diff options
Diffstat (limited to 'src/libsyntax')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 34ed7f50907..8f8ed411180 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -3748,8 +3748,9 @@ impl<'a> Parser<'a> { }) } - /// Parse a parentesized comma separated sequence of patterns until `delim` is reached. - fn parse_recover_pat_list(&mut self) -> PResult<'a, ()> { + /// Parse and throw away a parentesized comma separated + /// sequence of patterns until `)` is reached. + fn skip_pat_list(&mut self) -> PResult<'a, ()> { while !self.check(&token::CloseDelim(token::Paren)) { self.parse_pat(None)?; if !self.eat(&token::Comma) { @@ -3772,7 +3773,7 @@ impl<'a> Parser<'a> { // later. let comma_span = self.token.span; self.bump(); - if let Err(mut err) = self.parse_recover_pat_list() { + if let Err(mut err) = self.skip_pat_list() { // We didn't expect this to work anyway; we just wanted // to advance to the end of the comma-sequence so we know // the span to suggest parenthesizing @@ -3877,9 +3878,11 @@ impl<'a> Parser<'a> { pat = PatKind::Ref(subpat, mutbl); } token::OpenDelim(token::Paren) => { - // Parse `(pat, pat, pat, ...)` as tuple pattern. + // Parse a tuple or parenthesis pattern. let (fields, trailing_comma) = self.parse_paren_comma_seq(|p| p.parse_pat(None))?; + // Here, `(pat,)` is a tuple pattern. + // For backward compatibility, `(..)` is a tuple pattern as well. pat = if fields.len() == 1 && !(trailing_comma || fields[0].is_rest()) { PatKind::Paren(fields.into_iter().nth(0).unwrap()) } else { |