Remove problem storage in Type::Erroneous

crates/ast/src/lang/core/types.rs

@@ -744,7 +744,7 @@ fn to_type_apply<'a>(
             Err(problem) => {
                 env.problem(roc_problem::can::Problem::RuntimeError(problem));
 
-                return TypeApply::Erroneous(Problem::UnrecognizedIdent(ident.into()));
+                return TypeApply::Erroneous(Problem::CanonicalizationProblem);
             }
         }
     } else {
@@ -755,7 +755,7 @@ fn to_type_apply<'a>(
                 // it was imported but it doesn't expose this ident.
                 env.problem(roc_problem::can::Problem::RuntimeError(problem));
 
-                return TypeApply::Erroneous(Problem::UnrecognizedIdent((*ident).into()));
+                return TypeApply::Erroneous(Problem::CanonicalizationProblem);
             }
         }
     };

crates/compiler/can/src/annotation.rs

@@ -391,8 +391,7 @@ pub(crate) fn make_apply_symbol(
             Err(problem) => {
                 env.problem(roc_problem::can::Problem::RuntimeError(problem));
 
-                let ident: Ident = (*ident).into();
+                Err(Type::Erroneous)
-                Err(Type::Erroneous(Problem::UnrecognizedIdent(ident)))
             }
         }
     } else {
@@ -405,7 +404,7 @@ pub(crate) fn make_apply_symbol(
 
                 // A failed import should have already been reported through
                 // roc_can::env::Env::qualified_lookup's checks
-                Err(Type::Erroneous(Problem::SolvedTypeError))
+                Err(Type::Erroneous)
             }
         }
     }
@@ -626,14 +625,16 @@ fn can_annotation_help(
                     // use a known alias
 
                     if alias.type_variables.len() != args.len() {
-                        let error = Type::Erroneous(Problem::BadTypeArguments {
+                        env.problem(roc_problem::can::Problem::BadType(
+                            Problem::BadTypeArguments {
                                 symbol,
                                 region,
                                 alias_needs: alias.type_variables.len() as u8,
                                 type_got: args.len() as u8,
                                 alias_kind: alias.kind,
-                        });
+                            },
-                        return error;
+                        ));
+                        return Type::Erroneous;
                     }
 
                     let mut type_var_to_arg = Vec::new();
@@ -717,15 +718,13 @@ fn can_annotation_help(
                 Ok(symbol) => symbol,
 
                 Err((shadowed_symbol, shadow, _new_symbol)) => {
-                    let problem = Problem::Shadowed(shadowed_symbol.region, shadow.clone());
-
                     env.problem(roc_problem::can::Problem::Shadowing {
                         original_region: shadowed_symbol.region,
                         shadow,
                         kind: ShadowKind::Variable,
                     });
 
-                    return Type::Erroneous(problem);
+                    return Type::Erroneous;
                 }
             };
 
@@ -992,7 +991,7 @@ fn can_annotation_help(
                 region: Region::across_all(clauses.iter().map(|clause| &clause.region)),
             });
 
-            Type::Erroneous(Problem::CanonicalizationProblem)
+            Type::Erroneous
         }
         Malformed(string) => {
             malformed(env, region, string);
@@ -1044,13 +1043,13 @@ fn canonicalize_has_clause(
                 && !scope.abilities_store.is_ability(symbol)
                 {
                     env.problem(roc_problem::can::Problem::HasClauseIsNotAbility { region });
-                    return Err(Type::Erroneous(Problem::HasClauseIsNotAbility(region)));
+                    return Err(Type::Erroneous);
                 }
                 symbol
             }
             _ => {
                 env.problem(roc_problem::can::Problem::HasClauseIsNotAbility { region });
-                return Err(Type::Erroneous(Problem::HasClauseIsNotAbility(region)));
+                return Err(Type::Erroneous);
             }
         };
 
@@ -1070,10 +1069,7 @@ fn canonicalize_has_clause(
             shadow: shadow.clone(),
             kind: ShadowKind::Variable,
         });
-        return Err(Type::Erroneous(Problem::Shadowed(
+        return Err(Type::Erroneous);
-            shadowing.first_seen(),
-            shadow,
-        )));
     }
 
     let var = var_store.fresh();
@@ -1099,13 +1095,13 @@ fn can_extension_type<'a>(
         // Include erroneous types so that we don't overreport errors.
         matches!(
             typ,
-            Type::EmptyRec | Type::Record(..) | Type::Variable(..) | Type::Erroneous(..)
+            Type::EmptyRec | Type::Record(..) | Type::Variable(..) | Type::Erroneous
         )
     }
     fn valid_tag_ext_type(typ: &Type) -> bool {
         matches!(
             typ,
-            Type::EmptyTagUnion | Type::TagUnion(..) | Type::Variable(..) | Type::Erroneous(..)
+            Type::EmptyTagUnion | Type::TagUnion(..) | Type::Variable(..) | Type::Erroneous
         )
     }
 

crates/compiler/can/src/def.rs

@@ -2819,6 +2819,7 @@ fn correct_mutual_recursive_type_alias<'a>(
             alias_type.instantiate_aliases(
                 alias_region,
                 &can_instantiate_symbol,
+                &mut |problem| env.problems.push(Problem::BadType(problem)),
                 var_store,
                 &mut new_lambda_sets,
                 &mut new_infer_ext_vars,
@@ -3109,8 +3110,7 @@ fn mark_cyclic_alias<'a>(
     others: Vec<Symbol>,
     report: bool,
 ) {
-    let problem = roc_types::types::Problem::CyclicAlias(symbol, region, others.clone());
+    *typ = Type::Erroneous;
-    *typ = Type::Erroneous(problem);
 
     if report {
         let problem = Problem::CyclicAlias(symbol, region, others, alias_kind);

crates/compiler/problem/src/can.rs

@@ -188,6 +188,7 @@ pub enum Problem {
     MultipleListRestPattern {
         region: Region,
     },
+    BadType(roc_types::types::Problem),
 }
 
 impl Problem {
@@ -330,6 +331,7 @@ impl Problem {
             | Problem::RuntimeError(RuntimeError::ExposedButNotDefined(_))
             | Problem::RuntimeError(RuntimeError::NoImplementationNamed { .. })
             | Problem::ExposedButNotDefined(_) => None,
+            Problem::BadType(..) => None,
         }
     }
 }

crates/compiler/solve/src/solve.rs

@@ -2980,11 +2980,7 @@ fn type_to_variable<'a>(
                 result
             }
             Erroneous => {
-                // TODO: remove `Erroneous`, `Error` can always be used, and type problems known at
+                let content = Content::Error;
-                // this point can be reported during canonicalization.
-                let problem_index =
-                    SubsIndex::push_new(&mut subs.problems, types.get_problem(&typ).clone());
-                let content = Content::Structure(FlatType::Erroneous(problem_index));
 
                 register_with_known_var(subs, destination, rank, pools, content)
             }

crates/compiler/types/src/subs.rs

@@ -21,7 +21,7 @@ roc_error_macros::assert_sizeof_all!(FlatType, 3 * 8);
 roc_error_macros::assert_sizeof_all!(UnionTags, 12);
 roc_error_macros::assert_sizeof_all!(RecordFields, 2 * 8);
 
-roc_error_macros::assert_sizeof_aarch64!(Problem, 6 * 8);
+roc_error_macros::assert_sizeof_aarch64!(Problem, 5 * 8);
 roc_error_macros::assert_sizeof_wasm!(Problem, 32);
 roc_error_macros::assert_sizeof_default!(Problem, 6 * 8);
 
@@ -4040,12 +4040,7 @@ fn flat_type_to_err_type(
             }
         }
 
-        Erroneous(problem_index) => {
+        Erroneous(_) => ErrorType::Error,
-            let problem = subs.problems[problem_index.index as usize].clone();
-            state.problems.push(problem);
-
-            ErrorType::Error
-        }
     }
 }
 

crates/compiler/types/src/types.rs

@@ -173,6 +173,7 @@ impl RecordField<Type> {
         &mut self,
         region: Region,
         aliases: &'a F,
+        push_problem: &mut impl FnMut(Problem),
         var_store: &mut VarStore,
         new_lambda_sets: &mut ImSet<Variable>,
         new_infer_ext_vars: &mut ImSet<Variable>,
@@ -182,6 +183,7 @@ impl RecordField<Type> {
         self.as_inner_mut().instantiate_aliases(
             region,
             aliases,
+            push_problem,
             var_store,
             new_lambda_sets,
             new_infer_ext_vars,
@@ -228,6 +230,7 @@ impl LambdaSet {
         &mut self,
         region: Region,
         aliases: &'a F,
+        push_problem: &mut impl FnMut(Problem),
         var_store: &mut VarStore,
         new_lambda_sets: &mut ImSet<Variable>,
         new_infer_ext_vars: &mut ImSet<Variable>,
@@ -237,6 +240,7 @@ impl LambdaSet {
         self.0.instantiate_aliases(
             region,
             aliases,
+            push_problem,
             var_store,
             new_lambda_sets,
             new_infer_ext_vars,
@@ -1332,7 +1336,7 @@ pub enum Type {
     Variable(Variable),
     RangedNumber(NumericRange),
     /// A type error, which will code gen to a runtime error
-    Erroneous(Problem),
+    Erroneous,
 }
 
 /// A lambda set under an arrow in a ability member signature. For example, in
@@ -1428,7 +1432,7 @@ impl Clone for Type {
             Self::Apply(arg0, arg1, arg2) => Self::Apply(*arg0, arg1.clone(), *arg2),
             Self::Variable(arg0) => Self::Variable(*arg0),
             Self::RangedNumber(arg1) => Self::RangedNumber(*arg1),
-            Self::Erroneous(arg0) => Self::Erroneous(arg0.clone()),
+            Self::Erroneous => Self::Erroneous,
         }
     }
 }
@@ -1544,13 +1548,7 @@ impl fmt::Debug for Type {
 
                 write!(f, ")")
             }
-            Type::Erroneous(problem) => {
+            Type::Erroneous => write!(f, "Erroneous"),
-                write!(f, "Erroneous(")?;
-
-                problem.fmt(f)?;
-
-                write!(f, ")")
-            }
             Type::DelayedAlias(AliasCommon {
                 symbol,
                 type_arguments,
@@ -1910,7 +1908,7 @@ impl Type {
                     );
                 }
 
-                EmptyRec | EmptyTagUnion | Erroneous(_) => {}
+                EmptyRec | EmptyTagUnion | Erroneous => {}
             }
         }
     }
@@ -2040,7 +2038,7 @@ impl Type {
                     );
                 }
 
-                EmptyRec | EmptyTagUnion | Erroneous(_) => {}
+                EmptyRec | EmptyTagUnion | Erroneous => {}
             }
         }
     }
@@ -2143,7 +2141,7 @@ impl Type {
             }
             RangedNumber(_) => Ok(()),
             UnspecializedLambdaSet { .. } => Ok(()),
-            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous(_) | Variable(_) => Ok(()),
+            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous | Variable(_) => Ok(()),
         }
     }
 
@@ -2205,7 +2203,7 @@ impl Type {
             UnspecializedLambdaSet {
                 unspecialized: Uls(_, sym, _),
             } => *sym == rep_symbol,
-            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous(_) | Variable(_) => false,
+            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous | Variable(_) => false,
         }
     }
 
@@ -2261,7 +2259,7 @@ impl Type {
                 .iter()
                 .any(|arg| arg.value.contains_variable(rep_variable)),
             RangedNumber(_) => false,
-            EmptyRec | EmptyTagUnion | Erroneous(_) => false,
+            EmptyRec | EmptyTagUnion | Erroneous => false,
         }
     }
 
@@ -2295,6 +2293,7 @@ impl Type {
         &mut self,
         region: Region,
         aliases: &'a F,
+        push_problem: &mut impl FnMut(Problem),
         var_store: &mut VarStore,
         new_lambda_set_variables: &mut ImSet<Variable>,
         new_infer_ext_vars: &mut ImSet<Variable>,
@@ -2309,6 +2308,7 @@ impl Type {
                     arg.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2317,6 +2317,7 @@ impl Type {
                 closure.instantiate_aliases(
                     region,
                     aliases,
+                    push_problem,
                     var_store,
                     new_lambda_set_variables,
                     new_infer_ext_vars,
@@ -2324,6 +2325,7 @@ impl Type {
                 ret.instantiate_aliases(
                     region,
                     aliases,
+                    push_problem,
                     var_store,
                     new_lambda_set_variables,
                     new_infer_ext_vars,
@@ -2334,6 +2336,7 @@ impl Type {
                     ext.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2346,6 +2349,7 @@ impl Type {
                         x.instantiate_aliases(
                             region,
                             aliases,
+                            push_problem,
                             var_store,
                             new_lambda_set_variables,
                             new_infer_ext_vars,
@@ -2357,6 +2361,7 @@ impl Type {
                     ext.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2368,6 +2373,7 @@ impl Type {
                     x.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2378,6 +2384,7 @@ impl Type {
                     ext.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2400,6 +2407,7 @@ impl Type {
                     t.value.typ.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2416,6 +2424,7 @@ impl Type {
                     arg.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2426,6 +2435,7 @@ impl Type {
                     arg.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2435,6 +2445,7 @@ impl Type {
                 actual_type.instantiate_aliases(
                     region,
                     aliases,
+                    push_problem,
                     var_store,
                     new_lambda_set_variables,
                     new_infer_ext_vars,
@@ -2450,6 +2461,7 @@ impl Type {
                     arg.typ.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2460,6 +2472,7 @@ impl Type {
                     arg.instantiate_aliases(
                         region,
                         aliases,
+                        push_problem,
                         var_store,
                         new_lambda_set_variables,
                         new_infer_ext_vars,
@@ -2469,6 +2482,7 @@ impl Type {
                 actual_type.instantiate_aliases(
                     region,
                     aliases,
+                    push_problem,
                     var_store,
                     new_lambda_set_variables,
                     new_infer_ext_vars,
@@ -2522,13 +2536,14 @@ impl Type {
                         *self = alias;
                     } else {
                         if args.len() != alias.type_variables.len() {
-                            *self = Type::Erroneous(Problem::BadTypeArguments {
+                            push_problem(Problem::BadTypeArguments {
                                 symbol: *symbol,
                                 region,
                                 type_got: args.len() as u8,
                                 alias_needs: alias.type_variables.len() as u8,
                                 alias_kind: AliasKind::Structural,
                             });
+                            *self = Type::Erroneous;
                             return;
                         }
 
@@ -2555,6 +2570,7 @@ impl Type {
                             filler.value.instantiate_aliases(
                                 region,
                                 aliases,
+                                push_problem,
                                 var_store,
                                 new_lambda_set_variables,
                                 new_infer_ext_vars,
@@ -2591,6 +2607,7 @@ impl Type {
                         actual.instantiate_aliases(
                             region,
                             aliases,
+                            push_problem,
                             var_store,
                             new_lambda_set_variables,
                             new_infer_ext_vars,
@@ -2631,6 +2648,7 @@ impl Type {
                         x.value.instantiate_aliases(
                             region,
                             aliases,
+                            push_problem,
                             var_store,
                             new_lambda_set_variables,
                             new_infer_ext_vars,
@@ -2640,7 +2658,7 @@ impl Type {
             }
             RangedNumber(_) => {}
             UnspecializedLambdaSet { .. } => {}
-            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous(_) | Variable(_) => {}
+            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous | Variable(_) => {}
         }
     }
 
@@ -2770,16 +2788,13 @@ fn symbols_help(initial: &Type) -> Vec<Symbol> {
                 output.push(*symbol);
                 stack.extend(args.iter().map(|t| &t.value));
             }
-            Erroneous(Problem::CyclicAlias(alias, _, _)) => {
-                output.push(*alias);
-            }
             RangedNumber(_) => {}
             UnspecializedLambdaSet {
                 unspecialized: Uls(_, _sym, _),
             } => {
                 // ignore the member symbol because unspecialized lambda sets are internal-only
             }
-            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous(_) | Variable(_) => {}
+            EmptyRec | EmptyTagUnion | ClosureTag { .. } | Erroneous | Variable(_) => {}
         }
     }
 
@@ -2793,7 +2808,7 @@ fn variables_help(tipe: &Type, accum: &mut ImSet<Variable>) {
     use Type::*;
 
     match tipe {
-        EmptyRec | EmptyTagUnion | Erroneous(_) => (),
+        EmptyRec | EmptyTagUnion | Erroneous => (),
 
         Variable(v) => {
             accum.insert(*v);
@@ -2923,7 +2938,7 @@ fn variables_help_detailed(tipe: &Type, accum: &mut VariableDetail) {
     use Type::*;
 
     match tipe {
-        EmptyRec | EmptyTagUnion | Erroneous(_) => (),
+        EmptyRec | EmptyTagUnion | Erroneous => (),
 
         Variable(v) => {
             accum.type_variables.insert(*v);
@@ -3319,8 +3334,6 @@ impl Alias {
 pub enum Problem {
     CanonicalizationProblem,
     CircularType(Symbol, Box<ErrorType>, Region),
-    CyclicAlias(Symbol, Region, Vec<Symbol>),
-    UnrecognizedIdent(Ident),
     Shadowed(Region, Loc<Ident>),
     BadTypeArguments {
         symbol: Symbol,
@@ -3330,7 +3343,6 @@ pub enum Problem {
         alias_kind: AliasKind,
     },
     InvalidModule,
-    SolvedTypeError,
     HasClauseIsNotAbility(Region),
 }
 
@@ -4151,7 +4163,7 @@ fn instantiate_lambda_sets_as_unspecialized(
             }
             Type::Variable(_) => {}
             Type::RangedNumber(_) => {}
-            Type::Erroneous(_) => {}
+            Type::Erroneous => {}
         }
     }
 }

crates/reporting/src/error/canonicalize.rs

@@ -1037,6 +1037,54 @@ pub fn can_problem<'b>(
             title = "MULTIPLE LIST REST PATTERNS".to_string();
             severity = Severity::RuntimeError;
         }
+        Problem::BadType(type_problem) => {
+            use roc_types::types::Problem::*;
+            match type_problem {
+                BadTypeArguments {
+                    symbol,
+                    region,
+                    type_got,
+                    alias_needs,
+                    alias_kind,
+                } => {
+                    let needed_arguments = if alias_needs == 1 {
+                        alloc.reflow("1 type argument")
+                    } else {
+                        alloc
+                            .text(alias_needs.to_string())
+                            .append(alloc.reflow(" type arguments"))
+                    };
+
+                    let found_arguments = alloc.text(type_got.to_string());
+
+                    doc = alloc.stack([
+                        alloc.concat([
+                            alloc.reflow("The "),
+                            alloc.symbol_unqualified(symbol),
+                            alloc.reflow(" "),
+                            alloc.reflow(alias_kind.as_str()),
+                            alloc.reflow(" expects "),
+                            needed_arguments,
+                            alloc.reflow(", but it got "),
+                            found_arguments,
+                            alloc.reflow(" instead:"),
+                        ]),
+                        alloc.region(lines.convert_region(region)),
+                        alloc.reflow("Are there missing parentheses?"),
+                    ]);
+
+                    title = if type_got > alias_needs {
+                        "TOO MANY TYPE ARGUMENTS".to_string()
+                    } else {
+                        "TOO FEW TYPE ARGUMENTS".to_string()
+                    };
+
+                    severity = Severity::RuntimeError;
+                }
+
+                other => panic!("unhandled bad type: {:?}", other),
+            }
+        }
     };
 
     Report {

crates/reporting/src/error/type.rs

@@ -126,12 +126,6 @@ pub fn type_problem<'b>(
                     report(title, doc, filename)
                 }
 
-                SolvedTypeError => None, // Don't re-report cascading errors - see https://github.com/roc-lang/roc/pull/1711
-
-                // We'll also report these as a canonicalization problem, no need to re-report them.
-                CyclicAlias(..) => None,
-                UnrecognizedIdent(..) => None,
-
                 other => panic!("unhandled bad type: {:?}", other),
             }
         }