Make ToChalk implementations identity

2 files changed, 42 insertions, 272 deletions

diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 7d87741b8..cc1d2ca18 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -173,20 +173,7 @@ fn solution_from_chalk(
     db: &dyn HirDatabase,
     solution: chalk_solve::Solution<Interner>,
 ) -> Solution {
-    match solution {
-        chalk_solve::Solution::Unique(constr_subst) => {
-            Solution::Unique(from_chalk(db, constr_subst))
-        }
-        chalk_solve::Solution::Ambig(chalk_solve::Guidance::Definite(subst)) => {
-            Solution::Ambig(Guidance::Definite(from_chalk(db, subst)))
-        }
-        chalk_solve::Solution::Ambig(chalk_solve::Guidance::Suggested(subst)) => {
-            Solution::Ambig(Guidance::Suggested(from_chalk(db, subst)))
-        }
-        chalk_solve::Solution::Ambig(chalk_solve::Guidance::Unknown) => {
-            Solution::Ambig(Guidance::Unknown)
-        }
-    }
+    solution
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 701359e6f..c2e289660 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -21,159 +21,10 @@ use super::*;
 impl ToChalk for Ty {
     type Chalk = chalk_ir::Ty<Interner>;
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
-        match self.into_inner() {
-            TyKind::Ref(m, lt, ty) => {
-                chalk_ir::TyKind::Ref(m, lt, ty.to_chalk(db)).intern(&Interner)
-            }
-            TyKind::Array(ty, size) => {
-                chalk_ir::TyKind::Array(ty.to_chalk(db), size).intern(&Interner)
-            }
-            TyKind::Function(FnPointer { sig, substitution: substs, num_binders }) => {
-                let substitution = chalk_ir::FnSubst(substs.0.to_chalk(db));
-                chalk_ir::TyKind::Function(chalk_ir::FnPointer { num_binders, sig, substitution })
-                    .intern(&Interner)
-            }
-            TyKind::AssociatedType(assoc_type_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::AssociatedType(assoc_type_id, substitution).intern(&Interner)
-            }
-
-            TyKind::OpaqueType(id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::OpaqueType(id, substitution).intern(&Interner)
-            }
-
-            TyKind::Foreign(id) => chalk_ir::TyKind::Foreign(id).intern(&Interner),
-
-            TyKind::Scalar(scalar) => chalk_ir::TyKind::Scalar(scalar).intern(&Interner),
-
-            TyKind::Tuple(cardinality, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Tuple(cardinality, substitution).intern(&Interner)
-            }
-            TyKind::Raw(mutability, ty) => {
-                let ty = ty.to_chalk(db);
-                chalk_ir::TyKind::Raw(mutability, ty).intern(&Interner)
-            }
-            TyKind::Slice(ty) => chalk_ir::TyKind::Slice(ty.to_chalk(db)).intern(&Interner),
-            TyKind::Str => chalk_ir::TyKind::Str.intern(&Interner),
-            TyKind::FnDef(id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::FnDef(id, substitution).intern(&Interner)
-            }
-            TyKind::Never => chalk_ir::TyKind::Never.intern(&Interner),
-
-            TyKind::Closure(closure_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Closure(closure_id, substitution).intern(&Interner)
-            }
-
-            TyKind::Adt(adt_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Adt(adt_id, substitution).intern(&Interner)
-            }
-            TyKind::Alias(AliasTy::Projection(proj_ty)) => {
-                chalk_ir::AliasTy::Projection(proj_ty.to_chalk(db))
-                    .cast(&Interner)
-                    .intern(&Interner)
-            }
-            TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
-                chalk_ir::AliasTy::Opaque(opaque_ty.to_chalk(db)).cast(&Interner).intern(&Interner)
-            }
-            TyKind::Placeholder(idx) => idx.to_ty::<Interner>(&Interner),
-            TyKind::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
-            TyKind::InferenceVar(..) => panic!("uncanonicalized infer ty"),
-            TyKind::Dyn(dyn_ty) => {
-                let (bounds, binders) = dyn_ty.bounds.into_value_and_skipped_binders();
-                let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
-                    &Interner,
-                    bounds.interned().iter().cloned().map(|p| p.to_chalk(db)),
-                );
-                let bounded_ty = chalk_ir::DynTy {
-                    bounds: chalk_ir::Binders::new(binders, where_clauses),
-                    lifetime: dyn_ty.lifetime,
-                };
-                chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
-            }
-            TyKind::Error => chalk_ir::TyKind::Error.intern(&Interner),
-        }
+        self
     }
     fn from_chalk(db: &dyn HirDatabase, chalk: chalk_ir::Ty<Interner>) -> Self {
-        match chalk.data(&Interner).kind.clone() {
-            chalk_ir::TyKind::Error => TyKind::Error,
-            chalk_ir::TyKind::Array(ty, size) => TyKind::Array(from_chalk(db, ty), size),
-            chalk_ir::TyKind::Placeholder(idx) => TyKind::Placeholder(idx),
-            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => {
-                TyKind::Alias(AliasTy::Projection(from_chalk(db, proj)))
-            }
-            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
-                TyKind::Alias(AliasTy::Opaque(from_chalk(db, opaque_ty)))
-            }
-            chalk_ir::TyKind::Function(chalk_ir::FnPointer {
-                num_binders,
-                sig,
-                substitution,
-                ..
-            }) => {
-                assert_eq!(num_binders, 0);
-                let substs = crate::FnSubst(from_chalk(db, substitution.0));
-                TyKind::Function(FnPointer { num_binders, sig, substitution: substs })
-            }
-            chalk_ir::TyKind::BoundVar(idx) => TyKind::BoundVar(idx),
-            chalk_ir::TyKind::InferenceVar(_iv, _kind) => TyKind::Error,
-            chalk_ir::TyKind::Dyn(dyn_ty) => {
-                assert_eq!(dyn_ty.bounds.binders.len(&Interner), 1);
-                let (bounds, binders) = dyn_ty.bounds.into_value_and_skipped_binders();
-                let where_clauses = crate::QuantifiedWhereClauses::from_iter(
-                    &Interner,
-                    bounds.interned().iter().cloned().map(|p| from_chalk(db, p)),
-                );
-                TyKind::Dyn(crate::DynTy {
-                    bounds: crate::Binders::new(binders, where_clauses),
-                    // HACK: we sometimes get lifetime variables back in solutions
-                    // from Chalk, and don't have the infrastructure to substitute
-                    // them yet. So for now we just turn them into 'static right
-                    // when we get them
-                    lifetime: static_lifetime(),
-                })
-            }
-
-            chalk_ir::TyKind::Adt(adt_id, subst) => TyKind::Adt(adt_id, from_chalk(db, subst)),
-            chalk_ir::TyKind::AssociatedType(type_id, subst) => {
-                TyKind::AssociatedType(type_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::OpaqueType(opaque_type_id, subst) => {
-                TyKind::OpaqueType(opaque_type_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::Scalar(scalar) => TyKind::Scalar(scalar),
-            chalk_ir::TyKind::Tuple(cardinality, subst) => {
-                TyKind::Tuple(cardinality, from_chalk(db, subst))
-            }
-            chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)),
-            chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)),
-            chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
-                // HACK: we sometimes get lifetime variables back in solutions
-                // from Chalk, and don't have the infrastructure to substitute
-                // them yet. So for now we just turn them into 'static right
-                // when we get them
-                TyKind::Ref(mutability, static_lifetime(), from_chalk(db, ty))
-            }
-            chalk_ir::TyKind::Str => TyKind::Str,
-            chalk_ir::TyKind::Never => TyKind::Never,
-
-            chalk_ir::TyKind::FnDef(fn_def_id, subst) => {
-                TyKind::FnDef(fn_def_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::Closure(id, subst) => TyKind::Closure(id, from_chalk(db, subst)),
-
-            chalk_ir::TyKind::Foreign(foreign_def_id) => TyKind::Foreign(foreign_def_id),
-            chalk_ir::TyKind::Generator(_, _) => unimplemented!(), // FIXME
-            chalk_ir::TyKind::GeneratorWitness(_, _) => unimplemented!(), // FIXME
-        }
-        .intern(&Interner)
+        chalk
     }
 }
 
@@ -181,17 +32,11 @@ impl ToChalk for GenericArg {
     type Chalk = chalk_ir::GenericArg<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        match self.interned() {
-            crate::GenericArgData::Ty(ty) => ty.clone().to_chalk(db).cast(&Interner),
-        }
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        match chalk.interned() {
-            chalk_ir::GenericArgData::Ty(ty) => Ty::from_chalk(db, ty.clone()).cast(&Interner),
-            chalk_ir::GenericArgData::Lifetime(_) => unimplemented!(),
-            chalk_ir::GenericArgData::Const(_) => unimplemented!(),
-        }
+        chalk
     }
 }
 
@@ -199,18 +44,14 @@ impl ToChalk for Substitution {
     type Chalk = chalk_ir::Substitution<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Substitution<Interner> {
-        chalk_ir::Substitution::from_iter(
-            &Interner,
-            self.iter(&Interner).map(|ty| ty.clone().to_chalk(db)),
-        )
+        self
     }
 
     fn from_chalk(
         db: &dyn HirDatabase,
         parameters: chalk_ir::Substitution<Interner>,
     ) -> Substitution {
-        let tys = parameters.iter(&Interner).map(|p| from_chalk(db, p.clone())).collect();
-        Substitution::intern(tys)
+        parameters
     }
 }
 
@@ -218,15 +59,11 @@ impl ToChalk for TraitRef {
     type Chalk = chalk_ir::TraitRef<Interner>;
 
     fn to_chalk(self: TraitRef, db: &dyn HirDatabase) -> chalk_ir::TraitRef<Interner> {
-        let trait_id = self.trait_id;
-        let substitution = self.substitution.to_chalk(db);
-        chalk_ir::TraitRef { trait_id, substitution }
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, trait_ref: chalk_ir::TraitRef<Interner>) -> Self {
-        let trait_id = trait_ref.trait_id;
-        let substs = from_chalk(db, trait_ref.substitution);
-        TraitRef { trait_id, substitution: substs }
+        trait_ref
     }
 }
 
@@ -287,34 +124,14 @@ impl ToChalk for WhereClause {
     type Chalk = chalk_ir::WhereClause<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::WhereClause<Interner> {
-        match self {
-            WhereClause::Implemented(trait_ref) => {
-                chalk_ir::WhereClause::Implemented(trait_ref.to_chalk(db))
-            }
-            WhereClause::AliasEq(alias_eq) => chalk_ir::WhereClause::AliasEq(alias_eq.to_chalk(db)),
-        }
+        self
     }
 
     fn from_chalk(
         db: &dyn HirDatabase,
         where_clause: chalk_ir::WhereClause<Interner>,
     ) -> WhereClause {
-        match where_clause {
-            chalk_ir::WhereClause::Implemented(tr) => WhereClause::Implemented(from_chalk(db, tr)),
-            chalk_ir::WhereClause::AliasEq(alias_eq) => {
-                WhereClause::AliasEq(from_chalk(db, alias_eq))
-            }
-
-            chalk_ir::WhereClause::LifetimeOutlives(_) => {
-                // we shouldn't get these from Chalk
-                panic!("encountered LifetimeOutlives from Chalk")
-            }
-
-            chalk_ir::WhereClause::TypeOutlives(_) => {
-                // we shouldn't get these from Chalk
-                panic!("encountered TypeOutlives from Chalk")
-            }
-        }
+        where_clause
     }
 }
 
@@ -322,37 +139,25 @@ impl ToChalk for ProjectionTy {
     type Chalk = chalk_ir::ProjectionTy<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
-        chalk_ir::ProjectionTy {
-            associated_ty_id: self.associated_ty_id,
-            substitution: self.substitution.to_chalk(db),
-        }
+        self
     }
 
     fn from_chalk(
         db: &dyn HirDatabase,
         projection_ty: chalk_ir::ProjectionTy<Interner>,
     ) -> ProjectionTy {
-        ProjectionTy {
-            associated_ty_id: projection_ty.associated_ty_id,
-            substitution: from_chalk(db, projection_ty.substitution),
-        }
+        projection_ty
     }
 }
 impl ToChalk for OpaqueTy {
     type Chalk = chalk_ir::OpaqueTy<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        chalk_ir::OpaqueTy {
-            opaque_ty_id: self.opaque_ty_id,
-            substitution: self.substitution.to_chalk(db),
-        }
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        OpaqueTy {
-            opaque_ty_id: chalk.opaque_ty_id,
-            substitution: from_chalk(db, chalk.substitution),
-        }
+        chalk
     }
 }
 
@@ -360,21 +165,11 @@ impl ToChalk for AliasTy {
     type Chalk = chalk_ir::AliasTy<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        match self {
-            AliasTy::Projection(projection_ty) => {
-                chalk_ir::AliasTy::Projection(projection_ty.to_chalk(db))
-            }
-            AliasTy::Opaque(opaque_ty) => chalk_ir::AliasTy::Opaque(opaque_ty.to_chalk(db)),
-        }
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        match chalk {
-            chalk_ir::AliasTy::Projection(projection_ty) => {
-                AliasTy::Projection(from_chalk(db, projection_ty))
-            }
-            chalk_ir::AliasTy::Opaque(opaque_ty) => AliasTy::Opaque(from_chalk(db, opaque_ty)),
-        }
+        chalk
     }
 }
 
@@ -382,11 +177,11 @@ impl ToChalk for AliasEq {
     type Chalk = chalk_ir::AliasEq<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasEq<Interner> {
-        chalk_ir::AliasEq { alias: self.alias.to_chalk(db), ty: self.ty.to_chalk(db) }
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, alias_eq: chalk_ir::AliasEq<Interner>) -> Self {
-        AliasEq { alias: from_chalk(db, alias_eq.alias), ty: from_chalk(db, alias_eq.ty) }
+        alias_eq
     }
 }
 
@@ -394,68 +189,56 @@ impl ToChalk for DomainGoal {
     type Chalk = chalk_ir::DomainGoal<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::DomainGoal<Interner> {
-        match self {
-            DomainGoal::Holds(WhereClause::Implemented(tr)) => tr.to_chalk(db).cast(&Interner),
-            DomainGoal::Holds(WhereClause::AliasEq(alias_eq)) => {
-                alias_eq.to_chalk(db).cast(&Interner)
-            }
-        }
+        self
     }
 
-    fn from_chalk(_db: &dyn HirDatabase, _goal: chalk_ir::DomainGoal<Interner>) -> Self {
-        unimplemented!()
+    fn from_chalk(_db: &dyn HirDatabase, goal: chalk_ir::DomainGoal<Interner>) -> Self {
+        goal
     }
 }
 
 impl<T> ToChalk for Canonical<T>
 where
-    T: ToChalk,
-    T::Chalk: HasInterner<Interner = Interner>,
+    T: HasInterner<Interner = Interner>,
 {
-    type Chalk = chalk_ir::Canonical<T::Chalk>;
+    type Chalk = chalk_ir::Canonical<T>;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
-        let value = self.value.to_chalk(db);
-        chalk_ir::Canonical { value, binders: self.binders }
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T> {
+        self
     }
 
-    fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
-        Canonical { binders: canonical.binders, value: from_chalk(db, canonical.value) }
+    fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T>) -> Canonical<T> {
+        canonical
     }
 }
 
 impl<T: ToChalk> ToChalk for InEnvironment<T>
 where
-    T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
+    T: HasInterner<Interner = Interner>,
 {
-    type Chalk = chalk_ir::InEnvironment<T::Chalk>;
+    type Chalk = chalk_ir::InEnvironment<T>;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T::Chalk> {
-        chalk_ir::InEnvironment { environment: self.environment, goal: self.goal.to_chalk(db) }
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T> {
+        self
     }
 
-    fn from_chalk(
-        _db: &dyn HirDatabase,
-        _in_env: chalk_ir::InEnvironment<T::Chalk>,
-    ) -> InEnvironment<T> {
-        unimplemented!()
+    fn from_chalk(_db: &dyn HirDatabase, in_env: chalk_ir::InEnvironment<T>) -> InEnvironment<T> {
+        in_env
     }
 }
 
 impl<T: ToChalk> ToChalk for crate::Binders<T>
 where
-    T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
+    T: HasInterner<Interner = Interner>,
 {
-    type Chalk = chalk_ir::Binders<T::Chalk>;
+    type Chalk = chalk_ir::Binders<T>;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Binders<T::Chalk> {
-        let (value, binders) = self.into_value_and_skipped_binders();
-        chalk_ir::Binders::new(binders, value.to_chalk(db))
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Binders<T> {
+        self
     }
 
-    fn from_chalk(db: &dyn HirDatabase, binders: chalk_ir::Binders<T::Chalk>) -> crate::Binders<T> {
-        let (v, b) = binders.into_value_and_skipped_binders();
-        crate::Binders::new(b, from_chalk(db, v))
+    fn from_chalk(db: &dyn HirDatabase, binders: chalk_ir::Binders<T>) -> crate::Binders<T> {
+        binders
     }
 }
 
@@ -463,11 +246,11 @@ impl ToChalk for crate::ConstrainedSubst {
     type Chalk = chalk_ir::ConstrainedSubst<Interner>;
 
     fn to_chalk(self, _db: &dyn HirDatabase) -> Self::Chalk {
-        unimplemented!()
+        self
     }
 
     fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        ConstrainedSubst { subst: from_chalk(db, chalk.subst) }
+        chalk
     }
 }