diff --git a/crates/hir-ty/src/db.rs b/crates/hir-ty/src/db.rs index b385b1cafa..c4f7685cd1 100644 --- a/crates/hir-ty/src/db.rs +++ b/crates/hir-ty/src/db.rs @@ -116,6 +116,8 @@ pub trait HirDatabase: DefDatabase + Upcast { fn intern_impl_trait_id(&self, id: ImplTraitId) -> InternedOpaqueTyId; #[salsa::interned] fn intern_closure(&self, id: (DefWithBodyId, ExprId)) -> InternedClosureId; + #[salsa::interned] + fn intern_generator(&self, id: (DefWithBodyId, ExprId)) -> InternedGeneratorId; #[salsa::invoke(chalk_db::associated_ty_data_query)] fn associated_ty_data(&self, id: chalk_db::AssocTypeId) -> Arc; @@ -218,6 +220,10 @@ impl_intern_key!(InternedOpaqueTyId); pub struct InternedClosureId(salsa::InternId); impl_intern_key!(InternedClosureId); +#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] +pub struct InternedGeneratorId(salsa::InternId); +impl_intern_key!(InternedGeneratorId); + /// This exists just for Chalk, because Chalk just has a single `FnDefId` where /// we have different IDs for struct and enum variant constructors. #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)] diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs index 10ffde87ee..d351eb599c 100644 --- a/crates/hir-ty/src/infer.rs +++ b/crates/hir-ty/src/infer.rs @@ -332,7 +332,7 @@ pub struct InferenceResult { /// unresolved or missing subpatterns or subpatterns of mismatched types. pub type_of_pat: ArenaMap, type_mismatches: FxHashMap, - /// Interned Unknown to return references to. + /// Interned common types to return references to. standard_types: InternedStandardTypes, /// Stores the types which were implicitly dereferenced in pattern binding modes. pub pat_adjustments: FxHashMap>, @@ -412,6 +412,8 @@ pub(crate) struct InferenceContext<'a> { /// closures, but currently this is the only field that will change there, /// so it doesn't make sense. return_ty: Ty, + /// The resume type and the yield type, respectively, of the generator being inferred. + resume_yield_tys: Option<(Ty, Ty)>, diverges: Diverges, breakables: Vec, } @@ -476,6 +478,7 @@ impl<'a> InferenceContext<'a> { table: unify::InferenceTable::new(db, trait_env.clone()), trait_env, return_ty: TyKind::Error.intern(Interner), // set in collect_fn_signature + resume_yield_tys: None, db, owner, body, diff --git a/crates/hir-ty/src/infer/closure.rs b/crates/hir-ty/src/infer/closure.rs index 3ead929098..094e460dbf 100644 --- a/crates/hir-ty/src/infer/closure.rs +++ b/crates/hir-ty/src/infer/closure.rs @@ -12,6 +12,7 @@ use crate::{ use super::{Expectation, InferenceContext}; impl InferenceContext<'_> { + // This function handles both closures and generators. pub(super) fn deduce_closure_type_from_expectations( &mut self, closure_expr: ExprId, @@ -27,6 +28,11 @@ impl InferenceContext<'_> { // Deduction from where-clauses in scope, as well as fn-pointer coercion are handled here. let _ = self.coerce(Some(closure_expr), closure_ty, &expected_ty); + // Generators are not Fn* so return early. + if matches!(closure_ty.kind(Interner), TyKind::Generator(..)) { + return; + } + // Deduction based on the expected `dyn Fn` is done separately. if let TyKind::Dyn(dyn_ty) = expected_ty.kind(Interner) { if let Some(sig) = self.deduce_sig_from_dyn_ty(dyn_ty) { diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs index f0382846a6..e3d6be23e6 100644 --- a/crates/hir-ty/src/infer/expr.rs +++ b/crates/hir-ty/src/infer/expr.rs @@ -10,7 +10,10 @@ use chalk_ir::{ cast::Cast, fold::Shift, DebruijnIndex, GenericArgData, Mutability, TyVariableKind, }; use hir_def::{ - expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, LabelId, Literal, Statement, UnaryOp}, + expr::{ + ArithOp, Array, BinaryOp, ClosureKind, CmpOp, Expr, ExprId, LabelId, Literal, Statement, + UnaryOp, + }, generics::TypeOrConstParamData, path::{GenericArg, GenericArgs}, resolver::resolver_for_expr, @@ -216,7 +219,7 @@ impl<'a> InferenceContext<'a> { self.diverges = Diverges::Maybe; TyBuilder::unit() } - Expr::Closure { body, args, ret_type, arg_types, closure_kind: _ } => { + Expr::Closure { body, args, ret_type, arg_types, closure_kind } => { assert_eq!(args.len(), arg_types.len()); let mut sig_tys = Vec::new(); @@ -244,20 +247,40 @@ impl<'a> InferenceContext<'a> { ), }) .intern(Interner); - let closure_id = self.db.intern_closure((self.owner, tgt_expr)).into(); - let closure_ty = - TyKind::Closure(closure_id, Substitution::from1(Interner, sig_ty.clone())) - .intern(Interner); + + let (ty, resume_yield_tys) = if matches!(closure_kind, ClosureKind::Generator(_)) { + // FIXME: report error when there are more than 1 parameter. + let resume_ty = match sig_tys.first() { + // When `sig_tys.len() == 1` the first type is the return type, not the + // first parameter type. + Some(ty) if sig_tys.len() > 1 => ty.clone(), + _ => self.result.standard_types.unit.clone(), + }; + let yield_ty = self.table.new_type_var(); + + let subst = TyBuilder::subst_for_generator(self.db, self.owner) + .push(resume_ty.clone()) + .push(yield_ty.clone()) + .push(ret_ty.clone()) + .build(); + + let generator_id = self.db.intern_generator((self.owner, tgt_expr)).into(); + let generator_ty = TyKind::Generator(generator_id, subst).intern(Interner); + + (generator_ty, Some((resume_ty, yield_ty))) + } else { + let closure_id = self.db.intern_closure((self.owner, tgt_expr)).into(); + let closure_ty = + TyKind::Closure(closure_id, Substitution::from1(Interner, sig_ty.clone())) + .intern(Interner); + + (closure_ty, None) + }; // Eagerly try to relate the closure type with the expected // type, otherwise we often won't have enough information to // infer the body. - self.deduce_closure_type_from_expectations( - tgt_expr, - &closure_ty, - &sig_ty, - expected, - ); + self.deduce_closure_type_from_expectations(tgt_expr, &ty, &sig_ty, expected); // Now go through the argument patterns for (arg_pat, arg_ty) in args.iter().zip(sig_tys) { @@ -266,6 +289,8 @@ impl<'a> InferenceContext<'a> { let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone()); + let prev_resume_yield_tys = + mem::replace(&mut self.resume_yield_tys, resume_yield_tys); self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| { this.infer_expr_coerce(*body, &Expectation::has_type(ret_ty)); @@ -273,8 +298,9 @@ impl<'a> InferenceContext<'a> { self.diverges = prev_diverges; self.return_ty = prev_ret_ty; + self.resume_yield_tys = prev_resume_yield_tys; - closure_ty + ty } Expr::Call { callee, args, .. } => { let callee_ty = self.infer_expr(*callee, &Expectation::none()); @@ -423,11 +449,18 @@ impl<'a> InferenceContext<'a> { TyKind::Never.intern(Interner) } Expr::Yield { expr } => { - // FIXME: track yield type for coercion - if let Some(expr) = expr { - self.infer_expr(*expr, &Expectation::none()); + if let Some((resume_ty, yield_ty)) = self.resume_yield_tys.clone() { + if let Some(expr) = expr { + self.infer_expr_coerce(*expr, &Expectation::has_type(yield_ty)); + } else { + let unit = self.result.standard_types.unit.clone(); + let _ = self.coerce(Some(tgt_expr), &unit, &yield_ty); + } + resume_ty + } else { + // FIXME: report error (yield expr in non-generator) + TyKind::Error.intern(Interner) } - TyKind::Never.intern(Interner) } Expr::RecordLit { path, fields, spread, .. } => { let (ty, def_id) = self.resolve_variant(path.as_deref(), false); diff --git a/crates/hir-ty/src/mapping.rs b/crates/hir-ty/src/mapping.rs index d765fee0e1..f80fb39c1f 100644 --- a/crates/hir-ty/src/mapping.rs +++ b/crates/hir-ty/src/mapping.rs @@ -103,6 +103,18 @@ impl From for chalk_ir::ClosureId { } } +impl From> for crate::db::InternedGeneratorId { + fn from(id: chalk_ir::GeneratorId) -> Self { + Self::from_intern_id(id.0) + } +} + +impl From for chalk_ir::GeneratorId { + fn from(id: crate::db::InternedGeneratorId) -> Self { + chalk_ir::GeneratorId(id.as_intern_id()) + } +} + pub fn to_foreign_def_id(id: TypeAliasId) -> ForeignDefId { chalk_ir::ForeignDefId(salsa::InternKey::as_intern_id(&id)) }