use std::cmp::Reverse; use errors::{Applicability, DiagnosticBuilder, DiagnosticId}; use log::debug; use rustc::hir::def::{self, CtorKind, Namespace::*}; use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId}; use rustc::session::{Session, config::nightly_options}; use syntax::ast::{self, Expr, ExprKind, Ident}; use syntax::ext::base::MacroKind; use syntax::symbol::{Symbol, keywords}; use syntax_pos::{BytePos, Span}; type Def = def::Def; use crate::macros::ParentScope; use crate::resolve_imports::{ImportDirective, ImportDirectiveSubclass, ImportResolver}; use crate::{import_candidate_to_enum_paths, is_self_type, is_self_value, path_names_to_string}; use crate::{AssocSuggestion, CrateLint, ImportSuggestion, ModuleOrUniformRoot, PathResult, PathSource, Resolver, Segment, Suggestion}; impl<'a> Resolver<'a> { /// Handles error reporting for `smart_resolve_path_fragment` function. /// Creates base error and amends it with one short label and possibly some longer helps/notes. pub(crate) fn smart_resolve_report_errors( &mut self, path: &[Segment], span: Span, source: PathSource<'_>, def: Option, ) -> (DiagnosticBuilder<'a>, Vec) { let ident_span = path.last().map_or(span, |ident| ident.ident.span); let ns = source.namespace(); let is_expected = &|def| source.is_expected(def); let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false }; // Make the base error. let expected = source.descr_expected(); let path_str = Segment::names_to_string(path); let item_str = path.last().unwrap().ident; let code = source.error_code(def.is_some()); let (base_msg, fallback_label, base_span) = if let Some(def) = def { (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str), format!("not a {}", expected), span) } else { let item_span = path.last().unwrap().ident.span; let (mod_prefix, mod_str) = if path.len() == 1 { (String::new(), "this scope".to_string()) } else if path.len() == 2 && path[0].ident.name == keywords::PathRoot.name() { (String::new(), "the crate root".to_string()) } else { let mod_path = &path[..path.len() - 1]; let mod_prefix = match self.resolve_path_without_parent_scope( mod_path, Some(TypeNS), false, span, CrateLint::No ) { PathResult::Module(ModuleOrUniformRoot::Module(module)) => module.def(), _ => None, }.map_or(String::new(), |def| format!("{} ", def.kind_name())); (mod_prefix, format!("`{}`", Segment::names_to_string(mod_path))) }; (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str), format!("not found in {}", mod_str), item_span) }; let code = DiagnosticId::Error(code.into()); let mut err = self.session.struct_span_err_with_code(base_span, &base_msg, code); // Emit help message for fake-self from other languages (e.g., `this` in Javascript). if ["this", "my"].contains(&&*item_str.as_str()) && self.self_value_is_available(path[0].ident.span, span) { err.span_suggestion( span, "did you mean", "self".to_string(), Applicability::MaybeIncorrect, ); } // Emit special messages for unresolved `Self` and `self`. if is_self_type(path, ns) { __diagnostic_used!(E0411); err.code(DiagnosticId::Error("E0411".into())); err.span_label(span, format!("`Self` is only available in impls, traits, \ and type definitions")); return (err, Vec::new()); } if is_self_value(path, ns) { debug!("smart_resolve_path_fragment: E0424, source={:?}", source); __diagnostic_used!(E0424); err.code(DiagnosticId::Error("E0424".into())); err.span_label(span, match source { PathSource::Pat => { format!("`self` value is a keyword \ and may not be bound to \ variables or shadowed") } _ => { format!("`self` value is a keyword \ only available in methods \ with `self` parameter") } }); return (err, Vec::new()); } // Try to lookup name in more relaxed fashion for better error reporting. let ident = path.last().unwrap().ident; let candidates = self.lookup_import_candidates(ident, ns, is_expected) .drain(..) .filter(|ImportSuggestion { did, .. }| { match (did, def.and_then(|def| def.opt_def_id())) { (Some(suggestion_did), Some(actual_did)) => *suggestion_did != actual_did, _ => true, } }) .collect::>(); if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) { let enum_candidates = self.lookup_import_candidates(ident, ns, is_enum_variant); let mut enum_candidates = enum_candidates.iter() .map(|suggestion| { import_candidate_to_enum_paths(&suggestion) }).collect::>(); enum_candidates.sort(); if !enum_candidates.is_empty() { // Contextualize for E0412 "cannot find type", but don't belabor the point // (that it's a variant) for E0573 "expected type, found variant". let preamble = if def.is_none() { let others = match enum_candidates.len() { 1 => String::new(), 2 => " and 1 other".to_owned(), n => format!(" and {} others", n) }; format!("there is an enum variant `{}`{}; ", enum_candidates[0].0, others) } else { String::new() }; let msg = format!("{}try using the variant's enum", preamble); err.span_suggestions( span, &msg, enum_candidates.into_iter() .map(|(_variant_path, enum_ty_path)| enum_ty_path) // Variants re-exported in prelude doesn't mean `prelude::v1` is the // type name! // FIXME: is there a more principled way to do this that // would work for other re-exports? .filter(|enum_ty_path| enum_ty_path != "std::prelude::v1") // Also write `Option` rather than `std::prelude::v1::Option`. .map(|enum_ty_path| { // FIXME #56861: DRY-er prelude filtering. enum_ty_path.trim_start_matches("std::prelude::v1::").to_owned() }), Applicability::MachineApplicable, ); } } if path.len() == 1 && self.self_type_is_available(span) { if let Some(candidate) = self.lookup_assoc_candidate(ident, ns, is_expected) { let self_is_available = self.self_value_is_available(path[0].ident.span, span); match candidate { AssocSuggestion::Field => { if self_is_available { err.span_suggestion( span, "you might have meant to use the available field", format!("self.{}", path_str), Applicability::MachineApplicable, ); } else { err.span_label( span, "a field by this name exists in `Self`", ); } } AssocSuggestion::MethodWithSelf if self_is_available => { err.span_suggestion( span, "try", format!("self.{}", path_str), Applicability::MachineApplicable, ); } AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => { err.span_suggestion( span, "try", format!("Self::{}", path_str), Applicability::MachineApplicable, ); } } return (err, candidates); } } let mut levenshtein_worked = false; // Try Levenshtein algorithm. let suggestion = self.lookup_typo_candidate(path, ns, is_expected, span); if let Some(suggestion) = suggestion { let msg = format!( "{} {} with a similar name exists", suggestion.article, suggestion.kind ); err.span_suggestion( ident_span, &msg, suggestion.candidate.to_string(), Applicability::MaybeIncorrect, ); levenshtein_worked = true; } // Try context-dependent help if relaxed lookup didn't work. if let Some(def) = def { if self.smart_resolve_context_dependent_help(&mut err, span, source, def, &path_str, &fallback_label) { return (err, candidates); } } // Fallback label. if !levenshtein_worked { err.span_label(base_span, fallback_label); self.type_ascription_suggestion(&mut err, base_span); } (err, candidates) } fn followed_by_brace(&self, span: Span) -> (bool, Option<(Span, String)>) { // HACK(estebank): find a better way to figure out that this was a // parser issue where a struct literal is being used on an expression // where a brace being opened means a block is being started. Look // ahead for the next text to see if `span` is followed by a `{`. let sm = self.session.source_map(); let mut sp = span; loop { sp = sm.next_point(sp); match sm.span_to_snippet(sp) { Ok(ref snippet) => { if snippet.chars().any(|c| { !c.is_whitespace() }) { break; } } _ => break, } } let followed_by_brace = match sm.span_to_snippet(sp) { Ok(ref snippet) if snippet == "{" => true, _ => false, }; // In case this could be a struct literal that needs to be surrounded // by parenthesis, find the appropriate span. let mut i = 0; let mut closing_brace = None; loop { sp = sm.next_point(sp); match sm.span_to_snippet(sp) { Ok(ref snippet) => { if snippet == "}" { let sp = span.to(sp); if let Ok(snippet) = sm.span_to_snippet(sp) { closing_brace = Some((sp, snippet)); } break; } } _ => break, } i += 1; // The bigger the span, the more likely we're incorrect -- // bound it to 100 chars long. if i > 100 { break; } } return (followed_by_brace, closing_brace) } /// Provides context-dependent help for errors reported by the `smart_resolve_path_fragment` /// function. /// Returns `true` if able to provide context-dependent help. fn smart_resolve_context_dependent_help( &mut self, err: &mut DiagnosticBuilder<'a>, span: Span, source: PathSource<'_>, def: Def, path_str: &str, fallback_label: &str, ) -> bool { let ns = source.namespace(); let is_expected = &|def| source.is_expected(def); let path_sep = |err: &mut DiagnosticBuilder<'_>, expr: &Expr| match expr.node { ExprKind::Field(_, ident) => { err.span_suggestion( expr.span, "use the path separator to refer to an item", format!("{}::{}", path_str, ident), Applicability::MaybeIncorrect, ); true } ExprKind::MethodCall(ref segment, ..) => { let span = expr.span.with_hi(segment.ident.span.hi()); err.span_suggestion( span, "use the path separator to refer to an item", format!("{}::{}", path_str, segment.ident), Applicability::MaybeIncorrect, ); true } _ => false, }; let mut bad_struct_syntax_suggestion = || { let (followed_by_brace, closing_brace) = self.followed_by_brace(span); let mut suggested = false; match source { PathSource::Expr(Some(parent)) => { suggested = path_sep(err, &parent); } PathSource::Expr(None) if followed_by_brace == true => { if let Some((sp, snippet)) = closing_brace { err.span_suggestion( sp, "surround the struct literal with parenthesis", format!("({})", snippet), Applicability::MaybeIncorrect, ); } else { err.span_label( span, // Note the parenthesis surrounding the suggestion below format!("did you mean `({} {{ /* fields */ }})`?", path_str), ); } suggested = true; }, _ => {} } if !suggested { err.span_label( span, format!("did you mean `{} {{ /* fields */ }}`?", path_str), ); } }; match (def, source) { (Def::Macro(..), _) => { err.span_suggestion( span, "use `!` to invoke the macro", format!("{}!", path_str), Applicability::MaybeIncorrect, ); if path_str == "try" && span.rust_2015() { err.note("if you want the `try` keyword, you need to be in the 2018 edition"); } } (Def::TyAlias(..), PathSource::Trait(_)) => { err.span_label(span, "type aliases cannot be used as traits"); if nightly_options::is_nightly_build() { err.note("did you mean to use a trait alias?"); } } (Def::Mod(..), PathSource::Expr(Some(parent))) => if !path_sep(err, &parent) { return false; }, (Def::Enum(..), PathSource::TupleStruct) | (Def::Enum(..), PathSource::Expr(..)) => { if let Some(variants) = self.collect_enum_variants(def) { if !variants.is_empty() { let msg = if variants.len() == 1 { "try using the enum's variant" } else { "try using one of the enum's variants" }; err.span_suggestions( span, msg, variants.iter().map(path_names_to_string), Applicability::MaybeIncorrect, ); } } else { err.note("did you mean to use one of the enum's variants?"); } }, (Def::Struct(def_id), _) if ns == ValueNS => { if let Some((ctor_def, ctor_vis)) = self.struct_constructors.get(&def_id).cloned() { let accessible_ctor = self.is_accessible(ctor_vis); if is_expected(ctor_def) && !accessible_ctor { err.span_label( span, format!("constructor is not visible here due to private fields"), ); } } else { bad_struct_syntax_suggestion(); } } (Def::Union(..), _) | (Def::Variant(..), _) | (Def::Ctor(_, _, CtorKind::Fictive), _) if ns == ValueNS => { bad_struct_syntax_suggestion(); } (Def::SelfTy(..), _) if ns == ValueNS => { err.span_label(span, fallback_label); err.note("can't use `Self` as a constructor, you must use the implemented struct"); } (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => { err.note("can't use a type alias as a constructor"); } _ => return false, } true } } impl<'a, 'b:'a> ImportResolver<'a, 'b> { /// Adds suggestions for a path that cannot be resolved. pub(crate) fn make_path_suggestion( &mut self, span: Span, mut path: Vec, parent_scope: &ParentScope<'b>, ) -> Option<(Vec, Vec)> { debug!("make_path_suggestion: span={:?} path={:?}", span, path); match (path.get(0), path.get(1)) { // `{{root}}::ident::...` on both editions. // On 2015 `{{root}}` is usually added implicitly. (Some(fst), Some(snd)) if fst.ident.name == keywords::PathRoot.name() && !snd.ident.is_path_segment_keyword() => {} // `ident::...` on 2018. (Some(fst), _) if fst.ident.span.rust_2018() && !fst.ident.is_path_segment_keyword() => { // Insert a placeholder that's later replaced by `self`/`super`/etc. path.insert(0, Segment::from_ident(keywords::Invalid.ident())); } _ => return None, } self.make_missing_self_suggestion(span, path.clone(), parent_scope) .or_else(|| self.make_missing_crate_suggestion(span, path.clone(), parent_scope)) .or_else(|| self.make_missing_super_suggestion(span, path.clone(), parent_scope)) .or_else(|| self.make_external_crate_suggestion(span, path, parent_scope)) } /// Suggest a missing `self::` if that resolves to an correct module. /// /// ``` /// | /// LL | use foo::Bar; /// | ^^^ did you mean `self::foo`? /// ``` fn make_missing_self_suggestion( &mut self, span: Span, mut path: Vec, parent_scope: &ParentScope<'b>, ) -> Option<(Vec, Vec)> { // Replace first ident with `self` and check if that is valid. path[0].ident.name = keywords::SelfLower.name(); let result = self.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); debug!("make_missing_self_suggestion: path={:?} result={:?}", path, result); if let PathResult::Module(..) = result { Some((path, Vec::new())) } else { None } } /// Suggests a missing `crate::` if that resolves to an correct module. /// /// ``` /// | /// LL | use foo::Bar; /// | ^^^ did you mean `crate::foo`? /// ``` fn make_missing_crate_suggestion( &mut self, span: Span, mut path: Vec, parent_scope: &ParentScope<'b>, ) -> Option<(Vec, Vec)> { // Replace first ident with `crate` and check if that is valid. path[0].ident.name = keywords::Crate.name(); let result = self.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); debug!("make_missing_crate_suggestion: path={:?} result={:?}", path, result); if let PathResult::Module(..) = result { Some(( path, vec![ "`use` statements changed in Rust 2018; read more at \ ".to_string() ], )) } else { None } } /// Suggests a missing `super::` if that resolves to an correct module. /// /// ``` /// | /// LL | use foo::Bar; /// | ^^^ did you mean `super::foo`? /// ``` fn make_missing_super_suggestion( &mut self, span: Span, mut path: Vec, parent_scope: &ParentScope<'b>, ) -> Option<(Vec, Vec)> { // Replace first ident with `crate` and check if that is valid. path[0].ident.name = keywords::Super.name(); let result = self.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); debug!("make_missing_super_suggestion: path={:?} result={:?}", path, result); if let PathResult::Module(..) = result { Some((path, Vec::new())) } else { None } } /// Suggests a missing external crate name if that resolves to an correct module. /// /// ``` /// | /// LL | use foobar::Baz; /// | ^^^^^^ did you mean `baz::foobar`? /// ``` /// /// Used when importing a submodule of an external crate but missing that crate's /// name as the first part of path. fn make_external_crate_suggestion( &mut self, span: Span, mut path: Vec, parent_scope: &ParentScope<'b>, ) -> Option<(Vec, Vec)> { if path[1].ident.span.rust_2015() { return None; } // Sort extern crate names in reverse order to get // 1) some consistent ordering for emitted dignostics, and // 2) `std` suggestions before `core` suggestions. let mut extern_crate_names = self.resolver.extern_prelude.iter().map(|(ident, _)| ident.name).collect::>(); extern_crate_names.sort_by_key(|name| Reverse(name.as_str())); for name in extern_crate_names.into_iter() { // Replace first ident with a crate name and check if that is valid. path[0].ident.name = name; let result = self.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); debug!("make_external_crate_suggestion: name={:?} path={:?} result={:?}", name, path, result); if let PathResult::Module(..) = result { return Some((path, Vec::new())); } } None } /// Suggests importing a macro from the root of the crate rather than a module within /// the crate. /// /// ``` /// help: a macro with this name exists at the root of the crate /// | /// LL | use issue_59764::makro; /// | ^^^^^^^^^^^^^^^^^^ /// | /// = note: this could be because a macro annotated with `#[macro_export]` will be exported /// at the root of the crate instead of the module where it is defined /// ``` pub(crate) fn check_for_module_export_macro( &self, directive: &'b ImportDirective<'b>, module: ModuleOrUniformRoot<'b>, ident: Ident, ) -> Option<(Option, Vec)> { let mut crate_module = if let ModuleOrUniformRoot::Module(module) = module { module } else { return None; }; while let Some(parent) = crate_module.parent { crate_module = parent; } if ModuleOrUniformRoot::same_def(ModuleOrUniformRoot::Module(crate_module), module) { // Don't make a suggestion if the import was already from the root of the // crate. return None; } let resolutions = crate_module.resolutions.borrow(); let resolution = resolutions.get(&(ident, MacroNS))?; let binding = resolution.borrow().binding()?; if let Def::Macro(_, MacroKind::Bang) = binding.def() { let module_name = crate_module.kind.name().unwrap(); let import = match directive.subclass { ImportDirectiveSubclass::SingleImport { source, target, .. } if source != target => format!("{} as {}", source, target), _ => format!("{}", ident), }; let mut corrections: Vec<(Span, String)> = Vec::new(); if !directive.is_nested() { // Assume this is the easy case of `use issue_59764::foo::makro;` and just remove // intermediate segments. corrections.push((directive.span, format!("{}::{}", module_name, import))); } else { // Find the binding span (and any trailing commas and spaces). // ie. `use a::b::{c, d, e};` // ^^^ let (found_closing_brace, binding_span) = find_span_of_binding_until_next_binding( self.resolver.session, directive.span, directive.use_span, ); debug!("check_for_module_export_macro: found_closing_brace={:?} binding_span={:?}", found_closing_brace, binding_span); let mut removal_span = binding_span; if found_closing_brace { // If the binding span ended with a closing brace, as in the below example: // ie. `use a::b::{c, d};` // ^ // Then expand the span of characters to remove to include the previous // binding's trailing comma. // ie. `use a::b::{c, d};` // ^^^ if let Some(previous_span) = extend_span_to_previous_binding( self.resolver.session, binding_span, ) { debug!("check_for_module_export_macro: previous_span={:?}", previous_span); removal_span = removal_span.with_lo(previous_span.lo()); } } debug!("check_for_module_export_macro: removal_span={:?}", removal_span); // Remove the `removal_span`. corrections.push((removal_span, "".to_string())); // Find the span after the crate name and if it has nested imports immediatately // after the crate name already. // ie. `use a::b::{c, d};` // ^^^^^^^^^ // or `use a::{b, c, d}};` // ^^^^^^^^^^^ let (has_nested, after_crate_name) = find_span_immediately_after_crate_name( self.resolver.session, module_name, directive.use_span, ); debug!("check_for_module_export_macro: has_nested={:?} after_crate_name={:?}", has_nested, after_crate_name); let source_map = self.resolver.session.source_map(); // Add the import to the start, with a `{` if required. let start_point = source_map.start_point(after_crate_name); if let Ok(start_snippet) = source_map.span_to_snippet(start_point) { corrections.push(( start_point, if has_nested { // In this case, `start_snippet` must equal '{'. format!("{}{}, ", start_snippet, import) } else { // In this case, add a `{`, then the moved import, then whatever // was there before. format!("{{{}, {}", import, start_snippet) } )); } // Add a `};` to the end if nested, matching the `{` added at the start. if !has_nested { corrections.push((source_map.end_point(after_crate_name), "};".to_string())); } } let suggestion = Some(( corrections, String::from("a macro with this name exists at the root of the crate"), Applicability::MaybeIncorrect, )); let note = vec![ "this could be because a macro annotated with `#[macro_export]` will be exported \ at the root of the crate instead of the module where it is defined".to_string(), ]; Some((suggestion, note)) } else { None } } } /// Given a `binding_span` of a binding within a use statement: /// /// ``` /// use foo::{a, b, c}; /// ^ /// ``` /// /// then return the span until the next binding or the end of the statement: /// /// ``` /// use foo::{a, b, c}; /// ^^^ /// ``` pub(crate) fn find_span_of_binding_until_next_binding( sess: &Session, binding_span: Span, use_span: Span, ) -> (bool, Span) { let source_map = sess.source_map(); // Find the span of everything after the binding. // ie. `a, e};` or `a};` let binding_until_end = binding_span.with_hi(use_span.hi()); // Find everything after the binding but not including the binding. // ie. `, e};` or `};` let after_binding_until_end = binding_until_end.with_lo(binding_span.hi()); // Keep characters in the span until we encounter something that isn't a comma or // whitespace. // ie. `, ` or ``. // // Also note whether a closing brace character was encountered. If there // was, then later go backwards to remove any trailing commas that are left. let mut found_closing_brace = false; let after_binding_until_next_binding = source_map.span_take_while( after_binding_until_end, |&ch| { if ch == '}' { found_closing_brace = true; } ch == ' ' || ch == ',' } ); // Combine the two spans. // ie. `a, ` or `a`. // // Removing these would leave `issue_52891::{d, e};` or `issue_52891::{d, e, };` let span = binding_span.with_hi(after_binding_until_next_binding.hi()); (found_closing_brace, span) } /// Given a `binding_span`, return the span through to the comma or opening brace of the previous /// binding. /// /// ``` /// use foo::a::{a, b, c}; /// ^^--- binding span /// | /// returned span /// /// use foo::{a, b, c}; /// --- binding span /// ``` pub(crate) fn extend_span_to_previous_binding( sess: &Session, binding_span: Span, ) -> Option { let source_map = sess.source_map(); // `prev_source` will contain all of the source that came before the span. // Then split based on a command and take the first (ie. closest to our span) // snippet. In the example, this is a space. let prev_source = source_map.span_to_prev_source(binding_span).ok()?; let prev_comma = prev_source.rsplit(',').collect::>(); let prev_starting_brace = prev_source.rsplit('{').collect::>(); if prev_comma.len() <= 1 || prev_starting_brace.len() <= 1 { return None; } let prev_comma = prev_comma.first().unwrap(); let prev_starting_brace = prev_starting_brace.first().unwrap(); // If the amount of source code before the comma is greater than // the amount of source code before the starting brace then we've only // got one item in the nested item (eg. `issue_52891::{self}`). if prev_comma.len() > prev_starting_brace.len() { return None; } Some(binding_span.with_lo(BytePos( // Take away the number of bytes for the characters we've found and an // extra for the comma. binding_span.lo().0 - (prev_comma.as_bytes().len() as u32) - 1 ))) } /// Given a `use_span` of a binding within a use statement, returns the highlighted span and if /// it is a nested use tree. /// /// ``` /// use foo::a::{b, c}; /// ^^^^^^^^^^ // false /// /// use foo::{a, b, c}; /// ^^^^^^^^^^ // true /// /// use foo::{a, b::{c, d}}; /// ^^^^^^^^^^^^^^^ // true /// ``` fn find_span_immediately_after_crate_name( sess: &Session, module_name: Symbol, use_span: Span, ) -> (bool, Span) { debug!("find_span_immediately_after_crate_name: module_name={:?} use_span={:?}", module_name, use_span); let source_map = sess.source_map(); // Using `use issue_59764::foo::{baz, makro};` as an example throughout.. let mut num_colons = 0; // Find second colon.. `use issue_59764:` let until_second_colon = source_map.span_take_while(use_span, |c| { if *c == ':' { num_colons += 1; } match c { ':' if num_colons == 2 => false, _ => true, } }); // Find everything after the second colon.. `foo::{baz, makro};` let from_second_colon = use_span.with_lo(until_second_colon.hi() + BytePos(1)); let mut found_a_non_whitespace_character = false; // Find the first non-whitespace character in `from_second_colon`.. `f` let after_second_colon = source_map.span_take_while(from_second_colon, |c| { if found_a_non_whitespace_character { return false; } if !c.is_whitespace() { found_a_non_whitespace_character = true; } true }); // Find the first `{` in from_second_colon.. `foo::{` let next_left_bracket = source_map.span_through_char(from_second_colon, '{'); (next_left_bracket == after_second_colon, from_second_colon) }