1 files changed, 34 insertions, 18 deletions

diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index e0ca96c6d..e7c9dabc2 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -1,4 +1,6 @@
-//! FIXME: write short doc here
+//! The `HirDisplay` trait, which serves two purposes: Turning various bits from
+//! HIR back into source code, and just displaying them for debugging/testing
+//! purposes.
 
 use std::{
     array,
@@ -20,11 +22,11 @@ use hir_expand::name::Name;
 
 use crate::{
     const_from_placeholder_idx, db::HirDatabase, from_assoc_type_id, from_foreign_def_id,
-    from_placeholder_idx, lt_from_placeholder_idx, primitive, subst_prefix, to_assoc_type_id,
-    traits::chalk::from_chalk, utils::generics, AdtId, AliasEq, AliasTy, CallableDefId,
-    CallableSig, Const, ConstValue, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime,
-    LifetimeData, LifetimeOutlives, Mutability, OpaqueTy, ProjectionTy, ProjectionTyExt,
-    QuantifiedWhereClause, Scalar, TraitRef, TraitRefExt, Ty, TyExt, TyKind, WhereClause,
+    from_placeholder_idx, lt_from_placeholder_idx, mapping::from_chalk, primitive, subst_prefix,
+    to_assoc_type_id, utils::generics, AdtId, AliasEq, AliasTy, CallableDefId, CallableSig, Const,
+    ConstValue, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime, LifetimeData,
+    LifetimeOutlives, Mutability, OpaqueTy, ProjectionTy, ProjectionTyExt, QuantifiedWhereClause,
+    Scalar, TraitRef, TraitRefExt, Ty, TyExt, TyKind, WhereClause,
 };
 
 pub struct HirFormatter<'a> {
@@ -265,7 +267,7 @@ impl HirDisplay for ProjectionTy {
         write!(f, " as {}", trait_.name)?;
         if self.substitution.len(&Interner) > 1 {
             write!(f, "<")?;
-            f.write_joined(&self.substitution.interned()[1..], ", ")?;
+            f.write_joined(&self.substitution.as_slice(&Interner)[1..], ", ")?;
             write!(f, ">")?;
         }
         write!(f, ">::{}", f.db.type_alias_data(from_assoc_type_id(self.associated_ty_id)).name)?;
@@ -287,6 +289,8 @@ impl HirDisplay for GenericArg {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         match self.interned() {
             crate::GenericArgData::Ty(ty) => ty.hir_fmt(f),
+            crate::GenericArgData::Lifetime(lt) => lt.hir_fmt(f),
+            crate::GenericArgData::Const(c) => c.hir_fmt(f),
         }
     }
 }
@@ -414,7 +418,7 @@ impl HirDisplay for Ty {
                     write!(f, ",)")?;
                 } else {
                     write!(f, "(")?;
-                    f.write_joined(&*substs.interned(), ", ")?;
+                    f.write_joined(&*substs.as_slice(&Interner), ", ")?;
                     write!(f, ")")?;
                 }
             }
@@ -442,7 +446,7 @@ impl HirDisplay for Ty {
                     // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
                     if total_len > 0 {
                         write!(f, "<")?;
-                        f.write_joined(&parameters.interned()[..total_len], ", ")?;
+                        f.write_joined(&parameters.as_slice(&Interner)[..total_len], ", ")?;
                         write!(f, ">")?;
                     }
                 }
@@ -489,7 +493,7 @@ impl HirDisplay for Ty {
                             .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
                             .filter(|defaults| !defaults.is_empty())
                         {
-                            None => parameters.interned().as_ref(),
+                            None => parameters.as_slice(&Interner),
                             Some(default_parameters) => {
                                 let mut default_from = 0;
                                 for (i, parameter) in parameters.iter(&Interner).enumerate() {
@@ -513,11 +517,11 @@ impl HirDisplay for Ty {
                                         }
                                     }
                                 }
-                                &parameters.interned()[0..default_from]
+                                &parameters.as_slice(&Interner)[0..default_from]
                             }
                         }
                     } else {
-                        parameters.interned().as_ref()
+                        parameters.as_slice(&Interner)
                     };
                     if !parameters_to_write.is_empty() {
                         write!(f, "<")?;
@@ -540,7 +544,7 @@ impl HirDisplay for Ty {
                     write!(f, "{}::{}", trait_.name, type_alias_data.name)?;
                     if parameters.len(&Interner) > 0 {
                         write!(f, "<")?;
-                        f.write_joined(&*parameters.interned(), ", ")?;
+                        f.write_joined(&*parameters.as_slice(&Interner), ", ")?;
                         write!(f, ">")?;
                     }
                 } else {
@@ -664,6 +668,8 @@ impl HirDisplay for Ty {
                 write!(f, "{{unknown}}")?;
             }
             TyKind::InferenceVar(..) => write!(f, "_")?,
+            TyKind::Generator(..) => write!(f, "{{generator}}")?,
+            TyKind::GeneratorWitness(..) => write!(f, "{{generator witness}}")?,
         }
         Ok(())
     }
@@ -741,17 +747,17 @@ fn write_bounds_like_dyn_trait(
                 if !first {
                     write!(f, " + ")?;
                 }
-                // We assume that the self type is $0 (i.e. the
+                // We assume that the self type is ^0.0 (i.e. the
                 // existential) here, which is the only thing that's
                 // possible in actual Rust, and hence don't print it
                 write!(f, "{}", f.db.trait_data(trait_).name)?;
-                if let [_, params @ ..] = &*trait_ref.substitution.interned().as_slice() {
+                if let [_, params @ ..] = &*trait_ref.substitution.as_slice(&Interner) {
                     if is_fn_trait {
                         if let Some(args) =
                             params.first().and_then(|it| it.assert_ty_ref(&Interner).as_tuple())
                         {
                             write!(f, "(")?;
-                            f.write_joined(&*args.interned(), ", ")?;
+                            f.write_joined(args.as_slice(&Interner), ", ")?;
                             write!(f, ")")?;
                         }
                     } else if !params.is_empty() {
@@ -783,6 +789,10 @@ fn write_bounds_like_dyn_trait(
                 }
                 ty.hir_fmt(f)?;
             }
+
+            // FIXME implement these
+            WhereClause::LifetimeOutlives(_) => {}
+            WhereClause::TypeOutlives(_) => {}
         }
         first = false;
     }
@@ -806,7 +816,7 @@ fn fmt_trait_ref(tr: &TraitRef, f: &mut HirFormatter, use_as: bool) -> Result<()
     write!(f, "{}", f.db.trait_data(tr.hir_trait_id()).name)?;
     if tr.substitution.len(&Interner) > 1 {
         write!(f, "<")?;
-        f.write_joined(&tr.substitution.interned()[1..], ", ")?;
+        f.write_joined(&tr.substitution.as_slice(&Interner)[1..], ", ")?;
         write!(f, ">")?;
     }
     Ok(())
@@ -837,6 +847,10 @@ impl HirDisplay for WhereClause {
                 ty.hir_fmt(f)?;
             }
             WhereClause::AliasEq(_) => write!(f, "{{error}}")?,
+
+            // FIXME implement these
+            WhereClause::TypeOutlives(..) => {}
+            WhereClause::LifetimeOutlives(..) => {}
         }
         Ok(())
     }
@@ -881,9 +895,11 @@ impl HirDisplay for DomainGoal {
             DomainGoal::Holds(wc) => {
                 write!(f, "Holds(")?;
                 wc.hir_fmt(f)?;
-                write!(f, ")")
+                write!(f, ")")?;
             }
+            _ => write!(f, "?")?,
         }
+        Ok(())
     }
 }