feat: implement error recovery in expected_ident_found
This commit is contained in:
parent
b4e17a5098
commit
05b5046633
8 changed files with 184 additions and 78 deletions
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@ -269,13 +269,18 @@ impl<'a> Parser<'a> {
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}
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}
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/// Emits an error with suggestions if an identifier was expected but not found.
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/// Emits an error with suggestions if an identifier was expected but not found.
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pub(super) fn expected_ident_found(&mut self) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
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///
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/// Returns a possibly recovered identifier.
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pub(super) fn expected_ident_found(
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&mut self,
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recover: bool,
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) -> PResult<'a, (Ident, /* is_raw */ bool)> {
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if let TokenKind::DocComment(..) = self.prev_token.kind {
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if let TokenKind::DocComment(..) = self.prev_token.kind {
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return DocCommentDoesNotDocumentAnything {
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return Err(DocCommentDoesNotDocumentAnything {
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span: self.prev_token.span,
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span: self.prev_token.span,
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missing_comma: None,
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missing_comma: None,
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}
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}
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.into_diagnostic(&self.sess.span_diagnostic);
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.into_diagnostic(&self.sess.span_diagnostic));
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}
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}
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let valid_follow = &[
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let valid_follow = &[
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@ -290,34 +295,51 @@ impl<'a> Parser<'a> {
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TokenKind::CloseDelim(Delimiter::Parenthesis),
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TokenKind::CloseDelim(Delimiter::Parenthesis),
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];
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];
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let suggest_raw = match self.token.ident() {
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let mut recovered_ident = None;
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Some((ident, false))
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// we take this here so that the correct original token is retained in
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if ident.is_raw_guess()
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// the diagnostic, regardless of eager recovery.
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&& self.look_ahead(1, |t| valid_follow.contains(&t.kind)) =>
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let bad_token = self.token.clone();
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{
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Some(SuggEscapeIdentifier {
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span: ident.span.shrink_to_lo(),
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// `Symbol::to_string()` is different from `Symbol::into_diagnostic_arg()`,
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// which uses `Symbol::to_ident_string()` and "helpfully" adds an implicit `r#`
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ident_name: ident.name.to_string(),
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})
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}
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_ => None,
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};
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let suggest_remove_comma = (self.token == token::Comma
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// suggest prepending a keyword in identifier position with `r#`
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&& self.look_ahead(1, |t| t.is_ident()))
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let suggest_raw = if let Some((ident, false)) = self.token.ident()
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.then_some(SuggRemoveComma { span: self.token.span });
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&& ident.is_raw_guess()
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&& self.look_ahead(1, |t| valid_follow.contains(&t.kind))
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{
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recovered_ident = Some((ident, true));
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let help_cannot_start_number = self.is_lit_bad_ident().map(|(len, _valid_portion)| {
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// `Symbol::to_string()` is different from `Symbol::into_diagnostic_arg()`,
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let (invalid, _valid) = self.token.span.split_at(len as u32);
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// which uses `Symbol::to_ident_string()` and "helpfully" adds an implicit `r#`
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let ident_name = ident.name.to_string();
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Some(SuggEscapeIdentifier {
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span: ident.span.shrink_to_lo(),
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ident_name
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})
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} else { None };
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let suggest_remove_comma =
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if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
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if recover {
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self.bump();
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recovered_ident = self.ident_or_err(false).ok();
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};
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Some(SuggRemoveComma { span: bad_token.span })
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} else {
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None
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};
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let help_cannot_start_number = self.is_lit_bad_ident().map(|(len, valid_portion)| {
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let (invalid, valid) = self.token.span.split_at(len as u32);
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recovered_ident = Some((Ident::new(valid_portion, valid), false));
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HelpIdentifierStartsWithNumber { num_span: invalid }
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HelpIdentifierStartsWithNumber { num_span: invalid }
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});
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});
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let err = ExpectedIdentifier {
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let err = ExpectedIdentifier {
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span: self.token.span,
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span: bad_token.span,
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token: self.token.clone(),
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token: bad_token,
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suggest_raw,
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suggest_raw,
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suggest_remove_comma,
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suggest_remove_comma,
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help_cannot_start_number,
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help_cannot_start_number,
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@ -326,6 +348,7 @@ impl<'a> Parser<'a> {
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// if the token we have is a `<`
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// if the token we have is a `<`
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// it *might* be a misplaced generic
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// it *might* be a misplaced generic
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// FIXME: could we recover with this?
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if self.token == token::Lt {
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if self.token == token::Lt {
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// all keywords that could have generic applied
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// all keywords that could have generic applied
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let valid_prev_keywords =
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let valid_prev_keywords =
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@ -376,7 +399,16 @@ impl<'a> Parser<'a> {
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}
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}
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}
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}
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err
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if let Some(recovered_ident) = recovered_ident && recover {
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err.emit();
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Ok(recovered_ident)
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} else {
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Err(err)
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}
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}
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pub(super) fn expected_ident_found_err(&mut self) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
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self.expected_ident_found(false).unwrap_err()
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}
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}
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/// Checks if the current token is a integer or float literal and looks like
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/// Checks if the current token is a integer or float literal and looks like
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@ -392,7 +424,7 @@ impl<'a> Parser<'a> {
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kind: token::LitKind::Integer | token::LitKind::Float,
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kind: token::LitKind::Integer | token::LitKind::Float,
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symbol,
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symbol,
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suffix,
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suffix,
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}) = self.token.uninterpolate().kind
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}) = self.token.kind
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&& rustc_ast::MetaItemLit::from_token(&self.token).is_none()
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&& rustc_ast::MetaItemLit::from_token(&self.token).is_none()
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{
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{
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Some((symbol.as_str().len(), suffix.unwrap()))
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Some((symbol.as_str().len(), suffix.unwrap()))
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@ -1181,7 +1181,7 @@ impl<'a> Parser<'a> {
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defaultness: Defaultness,
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defaultness: Defaultness,
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) -> PResult<'a, ItemInfo> {
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) -> PResult<'a, ItemInfo> {
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let impl_span = self.token.span;
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let impl_span = self.token.span;
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let mut err = self.expected_ident_found();
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let mut err = self.expected_ident_found_err();
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// Only try to recover if this is implementing a trait for a type
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// Only try to recover if this is implementing a trait for a type
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let mut impl_info = match self.parse_item_impl(attrs, defaultness) {
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let mut impl_info = match self.parse_item_impl(attrs, defaultness) {
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@ -1776,7 +1776,7 @@ impl<'a> Parser<'a> {
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Err(err) => {
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Err(err) => {
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err.cancel();
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err.cancel();
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self.restore_snapshot(snapshot);
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self.restore_snapshot(snapshot);
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self.expected_ident_found()
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self.expected_ident_found_err()
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}
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}
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}
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}
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} else if self.eat_keyword(kw::Struct) {
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} else if self.eat_keyword(kw::Struct) {
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@ -1792,11 +1792,11 @@ impl<'a> Parser<'a> {
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Err(err) => {
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Err(err) => {
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err.cancel();
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err.cancel();
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self.restore_snapshot(snapshot);
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self.restore_snapshot(snapshot);
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self.expected_ident_found()
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self.expected_ident_found_err()
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}
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}
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}
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}
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} else {
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} else {
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let mut err = self.expected_ident_found();
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let mut err = self.expected_ident_found_err();
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if self.eat_keyword_noexpect(kw::Let)
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if self.eat_keyword_noexpect(kw::Let)
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&& let removal_span = self.prev_token.span.until(self.token.span)
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&& let removal_span = self.prev_token.span.until(self.token.span)
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&& let Ok(ident) = self.parse_ident_common(false)
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&& let Ok(ident) = self.parse_ident_common(false)
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@ -553,8 +553,9 @@ impl<'a> Parser<'a> {
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fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> {
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fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> {
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let (ident, is_raw) = self.ident_or_err(recover)?;
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let (ident, is_raw) = self.ident_or_err(recover)?;
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if !is_raw && ident.is_reserved() {
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if !is_raw && ident.is_reserved() {
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let mut err = self.expected_ident_found();
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let mut err = self.expected_ident_found_err();
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if recover {
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if recover {
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err.emit();
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err.emit();
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} else {
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} else {
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@ -565,12 +566,16 @@ impl<'a> Parser<'a> {
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Ok(ident)
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Ok(ident)
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}
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}
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fn ident_or_err(&mut self, _recover: bool) -> PResult<'a, (Ident, /* is_raw */ bool)> {
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fn ident_or_err(&mut self, recover: bool) -> PResult<'a, (Ident, /* is_raw */ bool)> {
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let result = self.token.ident().ok_or_else(|| self.expected_ident_found());
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let result = self.token.ident().ok_or_else(|| self.expected_ident_found(recover));
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let (ident, is_raw) = match result {
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let (ident, is_raw) = match result {
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Ok(ident) => ident,
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Ok(ident) => ident,
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Err(err) => return Err(err),
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Err(err) => match err {
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// we recovered!
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Ok(ident) => ident,
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Err(err) => return Err(err),
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},
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};
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};
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Ok((ident, is_raw))
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Ok((ident, is_raw))
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@ -391,7 +391,13 @@ impl<'a> Parser<'a> {
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} else {
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} else {
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PatKind::Lit(const_expr)
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PatKind::Lit(const_expr)
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}
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}
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} else if self.can_be_ident_pat() || self.is_lit_bad_ident().is_some() {
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// Don't eagerly error on semantically invalid tokens when matching
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// declarative macros, as the input to those doesn't have to be
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// semantically valid. For attribute/derive proc macros this is not the
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// case, so doing the recovery for them is fine.
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} else if self.can_be_ident_pat()
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|| (self.is_lit_bad_ident().is_some() && self.may_recover())
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{
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// Parse `ident @ pat`
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// Parse `ident @ pat`
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// This can give false positives and parse nullary enums,
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// This can give false positives and parse nullary enums,
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// they are dealt with later in resolve.
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// they are dealt with later in resolve.
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@ -590,7 +596,7 @@ impl<'a> Parser<'a> {
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// Make sure we don't allow e.g. `let mut $p;` where `$p:pat`.
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// Make sure we don't allow e.g. `let mut $p;` where `$p:pat`.
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if let token::Interpolated(nt) = &self.token.kind {
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if let token::Interpolated(nt) = &self.token.kind {
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if let token::NtPat(_) = **nt {
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if let token::NtPat(_) = **nt {
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self.expected_ident_found().emit();
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self.expected_ident_found_err().emit();
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}
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}
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}
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}
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16
tests/ui/parser/ident-recovery.rs
Normal file
16
tests/ui/parser/ident-recovery.rs
Normal file
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@ -0,0 +1,16 @@
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fn ,comma() {
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//~^ ERROR expected identifier, found `,`
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struct Foo {
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x: i32,,
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//~^ ERROR expected identifier, found `,`
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y: u32,
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}
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}
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fn break() {
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//~^ ERROR expected identifier, found keyword `break`
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let continue = 5;
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//~^ ERROR expected identifier, found keyword `continue`
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}
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fn main() {}
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42
tests/ui/parser/ident-recovery.stderr
Normal file
42
tests/ui/parser/ident-recovery.stderr
Normal file
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@ -0,0 +1,42 @@
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error: expected identifier, found `,`
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--> $DIR/ident-recovery.rs:1:4
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LL | fn ,comma() {
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| ^
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| |
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| expected identifier
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| help: remove this comma
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error: expected identifier, found `,`
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--> $DIR/ident-recovery.rs:4:16
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LL | x: i32,,
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| ^
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| expected identifier
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| help: remove this comma
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error: expected identifier, found keyword `break`
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--> $DIR/ident-recovery.rs:10:4
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LL | fn break() {
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| ^^^^^ expected identifier, found keyword
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help: escape `break` to use it as an identifier
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LL | fn r#break() {
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| ++
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error: expected identifier, found keyword `continue`
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--> $DIR/ident-recovery.rs:12:9
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LL | let continue = 5;
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| ^^^^^^^^ expected identifier, found keyword
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help: escape `continue` to use it as an identifier
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LL | let r#continue = 5;
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| ++
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error: aborting due to 4 previous errors
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@ -1,26 +1,19 @@
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fn test() {
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fn 1234test() {
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//~^ ERROR expected identifier, found `1234test`
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if let 123 = 123 { println!("yes"); }
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if let 123 = 123 { println!("yes"); }
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}
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fn test_2() {
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if let 2e1 = 123 {
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//~^ ERROR mismatched types
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}
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let 23name = 123;
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//~^ ERROR expected identifier, found `23name`
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let 2x: i32 = 123;
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//~^ ERROR expected identifier, found `2x`
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let 1x = 123;
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let 1x = 123;
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//~^ ERROR expected identifier, found `1x`
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//~^ ERROR expected identifier, found `1x`
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}
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}
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fn test_3() {
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let 2x: i32 = 123;
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//~^ ERROR expected identifier, found `2x`
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}
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fn test_4() {
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if let 2e1 = 123 {
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//~^ ERROR mismatched types
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}
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}
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fn test_5() {
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let 23name = 123;
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//~^ ERROR expected identifier, found `23name`
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}
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fn main() {}
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fn main() {}
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@ -1,47 +1,59 @@
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error: expected identifier, found `1x`
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error: expected identifier, found `1234test`
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--> $DIR/issue-104088.rs:6:9
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--> $DIR/issue-104088.rs:1:4
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LL | let 1x = 123;
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LL | fn 1234test() {
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| ^^ expected identifier
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| ^^^^^^^^ expected identifier
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help: identifiers cannot start with a number
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help: identifiers cannot start with a number
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--> $DIR/issue-104088.rs:6:9
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--> $DIR/issue-104088.rs:1:4
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LL | let 1x = 123;
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LL | fn 1234test() {
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| ^
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| ^^^^
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error: expected identifier, found `2x`
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--> $DIR/issue-104088.rs:11:9
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LL | let 2x: i32 = 123;
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| ^^ expected identifier
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help: identifiers cannot start with a number
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--> $DIR/issue-104088.rs:11:9
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LL | let 2x: i32 = 123;
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| ^
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error: expected identifier, found `23name`
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error: expected identifier, found `23name`
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--> $DIR/issue-104088.rs:22:9
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--> $DIR/issue-104088.rs:9:9
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LL | let 23name = 123;
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LL | let 23name = 123;
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| ^^^^^^ expected identifier
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| ^^^^^^ expected identifier
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help: identifiers cannot start with a number
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help: identifiers cannot start with a number
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--> $DIR/issue-104088.rs:22:9
|
--> $DIR/issue-104088.rs:9:9
|
||||||
|
|
|
|
||||||
LL | let 23name = 123;
|
LL | let 23name = 123;
|
||||||
| ^^
|
| ^^
|
||||||
|
|
||||||
|
error: expected identifier, found `2x`
|
||||||
|
--> $DIR/issue-104088.rs:12:9
|
||||||
|
|
|
||||||
|
LL | let 2x: i32 = 123;
|
||||||
|
| ^^ expected identifier
|
||||||
|
|
|
||||||
|
help: identifiers cannot start with a number
|
||||||
|
--> $DIR/issue-104088.rs:12:9
|
||||||
|
|
|
||||||
|
LL | let 2x: i32 = 123;
|
||||||
|
| ^
|
||||||
|
|
||||||
|
error: expected identifier, found `1x`
|
||||||
|
--> $DIR/issue-104088.rs:15:9
|
||||||
|
|
|
||||||
|
LL | let 1x = 123;
|
||||||
|
| ^^ expected identifier
|
||||||
|
|
|
||||||
|
help: identifiers cannot start with a number
|
||||||
|
--> $DIR/issue-104088.rs:15:9
|
||||||
|
|
|
||||||
|
LL | let 1x = 123;
|
||||||
|
| ^
|
||||||
|
|
||||||
error[E0308]: mismatched types
|
error[E0308]: mismatched types
|
||||||
--> $DIR/issue-104088.rs:16:12
|
--> $DIR/issue-104088.rs:5:12
|
||||||
|
|
|
|
||||||
LL | if let 2e1 = 123 {
|
LL | if let 2e1 = 123 {
|
||||||
| ^^^ --- this expression has type `{integer}`
|
| ^^^ --- this expression has type `{integer}`
|
||||||
| |
|
| |
|
||||||
| expected integer, found floating-point number
|
| expected integer, found floating-point number
|
||||||
|
|
||||||
error: aborting due to 4 previous errors
|
error: aborting due to 5 previous errors
|
||||||
|
|
||||||
For more information about this error, try `rustc --explain E0308`.
|
For more information about this error, try `rustc --explain E0308`.
|
||||||
|
|
Loading…
Add table
Add a link
Reference in a new issue