Merge #8327

8327: Move `Ty` creation methods out of `Ty` (Chalk move preparation) r=flodiebold a=flodiebold

When we'll move to using `chalk_ir::Ty` (#8313), we won't be able to have our own inherent methods on `Ty` anymore, so we need to move the helpers elsewhere.
This adds a `TyBuilder` that allows easily constructing `Ty` and related types (`TraitRef`, `ProjectionTy`, `Substitution`). It also replaces `SubstsBuilder`. `TyBuilder` can construct different things based on its type parameter; e.g. if it has an `AdtId`, we're constructing an ADT type, but if it has a `TraitId`, we're constructing a `TraitRef`. The common thing for all of them is that we need to build a `Substitution`, so the API stays the same for all of them except at the beginning and end.

We also use `TyBuilder` to house various one-shot methods for constructing types, e.g. `TyBuilder::unit()`.

Co-authored-by: Florian Diebold <[email protected]>

1 files changed, 7 insertions, 7 deletions

diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index fbac51b05..541e6082f 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -22,7 +22,7 @@ use crate::{
     to_assoc_type_id, to_chalk_trait_id,
     utils::generics,
     AliasEq, AliasTy, BoundVar, CallableDefId, DebruijnIndex, FnDefId, ProjectionTy, Substitution,
-    TraitRef, Ty, TyKind, WhereClause,
+    TraitRef, Ty, TyBuilder, TyKind, WhereClause,
 };
 use mapping::{
     convert_where_clauses, generic_predicate_to_inline_bound, make_binders, TypeAliasAsValue,
@@ -300,7 +300,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         _closure_id: chalk_ir::ClosureId<Interner>,
         _substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Binders<chalk_ir::Ty<Interner>> {
-        let ty = Ty::unit().to_chalk(self.db);
+        let ty = TyBuilder::unit().to_chalk(self.db);
         make_binders(ty, 0)
     }
     fn closure_fn_substitution(
@@ -387,7 +387,7 @@ pub(crate) fn associated_ty_data_query(
     // Lower bounds -- we could/should maybe move this to a separate query in `lower`
     let type_alias_data = db.type_alias_data(type_alias);
     let generic_params = generics(db.upcast(), type_alias.into());
-    let bound_vars = Substitution::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+    let bound_vars = generic_params.bound_vars_subst(DebruijnIndex::INNERMOST);
     let resolver = hir_def::resolver::HasResolver::resolver(type_alias, db.upcast());
     let ctx = crate::TyLoweringContext::new(db, &resolver)
         .with_type_param_mode(crate::lower::TypeParamLoweringMode::Variable);
@@ -421,7 +421,7 @@ pub(crate) fn trait_datum_query(
     let trait_data = db.trait_data(trait_);
     debug!("trait {:?} = {:?}", trait_id, trait_data.name);
     let generic_params = generics(db.upcast(), trait_.into());
-    let bound_vars = Substitution::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+    let bound_vars = generic_params.bound_vars_subst(DebruijnIndex::INNERMOST);
     let flags = rust_ir::TraitFlags {
         auto: trait_data.is_auto,
         upstream: trait_.lookup(db.upcast()).container.krate() != krate,
@@ -490,7 +490,7 @@ pub(crate) fn struct_datum_query(
     let upstream = adt_id.module(db.upcast()).krate() != krate;
     let where_clauses = {
         let generic_params = generics(db.upcast(), adt_id.into());
-        let bound_vars = Substitution::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+        let bound_vars = generic_params.bound_vars_subst(DebruijnIndex::INNERMOST);
         convert_where_clauses(db, adt_id.into(), &bound_vars)
     };
     let flags = rust_ir::AdtFlags {
@@ -539,7 +539,7 @@ fn impl_def_datum(
     let impl_data = db.impl_data(impl_id);
 
     let generic_params = generics(db.upcast(), impl_id.into());
-    let bound_vars = Substitution::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+    let bound_vars = generic_params.bound_vars_subst(DebruijnIndex::INNERMOST);
     let trait_ = trait_ref.hir_trait_id();
     let impl_type = if impl_id.lookup(db.upcast()).container.krate() == krate {
         rust_ir::ImplType::Local
@@ -629,7 +629,7 @@ pub(crate) fn fn_def_datum_query(
     let callable_def: CallableDefId = from_chalk(db, fn_def_id);
     let generic_params = generics(db.upcast(), callable_def.into());
     let sig = db.callable_item_signature(callable_def);
-    let bound_vars = Substitution::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+    let bound_vars = generic_params.bound_vars_subst(DebruijnIndex::INNERMOST);
     let where_clauses = convert_where_clauses(db, callable_def.into(), &bound_vars);
     let bound = rust_ir::FnDefDatumBound {
         // Note: Chalk doesn't actually use this information yet as far as I am aware, but we provide it anyway