No,
}
+/// Whether or not to recover a `:` when parsing patterns that were meant to be paths.
+#[derive(PartialEq, Copy, Clone)]
+pub enum RecoverColon {
+ Yes,
+ No,
+}
+
/// The result of `eat_or_separator`. We want to distinguish which case we are in to avoid
/// emitting duplicate diagnostics.
#[derive(Debug, Clone, Copy)]
&mut self,
expected: Expected,
rc: RecoverComma,
+ ra: RecoverColon,
) -> PResult<'a, P<Pat>> {
- self.parse_pat_allow_top_alt_inner(expected, rc).map(|(pat, _)| pat)
+ self.parse_pat_allow_top_alt_inner(expected, rc, ra).map(|(pat, _)| pat)
}
/// Returns the pattern and a bool indicating whether we recovered from a trailing vert (true =
&mut self,
expected: Expected,
rc: RecoverComma,
+ ra: RecoverColon,
) -> PResult<'a, (P<Pat>, bool)> {
// Keep track of whether we recovered from a trailing vert so that we can avoid duplicated
// suggestions (which bothers rustfix).
// If we parsed a leading `|` which should be gated,
// then we should really gate the leading `|`.
// This complicated procedure is done purely for diagnostics UX.
+ let mut first_pat = first_pat;
+
+ if let (RecoverColon::Yes, token::Colon) = (ra, &self.token.kind) {
+ if matches!(
+ first_pat.kind,
+ PatKind::Ident(BindingMode::ByValue(Mutability::Not), _, None)
+ | PatKind::Path(..)
+ ) && self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident())
+ {
+ // The pattern looks like it might be a path with a `::` -> `:` typo:
+ // `match foo { bar:baz => {} }`
+ let span = self.token.span;
+ // We only emit "unexpected `:`" error here if we can successfully parse the
+ // whole pattern correctly in that case.
+ let snapshot = self.clone();
+
+ // Create error for "unexpected `:`".
+ match self.expected_one_of_not_found(&[], &[]) {
+ Err(mut err) => {
+ self.bump(); // Skip the `:`.
+ match self.parse_pat_no_top_alt(expected) {
+ Err(mut inner_err) => {
+ // Carry on as if we had not done anything, callers will emit a
+ // reasonable error.
+ inner_err.cancel();
+ err.cancel();
+ *self = snapshot;
+ }
+ Ok(pat) => {
+ // We've parsed the rest of the pattern.
+ err.span_suggestion(
+ span,
+ "maybe write a path separator here",
+ "::".to_string(),
+ Applicability::MachineApplicable,
+ );
+ err.emit();
+ first_pat =
+ self.mk_pat(first_pat.span.to(pat.span), PatKind::Wild);
+ }
+ }
+ }
+ _ => {
+ // Carry on as if we had not done anything. This should be unreachable.
+ *self = snapshot;
+ }
+ };
+ }
+ }
+
if let Some(leading_vert_span) = leading_vert_span {
// If there was a leading vert, treat this as an or-pattern. This improves
// diagnostics.
// We use `parse_pat_allow_top_alt` regardless of whether we actually want top-level
// or-patterns so that we can detect when a user tries to use it. This allows us to print a
// better error message.
- let (pat, trailing_vert) = self.parse_pat_allow_top_alt_inner(expected, rc)?;
+ let (pat, trailing_vert) =
+ self.parse_pat_allow_top_alt_inner(expected, rc, RecoverColon::No)?;
let colon = self.eat(&token::Colon);
if let PatKind::Or(pats) = &pat.kind {
} else if self.check(&token::OpenDelim(token::Bracket)) {
// Parse `[pat, pat,...]` as a slice pattern.
let (pats, _) = self.parse_delim_comma_seq(token::Bracket, |p| {
- p.parse_pat_allow_top_alt(None, RecoverComma::No)
+ p.parse_pat_allow_top_alt(None, RecoverComma::No, RecoverColon::No)
})?;
PatKind::Slice(pats)
} else if self.check(&token::DotDot) && !self.is_pat_range_end_start(1) {
/// Parse a tuple or parenthesis pattern.
fn parse_pat_tuple_or_parens(&mut self) -> PResult<'a, PatKind> {
- let (fields, trailing_comma) =
- self.parse_paren_comma_seq(|p| p.parse_pat_allow_top_alt(None, RecoverComma::No))?;
+ let (fields, trailing_comma) = self.parse_paren_comma_seq(|p| {
+ p.parse_pat_allow_top_alt(None, RecoverComma::No, RecoverColon::No)
+ })?;
// Here, `(pat,)` is a tuple pattern.
// For backward compatibility, `(..)` is a tuple pattern as well.
} else if self.eat(&token::DotDotEq) {
RangeEnd::Included(RangeSyntax::DotDotEq)
} else if self.eat(&token::DotDot) {
- self.sess.gated_spans.gate(sym::exclusive_range_pattern, self.prev_token.span);
RangeEnd::Excluded
} else {
return None;
Some(self.parse_pat_range_end()?)
} else {
// Parsing e.g. `X..`.
- self.sess.gated_spans.gate(sym::half_open_range_patterns, begin.span.to(re.span));
if let RangeEnd::Included(_) = re.node {
// FIXME(Centril): Consider semantic errors instead in `ast_validation`.
- // Possibly also do this for `X..=` in *expression* contexts.
- self.error_inclusive_range_with_no_end(re.span);
+ self.inclusive_range_with_incorrect_end(re.span);
}
None
};
Ok(PatKind::Range(Some(begin), end, re))
}
- pub(super) fn error_inclusive_range_with_no_end(&self, span: Span) {
+ pub(super) fn inclusive_range_with_incorrect_end(&mut self, span: Span) {
+ let tok = &self.token;
+
+ // If the user typed "..==" instead of "..=", we want to give them
+ // a specific error message telling them to use "..=".
+ // Otherwise, we assume that they meant to type a half open exclusive
+ // range and give them an error telling them to do that instead.
+ if matches!(tok.kind, token::Eq) && tok.span.lo() == span.hi() {
+ let span_with_eq = span.to(tok.span);
+
+ // Ensure the user doesn't receive unhelpful unexpected token errors
+ self.bump();
+ if self.is_pat_range_end_start(0) {
+ let _ = self.parse_pat_range_end();
+ }
+
+ self.error_inclusive_range_with_extra_equals(span_with_eq);
+ } else {
+ self.error_inclusive_range_with_no_end(span);
+ }
+ }
+
+ fn error_inclusive_range_with_extra_equals(&self, span: Span) {
+ self.struct_span_err(span, "unexpected `=` after inclusive range")
+ .span_suggestion_short(
+ span,
+ "use `..=` instead",
+ "..=".to_string(),
+ Applicability::MaybeIncorrect,
+ )
+ .note("inclusive ranges end with a single equals sign (`..=`)")
+ .emit();
+ }
+
+ fn error_inclusive_range_with_no_end(&self, span: Span) {
struct_span_err!(self.sess.span_diagnostic, span, E0586, "inclusive range with no end")
.span_suggestion_short(
span,
/// Parse tuple struct or tuple variant pattern (e.g. `Foo(...)` or `Foo::Bar(...)`).
fn parse_pat_tuple_struct(&mut self, qself: Option<QSelf>, path: Path) -> PResult<'a, PatKind> {
- let (fields, _) =
- self.parse_paren_comma_seq(|p| p.parse_pat_allow_top_alt(None, RecoverComma::No))?;
+ let (fields, _) = self.parse_paren_comma_seq(|p| {
+ p.parse_pat_allow_top_alt(None, RecoverComma::No, RecoverColon::No)
+ })?;
if qself.is_some() {
self.sess.gated_spans.gate(sym::more_qualified_paths, path.span);
}
// Parsing a pattern of the form `fieldname: pat`.
let fieldname = self.parse_field_name()?;
self.bump();
- let pat = self.parse_pat_allow_top_alt(None, RecoverComma::No)?;
+ let pat = self.parse_pat_allow_top_alt(None, RecoverComma::No, RecoverColon::No)?;
hi = pat.span;
(pat, fieldname, false)
} else {
projects / rustc.git / blobdiff