lifetime_names: &FxHashSet<ast::Ident>,
params: &[ElisionFailureInfo],
) {
- if count > 1 {
- err.span_label(span, format!("expected {} lifetime parameters", count));
- } else {
- let snippet = self.tcx.sess.source_map().span_to_snippet(span).ok();
- let suggest_existing = |err: &mut DiagnosticBuilder<'_>, sugg| {
- err.span_suggestion(
- span,
- "consider using the named lifetime",
- sugg,
- Applicability::MaybeIncorrect,
- );
- };
- let suggest_new = |err: &mut DiagnosticBuilder<'_>, sugg: &str| {
- err.span_label(span, "expected named lifetime parameter");
+ let snippet = self.tcx.sess.source_map().span_to_snippet(span).ok();
- for missing in self.missing_named_lifetime_spots.iter().rev() {
- let mut introduce_suggestion = vec![];
- let msg;
- let should_break;
- introduce_suggestion.push(match missing {
- MissingLifetimeSpot::Generics(generics) => {
- msg = "consider introducing a named lifetime parameter".to_string();
- should_break = true;
- if let Some(param) = generics.params.iter().find(|p| match p.kind {
- hir::GenericParamKind::Type {
- synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
- ..
- } => false,
- _ => true,
- }) {
- (param.span.shrink_to_lo(), "'a, ".to_string())
- } else {
- (generics.span, "<'a>".to_string())
- }
- }
- MissingLifetimeSpot::HigherRanked { span, span_type } => {
- msg = format!(
- "consider making the {} lifetime-generic with a new `'a` lifetime",
- span_type.descr(),
- );
- should_break = false;
- err.note(
- "for more information on higher-ranked polymorphism, visit \
- https://doc.rust-lang.org/nomicon/hrtb.html",
- );
- (*span, span_type.suggestion("'a"))
- }
- });
- for param in params {
- if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(param.span)
- {
- if snippet.starts_with('&') && !snippet.starts_with("&'") {
- introduce_suggestion
- .push((param.span, format!("&'a {}", &snippet[1..])));
- } else if snippet.starts_with("&'_ ") {
- introduce_suggestion
- .push((param.span, format!("&'a {}", &snippet[4..])));
- }
+ err.span_label(
+ span,
+ &format!(
+ "expected {} lifetime parameter{}",
+ if count == 1 { "named".to_string() } else { count.to_string() },
+ pluralize!(count)
+ ),
+ );
+
+ let suggest_existing = |err: &mut DiagnosticBuilder<'_>, sugg| {
+ err.span_suggestion_verbose(
+ span,
+ &format!("consider using the `{}` lifetime", lifetime_names.iter().next().unwrap()),
+ sugg,
+ Applicability::MaybeIncorrect,
+ );
+ };
+ let suggest_new = |err: &mut DiagnosticBuilder<'_>, sugg: &str| {
+ for missing in self.missing_named_lifetime_spots.iter().rev() {
+ let mut introduce_suggestion = vec![];
+ let msg;
+ let should_break;
+ introduce_suggestion.push(match missing {
+ MissingLifetimeSpot::Generics(generics) => {
+ msg = "consider introducing a named lifetime parameter".to_string();
+ should_break = true;
+ if let Some(param) = generics.params.iter().find(|p| match p.kind {
+ hir::GenericParamKind::Type {
+ synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
+ ..
+ } => false,
+ _ => true,
+ }) {
+ (param.span.shrink_to_lo(), "'a, ".to_string())
+ } else {
+ (generics.span, "<'a>".to_string())
}
}
- introduce_suggestion.push((span, sugg.to_string()));
- err.multipart_suggestion(
- &msg,
- introduce_suggestion,
- Applicability::MaybeIncorrect,
- );
- if should_break {
- break;
+ MissingLifetimeSpot::HigherRanked { span, span_type } => {
+ msg = format!(
+ "consider making the {} lifetime-generic with a new `'a` lifetime",
+ span_type.descr(),
+ );
+ should_break = false;
+ err.note(
+ "for more information on higher-ranked polymorphism, visit \
+ https://doc.rust-lang.org/nomicon/hrtb.html",
+ );
+ (*span, span_type.suggestion("'a"))
+ }
+ });
+ for param in params {
+ if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(param.span) {
+ if snippet.starts_with('&') && !snippet.starts_with("&'") {
+ introduce_suggestion
+ .push((param.span, format!("&'a {}", &snippet[1..])));
+ } else if snippet.starts_with("&'_ ") {
+ introduce_suggestion
+ .push((param.span, format!("&'a {}", &snippet[4..])));
+ }
}
}
- };
-
- match (lifetime_names.len(), lifetime_names.iter().next(), snippet.as_deref()) {
- (1, Some(name), Some("&")) => {
- suggest_existing(err, format!("&{} ", name));
- }
- (1, Some(name), Some("'_")) => {
- suggest_existing(err, name.to_string());
- }
- (1, Some(name), Some(snippet)) if !snippet.ends_with('>') => {
- suggest_existing(err, format!("{}<{}>", snippet, name));
- }
- (0, _, Some("&")) => {
- suggest_new(err, "&'a ");
- }
- (0, _, Some("'_")) => {
- suggest_new(err, "'a");
- }
- (0, _, Some(snippet)) if !snippet.ends_with('>') => {
- suggest_new(err, &format!("{}<'a>", snippet));
+ introduce_suggestion.push((span, sugg.to_string()));
+ err.multipart_suggestion(&msg, introduce_suggestion, Applicability::MaybeIncorrect);
+ if should_break {
+ break;
}
- _ => {
- err.span_label(span, "expected lifetime parameter");
+ }
+ };
+
+ match (lifetime_names.len(), lifetime_names.iter().next(), snippet.as_deref()) {
+ (1, Some(name), Some("&")) => {
+ suggest_existing(err, format!("&{} ", name));
+ }
+ (1, Some(name), Some("'_")) => {
+ suggest_existing(err, name.to_string());
+ }
+ (1, Some(name), Some("")) => {
+ suggest_existing(err, format!("{}, ", name).repeat(count));
+ }
+ (1, Some(name), Some(snippet)) if !snippet.ends_with('>') => {
+ suggest_existing(
+ err,
+ format!(
+ "{}<{}>",
+ snippet,
+ std::iter::repeat(name.to_string())
+ .take(count)
+ .collect::<Vec<_>>()
+ .join(", ")
+ ),
+ );
+ }
+ (0, _, Some("&")) if count == 1 => {
+ suggest_new(err, "&'a ");
+ }
+ (0, _, Some("'_")) if count == 1 => {
+ suggest_new(err, "'a");
+ }
+ (0, _, Some(snippet)) if !snippet.ends_with('>') && count == 1 => {
+ suggest_new(err, &format!("{}<'a>", snippet));
+ }
+ (n, ..) if n > 1 => {
+ let spans: Vec<Span> = lifetime_names.iter().map(|lt| lt.span).collect();
+ err.span_note(spans, "these named lifetimes are available to use");
+ if Some("") == snippet.as_deref() {
+ // This happens when we have `Foo<T>` where we point at the space before `T`,
+ // but this can be confusing so we give a suggestion with placeholders.
+ err.span_suggestion_verbose(
+ span,
+ "consider using one of the available lifetimes here",
+ "'lifetime, ".repeat(count),
+ Applicability::HasPlaceholders,
+ );
}
}
+ _ => {}
}
}
}
projects / rust.git / blobdiff