|
| 1 | +use chalk_ir::{cast::Cast as _, BoundVar, DebruijnIndex}; |
| 2 | +use hir_def::{ |
| 3 | + db::DefDatabase, |
| 4 | + generics::{ |
| 5 | + GenericParamDataRef, GenericParams, LifetimeParamData, TypeOrConstParamData, |
| 6 | + TypeParamProvenance, |
| 7 | + }, |
| 8 | + ConstParamId, GenericDefId, GenericParamId, ItemContainerId, LifetimeParamId, Lookup, |
| 9 | + TypeOrConstParamId, TypeParamId, |
| 10 | +}; |
| 11 | +use intern::Interned; |
| 12 | + |
| 13 | +use crate::{db::HirDatabase, Interner, Substitution}; |
| 14 | + |
| 15 | +pub(crate) fn generics(db: &dyn DefDatabase, def: GenericDefId) -> Generics { |
| 16 | + let parent_generics = parent_generic_def(db, def).map(|def| Box::new(generics(db, def))); |
| 17 | + Generics { def, params: db.generic_params(def), parent_generics } |
| 18 | +} |
| 19 | +#[derive(Clone, Debug)] |
| 20 | +pub(crate) struct Generics { |
| 21 | + def: GenericDefId, |
| 22 | + pub(crate) params: Interned<GenericParams>, |
| 23 | + parent_generics: Option<Box<Generics>>, |
| 24 | +} |
| 25 | + |
| 26 | +impl Generics { |
| 27 | + pub(crate) fn iter_id(&self) -> impl Iterator<Item = GenericParamId> + '_ { |
| 28 | + self.iter().map(|(id, _)| id) |
| 29 | + } |
| 30 | + |
| 31 | + pub(crate) fn def(&self) -> GenericDefId { |
| 32 | + self.def |
| 33 | + } |
| 34 | + |
| 35 | + /// Iterator over types and const params of self, then parent. |
| 36 | + pub(crate) fn iter<'a>( |
| 37 | + &'a self, |
| 38 | + ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'a>)> + 'a { |
| 39 | + let from_toc_id = |it: &'a Generics| { |
| 40 | + move |(local_id, p): (_, &'a TypeOrConstParamData)| { |
| 41 | + let id = TypeOrConstParamId { parent: it.def, local_id }; |
| 42 | + match p { |
| 43 | + TypeOrConstParamData::TypeParamData(p) => ( |
| 44 | + GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)), |
| 45 | + GenericParamDataRef::TypeParamData(p), |
| 46 | + ), |
| 47 | + TypeOrConstParamData::ConstParamData(p) => ( |
| 48 | + GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)), |
| 49 | + GenericParamDataRef::ConstParamData(p), |
| 50 | + ), |
| 51 | + } |
| 52 | + } |
| 53 | + }; |
| 54 | + |
| 55 | + let from_lt_id = |it: &'a Generics| { |
| 56 | + move |(local_id, p): (_, &'a LifetimeParamData)| { |
| 57 | + ( |
| 58 | + GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }), |
| 59 | + GenericParamDataRef::LifetimeParamData(p), |
| 60 | + ) |
| 61 | + } |
| 62 | + }; |
| 63 | + |
| 64 | + let lt_iter = self.params.iter_lt().map(from_lt_id(self)); |
| 65 | + self.params |
| 66 | + .iter_type_or_consts() |
| 67 | + .map(from_toc_id(self)) |
| 68 | + .chain(lt_iter) |
| 69 | + .chain(self.iter_parent()) |
| 70 | + } |
| 71 | + |
| 72 | + /// Iterate over types and const params without parent params. |
| 73 | + pub(crate) fn iter_self<'a>( |
| 74 | + &'a self, |
| 75 | + ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'a>)> + 'a { |
| 76 | + let from_toc_id = |it: &'a Generics| { |
| 77 | + move |(local_id, p): (_, &'a TypeOrConstParamData)| { |
| 78 | + let id = TypeOrConstParamId { parent: it.def, local_id }; |
| 79 | + match p { |
| 80 | + TypeOrConstParamData::TypeParamData(p) => ( |
| 81 | + GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)), |
| 82 | + GenericParamDataRef::TypeParamData(p), |
| 83 | + ), |
| 84 | + TypeOrConstParamData::ConstParamData(p) => ( |
| 85 | + GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)), |
| 86 | + GenericParamDataRef::ConstParamData(p), |
| 87 | + ), |
| 88 | + } |
| 89 | + } |
| 90 | + }; |
| 91 | + |
| 92 | + let from_lt_id = |it: &'a Generics| { |
| 93 | + move |(local_id, p): (_, &'a LifetimeParamData)| { |
| 94 | + ( |
| 95 | + GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }), |
| 96 | + GenericParamDataRef::LifetimeParamData(p), |
| 97 | + ) |
| 98 | + } |
| 99 | + }; |
| 100 | + |
| 101 | + self.params |
| 102 | + .iter_type_or_consts() |
| 103 | + .map(from_toc_id(self)) |
| 104 | + .chain(self.params.iter_lt().map(from_lt_id(self))) |
| 105 | + } |
| 106 | + |
| 107 | + /// Iterator over types and const params of parent. |
| 108 | + pub(crate) fn iter_parent( |
| 109 | + &self, |
| 110 | + ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'_>)> + '_ { |
| 111 | + self.parent_generics().into_iter().flat_map(|it| { |
| 112 | + let from_toc_id = move |(local_id, p)| { |
| 113 | + let p: &_ = p; |
| 114 | + let id = TypeOrConstParamId { parent: it.def, local_id }; |
| 115 | + match p { |
| 116 | + TypeOrConstParamData::TypeParamData(p) => ( |
| 117 | + GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)), |
| 118 | + GenericParamDataRef::TypeParamData(p), |
| 119 | + ), |
| 120 | + TypeOrConstParamData::ConstParamData(p) => ( |
| 121 | + GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)), |
| 122 | + GenericParamDataRef::ConstParamData(p), |
| 123 | + ), |
| 124 | + } |
| 125 | + }; |
| 126 | + |
| 127 | + let from_lt_id = move |(local_id, p): (_, _)| { |
| 128 | + ( |
| 129 | + GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }), |
| 130 | + GenericParamDataRef::LifetimeParamData(p), |
| 131 | + ) |
| 132 | + }; |
| 133 | + let lt_iter = it.params.iter_lt().map(from_lt_id); |
| 134 | + it.params.iter_type_or_consts().map(from_toc_id).chain(lt_iter) |
| 135 | + }) |
| 136 | + } |
| 137 | + |
| 138 | + /// Returns total number of generic parameters in scope, including those from parent. |
| 139 | + pub(crate) fn len(&self) -> usize { |
| 140 | + let parent = self.parent_generics().map_or(0, Generics::len); |
| 141 | + let child = self.params.len(); |
| 142 | + parent + child |
| 143 | + } |
| 144 | + |
| 145 | + /// Returns numbers of generic parameters excluding those from parent. |
| 146 | + pub(crate) fn len_self(&self) -> usize { |
| 147 | + self.params.len() |
| 148 | + } |
| 149 | + |
| 150 | + /// Returns number of generic parameter excluding those from parent |
| 151 | + fn len_type_and_const_params(&self) -> usize { |
| 152 | + self.params.type_or_consts.len() |
| 153 | + } |
| 154 | + |
| 155 | + /// (parent total, self param, type params, const params, impl trait list, lifetimes) |
| 156 | + pub(crate) fn provenance_split(&self) -> (usize, usize, usize, usize, usize, usize) { |
| 157 | + let mut self_params = 0; |
| 158 | + let mut type_params = 0; |
| 159 | + let mut impl_trait_params = 0; |
| 160 | + let mut const_params = 0; |
| 161 | + let mut lifetime_params = 0; |
| 162 | + self.params.iter_type_or_consts().for_each(|(_, data)| match data { |
| 163 | + TypeOrConstParamData::TypeParamData(p) => match p.provenance { |
| 164 | + TypeParamProvenance::TypeParamList => type_params += 1, |
| 165 | + TypeParamProvenance::TraitSelf => self_params += 1, |
| 166 | + TypeParamProvenance::ArgumentImplTrait => impl_trait_params += 1, |
| 167 | + }, |
| 168 | + TypeOrConstParamData::ConstParamData(_) => const_params += 1, |
| 169 | + }); |
| 170 | + |
| 171 | + self.params.iter_lt().for_each(|(_, _)| lifetime_params += 1); |
| 172 | + |
| 173 | + let parent_len = self.parent_generics().map_or(0, Generics::len); |
| 174 | + (parent_len, self_params, type_params, const_params, impl_trait_params, lifetime_params) |
| 175 | + } |
| 176 | + |
| 177 | + pub(crate) fn type_or_const_param_idx(&self, param: TypeOrConstParamId) -> Option<usize> { |
| 178 | + Some(self.find_type_or_const_param(param)?.0) |
| 179 | + } |
| 180 | + |
| 181 | + fn find_type_or_const_param( |
| 182 | + &self, |
| 183 | + param: TypeOrConstParamId, |
| 184 | + ) -> Option<(usize, &TypeOrConstParamData)> { |
| 185 | + if param.parent == self.def { |
| 186 | + let idx = param.local_id.into_raw().into_u32() as usize; |
| 187 | + if idx >= self.params.type_or_consts.len() { |
| 188 | + return None; |
| 189 | + } |
| 190 | + Some((idx, &self.params.type_or_consts[param.local_id])) |
| 191 | + } else { |
| 192 | + self.parent_generics() |
| 193 | + .and_then(|g| g.find_type_or_const_param(param)) |
| 194 | + // Remember that parent parameters come after parameters for self. |
| 195 | + .map(|(idx, data)| (self.len_self() + idx, data)) |
| 196 | + } |
| 197 | + } |
| 198 | + |
| 199 | + pub(crate) fn lifetime_idx(&self, lifetime: LifetimeParamId) -> Option<usize> { |
| 200 | + Some(self.find_lifetime(lifetime)?.0) |
| 201 | + } |
| 202 | + |
| 203 | + fn find_lifetime(&self, lifetime: LifetimeParamId) -> Option<(usize, &LifetimeParamData)> { |
| 204 | + if lifetime.parent == self.def { |
| 205 | + let idx = lifetime.local_id.into_raw().into_u32() as usize; |
| 206 | + if idx >= self.params.lifetimes.len() { |
| 207 | + return None; |
| 208 | + } |
| 209 | + Some(( |
| 210 | + self.len_type_and_const_params() + idx, |
| 211 | + &self.params.lifetimes[lifetime.local_id], |
| 212 | + )) |
| 213 | + } else { |
| 214 | + self.parent_generics() |
| 215 | + .and_then(|g| g.find_lifetime(lifetime)) |
| 216 | + .map(|(idx, data)| (self.len_self() + idx, data)) |
| 217 | + } |
| 218 | + } |
| 219 | + |
| 220 | + pub(crate) fn parent_generics(&self) -> Option<&Generics> { |
| 221 | + self.parent_generics.as_deref() |
| 222 | + } |
| 223 | + |
| 224 | + pub(crate) fn parent_or_self(&self) -> &Generics { |
| 225 | + self.parent_generics.as_deref().unwrap_or(self) |
| 226 | + } |
| 227 | + |
| 228 | + /// Returns a Substitution that replaces each parameter by a bound variable. |
| 229 | + pub(crate) fn bound_vars_subst( |
| 230 | + &self, |
| 231 | + db: &dyn HirDatabase, |
| 232 | + debruijn: DebruijnIndex, |
| 233 | + ) -> Substitution { |
| 234 | + Substitution::from_iter( |
| 235 | + Interner, |
| 236 | + self.iter_id().enumerate().map(|(idx, id)| match id { |
| 237 | + GenericParamId::ConstParamId(id) => BoundVar::new(debruijn, idx) |
| 238 | + .to_const(Interner, db.const_param_ty(id)) |
| 239 | + .cast(Interner), |
| 240 | + GenericParamId::TypeParamId(_) => { |
| 241 | + BoundVar::new(debruijn, idx).to_ty(Interner).cast(Interner) |
| 242 | + } |
| 243 | + GenericParamId::LifetimeParamId(_) => { |
| 244 | + BoundVar::new(debruijn, idx).to_lifetime(Interner).cast(Interner) |
| 245 | + } |
| 246 | + }), |
| 247 | + ) |
| 248 | + } |
| 249 | + |
| 250 | + /// Returns a Substitution that replaces each parameter by itself (i.e. `Ty::Param`). |
| 251 | + pub(crate) fn placeholder_subst(&self, db: &dyn HirDatabase) -> Substitution { |
| 252 | + Substitution::from_iter( |
| 253 | + Interner, |
| 254 | + self.iter_id().map(|id| match id { |
| 255 | + GenericParamId::TypeParamId(id) => { |
| 256 | + crate::to_placeholder_idx(db, id.into()).to_ty(Interner).cast(Interner) |
| 257 | + } |
| 258 | + GenericParamId::ConstParamId(id) => crate::to_placeholder_idx(db, id.into()) |
| 259 | + .to_const(Interner, db.const_param_ty(id)) |
| 260 | + .cast(Interner), |
| 261 | + GenericParamId::LifetimeParamId(id) => { |
| 262 | + crate::lt_to_placeholder_idx(db, id).to_lifetime(Interner).cast(Interner) |
| 263 | + } |
| 264 | + }), |
| 265 | + ) |
| 266 | + } |
| 267 | +} |
| 268 | + |
| 269 | +fn parent_generic_def(db: &dyn DefDatabase, def: GenericDefId) -> Option<GenericDefId> { |
| 270 | + let container = match def { |
| 271 | + GenericDefId::FunctionId(it) => it.lookup(db).container, |
| 272 | + GenericDefId::TypeAliasId(it) => it.lookup(db).container, |
| 273 | + GenericDefId::ConstId(it) => it.lookup(db).container, |
| 274 | + GenericDefId::EnumVariantId(it) => return Some(it.lookup(db).parent.into()), |
| 275 | + GenericDefId::AdtId(_) |
| 276 | + | GenericDefId::TraitId(_) |
| 277 | + | GenericDefId::ImplId(_) |
| 278 | + | GenericDefId::TraitAliasId(_) => return None, |
| 279 | + }; |
| 280 | + |
| 281 | + match container { |
| 282 | + ItemContainerId::ImplId(it) => Some(it.into()), |
| 283 | + ItemContainerId::TraitId(it) => Some(it.into()), |
| 284 | + ItemContainerId::ModuleId(_) | ItemContainerId::ExternBlockId(_) => None, |
| 285 | + } |
| 286 | +} |
0 commit comments