Use restricted Damerau-Levenshtein distance for diagnostics

compiler/rustc_ast_lowering/src/item.rs

@@ -13,7 +13,7 @@ use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
 use rustc_hir::PredicateOrigin;
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::ty::{DefIdTree, ResolverAstLowering, TyCtxt};
-use rustc_span::lev_distance::find_best_match_for_name;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::source_map::DesugaringKind;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{Span, Symbol};

compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -6,7 +6,7 @@ use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty;
 use rustc_session::parse::feature_err;
-use rustc_span::lev_distance::find_best_match_for_name;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::{Span, Symbol, DUMMY_SP};
 

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -34,8 +34,8 @@ use rustc_middle::ty::DynKind;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::{self, Const, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeVisitable};
 use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECTS};
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, Ident, Symbol};
 use rustc_span::{sym, Span, DUMMY_SP};
 use rustc_target::spec::abi;

compiler/rustc_hir_typeck/src/expr.rs

@@ -45,8 +45,8 @@ use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AdtKind, Ty, TypeVisitable};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_session::parse::feature_err;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::DesugaringKind;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::{Span, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_target::spec::abi::Abi::RustIntrinsic;

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -25,8 +25,8 @@ use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_session::lint;
 use rustc_span::def_id::DefId;
 use rustc_span::def_id::LocalDefId;
-use rustc_span::lev_distance::{
-    find_best_match_for_name_with_substrings, lev_distance_with_substrings,
+use rustc_span::edit_distance::{
+    edit_distance_with_substrings, find_best_match_for_name_with_substrings,
 };
 use rustc_span::symbol::sym;
 use rustc_span::{symbol::Ident, Span, Symbol, DUMMY_SP};
@@ -70,7 +70,7 @@ struct ProbeContext<'a, 'tcx> {
     impl_dups: FxHashSet<DefId>,
 
     /// When probing for names, include names that are close to the
-    /// requested name (by Levenshtein distance)
+    /// requested name (by edit distance)
     allow_similar_names: bool,
 
     /// Some(candidate) if there is a private candidate
@@ -1794,7 +1794,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
     /// Similarly to `probe_for_return_type`, this method attempts to find the best matching
     /// candidate method where the method name may have been misspelled. Similarly to other
-    /// Levenshtein based suggestions, we provide at most one such suggestion.
+    /// edit distance based suggestions, we provide at most one such suggestion.
     fn probe_for_similar_candidate(&mut self) -> Result<Option<ty::AssocItem>, MethodError<'tcx>> {
         debug!("probing for method names similar to {:?}", self.method_name);
 
@@ -2052,8 +2052,11 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         if self.matches_by_doc_alias(x.def_id) {
                             return true;
                         }
-                        match lev_distance_with_substrings(name.as_str(), x.name.as_str(), max_dist)
-                        {
+                        match edit_distance_with_substrings(
+                            name.as_str(),
+                            x.name.as_str(),
+                            max_dist,
+                        ) {
                             Some(d) => d > 0,
                             None => false,
                         }

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -31,7 +31,7 @@ use rustc_middle::ty::{self, DefIdTree, GenericArgKind, Ty, TyCtxt, TypeVisitabl
 use rustc_middle::ty::{IsSuggestable, ToPolyTraitRef};
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Symbol;
-use rustc_span::{lev_distance, source_map, ExpnKind, FileName, MacroKind, Span};
+use rustc_span::{edit_distance, source_map, ExpnKind, FileName, MacroKind, Span};
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::OnUnimplementedNote;
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::TypeErrCtxtExt as _;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
@@ -1014,7 +1014,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // that had unsatisfied trait bounds
         if unsatisfied_predicates.is_empty() && rcvr_ty.is_enum() {
             let adt_def = rcvr_ty.ty_adt_def().expect("enum is not an ADT");
-            if let Some(suggestion) = lev_distance::find_best_match_for_name(
+            if let Some(suggestion) = edit_distance::find_best_match_for_name(
                 &adt_def.variants().iter().map(|s| s.name).collect::<Vec<_>>(),
                 item_name.name,
                 None,

compiler/rustc_hir_typeck/src/pat.rs

@@ -14,8 +14,8 @@ use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKi
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::ty::{self, Adt, BindingMode, Ty, TypeVisitable};
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::DesugaringKind;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::{Span, Spanned};
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{BytePos, DUMMY_SP};

compiler/rustc_interface/src/util.rs

@@ -14,8 +14,8 @@ use rustc_session::filesearch::sysroot_candidates;
 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
 use rustc_session::parse::CrateConfig;
 use rustc_session::{early_error, filesearch, output, Session};
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::FileLoader;
 use rustc_span::symbol::{sym, Symbol};
 use session::CompilerIO;

compiler/rustc_lint/src/context.rs

@@ -39,7 +39,7 @@ use rustc_middle::ty::{self, print::Printer, subst::GenericArg, RegisteredTools,
 use rustc_session::lint::{BuiltinLintDiagnostics, LintExpectationId};
 use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId};
 use rustc_session::Session;
-use rustc_span::lev_distance::find_best_match_for_name;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{BytePos, Span};
 use rustc_target::abi;

compiler/rustc_parse/src/parser/item.rs

@@ -19,8 +19,8 @@ use rustc_errors::{
     struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, PResult,
     StashKey,
 };
+use rustc_span::edit_distance::edit_distance;
 use rustc_span::edition::Edition;
-use rustc_span::lev_distance::lev_distance;
 use rustc_span::source_map::{self, Span};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::DUMMY_SP;
@@ -459,7 +459,8 @@ impl<'a> Parser<'a> {
                 // Maybe the user misspelled `macro_rules` (issue #91227)
                 if self.token.is_ident()
                     && path.segments.len() == 1
-                    && lev_distance("macro_rules", &path.segments[0].ident.to_string(), 3).is_some()
+                    && edit_distance("macro_rules", &path.segments[0].ident.to_string(), 2)
+                        .is_some()
                 {
                     err.span_suggestion(
                         path.span,

compiler/rustc_resolve/src/diagnostics.rs

@@ -21,9 +21,9 @@ use rustc_session::lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE;
 use rustc_session::lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS;
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::Session;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::MacroKind;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, Span, SyntaxContext};

compiler/rustc_resolve/src/imports.rs

@@ -21,8 +21,8 @@ use rustc_middle::span_bug;
 use rustc_middle::ty;
 use rustc_session::lint::builtin::{PUB_USE_OF_PRIVATE_EXTERN_CRATE, UNUSED_IMPORTS};
 use rustc_session::lint::BuiltinLintDiagnostics;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::LocalExpnId;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, Ident, Symbol};
 use rustc_span::Span;
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -25,9 +25,9 @@ use rustc_middle::ty::DefIdTree;
 use rustc_session::lint;
 use rustc_session::parse::feature_err;
 use rustc_session::Session;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::MacroKind;
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, Span};
 
@@ -542,7 +542,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             }
         }
 
-        // Try Levenshtein algorithm.
+        // Try finding a suitable replacement.
         let typo_sugg =
             self.lookup_typo_candidate(path, source.namespace(), is_expected).to_opt_suggestion();
         if path.len() == 1 && self.self_type_is_available() {
@@ -770,7 +770,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 _ => {}
             }
 
-            // If the trait has a single item (which wasn't matched by Levenshtein), suggest it
+            // If the trait has a single item (which wasn't matched by the algorithm), suggest it
             let suggestion = self.get_single_associated_item(&path, &source, is_expected);
             if !self.r.add_typo_suggestion(err, suggestion, ident_span) {
                 fallback = !self.let_binding_suggestion(err, ident_span);