Remove FlatType::Erroneous

crates/ast/src/solve_type.rs

@@ -1455,8 +1455,6 @@ fn adjust_rank_content(
 
                     rank
                 }
-
-                Erroneous(_) => group_rank,
             }
         }
 
@@ -1595,7 +1593,7 @@ fn instantiate_rigids_help(
                     }
                 }
 
-                EmptyRecord | EmptyTagUnion | Erroneous(_) => {}
+                EmptyRecord | EmptyTagUnion => {}
 
                 Record(fields, ext_var) => {
                     for index in fields.iter_variables() {
@@ -1775,7 +1773,7 @@ fn deep_copy_var_help(
                     Func(arg_vars, new_closure_var, new_ret_var)
                 }
 
-                same @ EmptyRecord | same @ EmptyTagUnion | same @ Erroneous(_) => same,
+                same @ EmptyRecord | same @ EmptyTagUnion => same,
 
                 Record(fields, ext_var) => {
                     let record_fields = {

crates/compiler/can/src/copy.rs

@@ -844,7 +844,7 @@ fn deep_copy_type_vars<C: CopyEnv>(
 
             // Everything else is a mechanical descent.
             Structure(flat_type) => match flat_type {
-                EmptyRecord | EmptyTagUnion | Erroneous(_) => Structure(flat_type),
+                EmptyRecord | EmptyTagUnion => Structure(flat_type),
                 Apply(symbol, arguments) => {
                     descend_slice!(arguments);
 

crates/compiler/can/src/exhaustive.rs

@@ -148,7 +148,6 @@ fn index_var(
                 FlatType::Func(_, _, _) | FlatType::FunctionOrTagUnion(_, _, _) => {
                     return Err(TypeError)
                 }
-                FlatType::Erroneous(_) => return Err(TypeError),
                 FlatType::Apply(Symbol::LIST_LIST, args) => {
                     match (subs.get_subs_slice(*args), ctor) {
                         ([elem_var], IndexCtor::List) => {

crates/compiler/derive_key/src/decoding.rs

@@ -72,7 +72,6 @@ impl FlatDecodable {
                     Err(Underivable) // yet
                 }
                 //
-                FlatType::Erroneous(_) => Err(Underivable),
                 FlatType::Func(..) => Err(Underivable),
             },
             Content::Alias(sym, _, real_var, _) => match sym {

crates/compiler/derive_key/src/encoding.rs

@@ -106,7 +106,6 @@ impl FlatEncodable {
                 FlatType::EmptyRecord => Ok(Key(FlatEncodableKey::Record(vec![]))),
                 FlatType::EmptyTagUnion => Ok(Key(FlatEncodableKey::TagUnion(vec![]))),
                 //
-                FlatType::Erroneous(_) => Err(Underivable),
                 FlatType::Func(..) => Err(Underivable),
             },
             Content::Alias(sym, _, real_var, _) => match sym {

crates/compiler/derive_key/src/hash.rs

@@ -103,7 +103,6 @@ impl FlatHash {
                 FlatType::EmptyRecord => Ok(Key(FlatHashKey::Record(vec![]))),
                 FlatType::EmptyTagUnion => Ok(Key(FlatHashKey::TagUnion(vec![]))),
                 //
-                FlatType::Erroneous(_) => Err(Underivable),
                 FlatType::Func(..) => Err(Underivable),
             },
             Content::Alias(sym, _, real_var, _) => match sym {

crates/compiler/mono/src/layout.rs

@@ -1979,7 +1979,7 @@ fn lambda_set_size(subs: &Subs, var: Variable) -> (usize, usize, usize) {
                     }
                     stack.push((*ext, depth_any + 1, depth_lset));
                 }
-                FlatType::Erroneous(_) | FlatType::EmptyRecord | FlatType::EmptyTagUnion => {}
+                FlatType::EmptyRecord | FlatType::EmptyTagUnion => {}
             },
             Content::FlexVar(_)
             | Content::RigidVar(_)
@@ -3188,7 +3188,6 @@ fn layout_from_flat_type<'a>(
             layout_from_recursive_union(env, rec_var, &tags)
         }
         EmptyTagUnion => cacheable(Ok(Layout::VOID)),
-        Erroneous(_) => cacheable(Err(LayoutProblem::Erroneous)),
         EmptyRecord => cacheable(Ok(Layout::UNIT)),
     }
 }

crates/compiler/mono/src/layout_soa.rs

@@ -189,8 +189,6 @@ impl FunctionLayout {
                 })
             }
 
-            FlatType::Erroneous(_) => Err(TypeError(())),
-
             _ => todo!(),
         }
     }
@@ -867,7 +865,6 @@ impl Layout {
 
                 Ok(Layout::UnionRecursive(slices))
             }
-            FlatType::Erroneous(_) => Err(TypeError(())),
             FlatType::EmptyRecord => Ok(Layout::UNIT),
             FlatType::EmptyTagUnion => Ok(Layout::VOID),
         }

crates/compiler/solve/src/ability.rs

@@ -715,13 +715,6 @@ trait DerivableVisitor {
                     }
                     EmptyRecord => Self::visit_empty_record(var)?,
                     EmptyTagUnion => Self::visit_empty_tag_union(var)?,
-
-                    Erroneous(_) => {
-                        return Err(NotDerivable {
-                            var,
-                            context: NotDerivableContext::NoContext,
-                        })
-                    }
                 },
                 Alias(
                     Symbol::NUM_NUM | Symbol::NUM_INTEGER | Symbol::NUM_FLOATINGPOINT,

crates/compiler/solve/src/solve.rs

@@ -1490,13 +1490,7 @@ fn solve(
                 let branches_content = subs.get_content_without_compacting(branches_var);
                 let already_have_error = matches!(
                     (real_content, branches_content),
-                    (
+                    (Content::Error, _) | (_, Content::Error)
-                        Content::Error | Content::Structure(FlatType::Erroneous(_)),
-                        _
-                    ) | (
-                        _,
-                        Content::Error | Content::Structure(FlatType::Erroneous(_))
-                    )
                 );
 
                 let snapshot = subs.snapshot();
@@ -3826,8 +3820,6 @@ fn adjust_rank_content(
 
                     rank
                 }
-
-                Erroneous(_) => group_rank,
             }
         }
 
@@ -4076,7 +4068,7 @@ fn deep_copy_var_help(
                         Func(new_arguments, new_closure_var, new_ret_var)
                     }
 
-                    same @ EmptyRecord | same @ EmptyTagUnion | same @ Erroneous(_) => same,
+                    same @ EmptyRecord | same @ EmptyTagUnion => same,
 
                     Record(fields, ext_var) => {
                         let record_fields = {

crates/compiler/types/src/pretty_print.rs

@@ -408,7 +408,7 @@ fn find_names_needed(
                 find_under_alias,
             );
         }
-        Error | Structure(Erroneous(_)) | Structure(EmptyRecord) | Structure(EmptyTagUnion) => {
+        Error | Structure(EmptyRecord) | Structure(EmptyTagUnion) => {
             // Errors and empty records don't need names.
         }
     }
@@ -1284,7 +1284,6 @@ fn write_flat_type<'a>(
                 )
             })
         }
-        Erroneous(problem) => write!(buf, "<Type Mismatch: {:?}>", problem).unwrap(),
     }
 }
 

crates/compiler/types/src/subs.rs

@@ -975,7 +975,6 @@ fn subs_fmt_flat_type(this: &FlatType, subs: &Subs, f: &mut fmt::Formatter) -> f
 
             write!(f, "]<{:?}> as <{:?}>", new_ext, rec)
         }
-        FlatType::Erroneous(e) => write!(f, "Erroneous({:?})", e),
         FlatType::EmptyRecord => write!(f, "EmptyRecord"),
         FlatType::EmptyTagUnion => write!(f, "EmptyTagUnion"),
     }
@@ -2517,7 +2516,6 @@ pub enum FlatType {
     FunctionOrTagUnion(SubsSlice<TagName>, SubsSlice<Symbol>, Variable),
 
     RecursiveTagUnion(Variable, UnionTags, Variable),
-    Erroneous(SubsIndex<Problem>),
     EmptyRecord,
     EmptyTagUnion,
 }
@@ -3274,7 +3272,7 @@ fn occurs(
 
                         short_circuit_help(subs, root_var, &new_seen, *ext_var)
                     }
-                    EmptyRecord | EmptyTagUnion | Erroneous(_) => Ok(()),
+                    EmptyRecord | EmptyTagUnion => Ok(()),
                 }
             }
             Alias(_, args, _, _) => {
@@ -3445,7 +3443,7 @@ fn explicit_substitute(
                         subs.set_content(in_var, Structure(Record(vars_by_field, new_ext_var)));
                     }
 
-                    EmptyRecord | EmptyTagUnion | Erroneous(_) => {}
+                    EmptyRecord | EmptyTagUnion => {}
                 }
 
                 in_var
@@ -3628,9 +3626,7 @@ fn get_var_names(
                     accum
                 }
 
-                FlatType::EmptyRecord | FlatType::EmptyTagUnion | FlatType::Erroneous(_) => {
+                FlatType::EmptyRecord | FlatType::EmptyTagUnion => taken_names,
-                    taken_names
-                }
 
                 FlatType::Record(vars_by_field, ext_var) => {
                     let mut accum = get_var_names(subs, ext_var, taken_names);
@@ -4039,8 +4035,6 @@ fn flat_type_to_err_type(
                     panic!("Tried to convert a recursive tag union extension to an error, but the tag union extension had the ErrorType of {:?}", other)
             }
         }
-
-        Erroneous(_) => ErrorType::Error,
     }
 }
 
@@ -4320,9 +4314,6 @@ impl StorageSubs {
                 Self::offset_tag_union(offsets, *union_tags),
                 Self::offset_variable(offsets, *ext),
             ),
-            FlatType::Erroneous(problem) => {
-                FlatType::Erroneous(Self::offset_problem(offsets, *problem))
-            }
             FlatType::EmptyRecord => FlatType::EmptyRecord,
             FlatType::EmptyTagUnion => FlatType::EmptyTagUnion,
         }
@@ -4606,7 +4597,7 @@ fn storage_copy_var_to_help(env: &mut StorageCopyVarToEnv<'_>, var: Variable) ->
                     Func(new_arguments, new_closure_var, new_ret_var)
                 }
 
-                same @ EmptyRecord | same @ EmptyTagUnion | same @ Erroneous(_) => same,
+                same @ EmptyRecord | same @ EmptyTagUnion => same,
 
                 Record(fields, ext_var) => {
                     let record_fields = {
@@ -5024,13 +5015,6 @@ fn copy_import_to_help(env: &mut CopyImportEnv<'_>, max_rank: Rank, var: Variabl
     // We have already marked the variable as copied, so we
     // will not repeat this work or crawl this variable again.
     match desc.content {
-        Structure(Erroneous(_)) => {
-            // Make this into a flex var so that we don't have to copy problems across module
-            // boundaries - the error will be reported locally.
-            env.target.set(copy, make_descriptor(FlexVar(None)));
-
-            copy
-        }
         Structure(flat_type) => {
             let new_flat_type = match flat_type {
                 Apply(symbol, arguments) => {
@@ -5061,8 +5045,6 @@ fn copy_import_to_help(env: &mut CopyImportEnv<'_>, max_rank: Rank, var: Variabl
                     Func(new_arguments, new_closure_var, new_ret_var)
                 }
 
-                Erroneous(_) => internal_error!("I thought this was handled above"),
-
                 same @ EmptyRecord | same @ EmptyTagUnion => same,
 
                 Record(fields, ext_var) => {
@@ -5435,8 +5417,6 @@ fn instantiate_rigids_help(subs: &mut Subs, max_rank: Rank, initial: Variable) {
                     stack.push(ext_var);
                     stack.push(rec_var);
                 }
-
-                Erroneous(_) => (),
             },
             Alias(_, args, var, _) => {
                 let var = *var;
@@ -5539,7 +5519,7 @@ pub fn get_member_lambda_sets_at_region(subs: &Subs, var: Variable, target_regio
                     );
                     stack.push(*ext);
                 }
-                FlatType::Erroneous(_) | FlatType::EmptyRecord | FlatType::EmptyTagUnion => {}
+                FlatType::EmptyRecord | FlatType::EmptyTagUnion => {}
             },
             Content::Alias(_, _, real_var, _) => {
                 stack.push(*real_var);
@@ -5606,7 +5586,6 @@ fn is_inhabited(subs: &Subs, var: Variable) -> bool {
                     }
                 }
                 FlatType::FunctionOrTagUnion(_, _, _) => {}
-                FlatType::Erroneous(_) => {}
                 FlatType::EmptyRecord => {}
                 FlatType::EmptyTagUnion => {
                     return false;

crates/glue/src/types.rs

@@ -866,7 +866,6 @@ fn add_type_help<'a>(
         Content::Structure(FlatType::FunctionOrTagUnion(_, _, _)) => {
             todo!()
         }
-        Content::Structure(FlatType::Erroneous(_)) => todo!(),
         Content::Structure(FlatType::EmptyRecord) => {
             types.add_anonymous(&env.layout_cache.interner, RocType::Unit, layout)
         }