase) -> Arc<InferenceResult> {
        db.infer(*self)
    }

    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }

    /// The containing impl block, if this is a method.
    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
        let module_impls = db.impls_in_module(self.module(db));
        ImplBlock::containing(module_impls, (*self).into())
    }

    // TODO: move to a more general type for 'body-having' items
    /// Builds a resolver for code inside this item.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        let r = self
            .impl_block(db)
            .map(|ib| ib.resolver(db))
            .unwrap_or_else(|| self.module(db).resolver(db));
        // ...and add generic params, if present
        let p = self.generic_params(db);
        let r = if !p.params.is_empty() { r.push_generic_params_scope(p) } else { r };
        r
    }
}

impl Docs for Function {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Const {
    pub(crate) id: ConstId,
}

impl Const {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::ConstDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn signature(&self, db: &impl HirDatabase) -> Arc<ConstSignature> {
        db.const_signature(*self)
    }

    /// The containing impl block, if this is a method.
    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
        let module_impls = db.impls_in_module(self.module(db));
        ImplBlock::containing(module_impls, (*self).into())
    }

    // TODO: move to a more general type for 'body-having' items
    /// Builds a resolver for code inside this item.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        let r = self
            .impl_block(db)
            .map(|ib| ib.resolver(db))
            .unwrap_or_else(|| self.module(db).resolver(db));
        r
    }
}

impl Docs for Const {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

/// The declared signature of a const.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ConstSignature {
    pub(crate) name: Name,
    pub(crate) type_ref: TypeRef,
}

impl ConstSignature {
    pub fn name(&self) -> &Name {
        &self.name
    }

    pub fn type_ref(&self) -> &TypeRef {
        &self.type_ref
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Static {
    pub(crate) id: StaticId,
}

impl Static {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::StaticDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn signature(&self, db: &impl HirDatabase) -> Arc<ConstSignature> {
        db.static_signature(*self)
    }

    /// Builds a resolver for code inside this item.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        self.module(db).resolver(db)
    }
}

impl Docs for Static {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Trait {
    pub(crate) id: TraitId,
}

impl Trait {
    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::TraitDef>) {
        self.id.source(db)
    }

    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
        self.id.module(db)
    }

    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }
}

impl Docs for Trait {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeAlias {
    pub(crate) id: TypeId,
}

impl TypeAlias {
    pub fn source(
        &self,
        db: &impl PersistentHirDatabase,
    ) -> (HirFileId, TreeArc<ast::TypeAliasDef>) {
        self.id.source(db)
    }

    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }

    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
        self.id.module(db)
    }

    /// The containing impl block, if this is a method.
    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
        let module_impls = db.impls_in_module(self.module(db));
        ImplBlock::containing(module_impls, (*self).into())
    }

    pub fn type_ref(self, db: &impl PersistentHirDatabase) -> Arc<TypeRef> {
        db.type_alias_ref(self)
    }

    /// Builds a resolver for the type references in this type alias.
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
        // take the outer scope...
        let r = self
            .impl_block(db)
            .map(|ib| ib.resolver(db))
            .unwrap_or_else(|| self.module(db).resolver(db));
        // ...and add generic params, if present
        let p = self.generic_params(db);
        let r = if !p.params.is_empty() { r.push_generic_params_scope(p) } else { r };
        r
    }
}

impl Docs for TypeAlias {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        docs_from_ast(&*self.source(db).1)
    }
}