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extract ban_pat_range_if_ambiguous

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This commit is contained in:
Mazdak Farrokhzad 2019-08-12 08:16:04 +02:00
parent 3b651330e0
commit 231da7e044
1 changed files with 25 additions and 20 deletions
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45
src/libsyntax/parse/parser/pat.rs
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@ -270,31 +270,36 @@ impl<'a> Parser<'a> {
let pat = self.maybe_recover_from_bad_qpath(pat, true)?;
if !allow_range_pat {
match pat.node {
PatKind::Range(
_, _, Spanned { node: RangeEnd::Included(RangeSyntax::DotDotDot), .. }
) => {},
PatKind::Range(..) => {
let mut err = self.struct_span_err(
pat.span,
"the range pattern here has ambiguous interpretation",
);
err.span_suggestion(
pat.span,
"add parentheses to clarify the precedence",
format!("({})", pprust::pat_to_string(&pat)),
// "ambiguous interpretation" implies that we have to be guessing
Applicability::MaybeIncorrect
);
return Err(err);
}
_ => {}
}
self.ban_pat_range_if_ambiguous(&pat)?
}
Ok(pat)
}
/// Ban a range pattern if it has an ambiguous interpretation.
fn ban_pat_range_if_ambiguous(&self, pat: &Pat) -> PResult<'a, ()> {
match pat.node {
PatKind::Range(
.., Spanned { node: RangeEnd::Included(RangeSyntax::DotDotDot), .. }
) => return Ok(()),
PatKind::Range(..) => {}
_ => return Ok(()),
}
let mut err = self.struct_span_err(
pat.span,
"the range pattern here has ambiguous interpretation",
);
err.span_suggestion(
pat.span,
"add parentheses to clarify the precedence",
format!("({})", pprust::pat_to_string(&pat)),
// "ambiguous interpretation" implies that we have to be guessing
Applicability::MaybeIncorrect
);
Err(err)
}
/// Parse `&pat` / `&mut pat`.
fn parse_pat_deref(&mut self, expected: Option<&'static str>) -> PResult<'a, PatKind> {
self.expect_and()?;