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, 2 insertions, 2 deletions

diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index 559ea31a0..993772aac 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs
@@ -13,7 +13,7 @@ use syntax::ast::{self, NameOwner};
 
 use crate::{
     Adt, Const, ConstParam, Enum, Field, Function, GenericParam, HasVisibility, LifetimeParam,
-    Module, Static, Struct, Substitution, Trait, Type, TypeAlias, TypeParam, Union, Variant,
+    Module, Static, Struct, Trait, TyBuilder, Type, TypeAlias, TypeParam, Union, Variant,
 };
 
 impl HirDisplay for Function {
@@ -234,7 +234,7 @@ impl HirDisplay for TypeParam {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         write!(f, "{}", self.name(f.db))?;
         let bounds = f.db.generic_predicates_for_param(self.id);
-        let substs = Substitution::type_params(f.db, self.id.parent);
+        let substs = TyBuilder::type_params_subst(f.db, self.id.parent);
         let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
         if !(predicates.is_empty() || f.omit_verbose_types()) {
             write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;