self.sess.ambiguous_block_expr_parse.borrow_mut().insert(sp, lhs.span);
false
}
- (true, Some(AssocOp::LAnd)) => {
+ (true, Some(AssocOp::LAnd)) |
+ (true, Some(AssocOp::LOr)) |
+ (true, Some(AssocOp::BitOr)) => {
// `{ 42 } &&x` (#61475) or `{ 42 } && if x { 1 } else { 0 }`. Separated from the
// above due to #74233.
// These cases are ambiguous and can't be identified in the parser alone.
+ //
+ // Bitwise AND is left out because guessing intent is hard. We can make
+ // suggestions based on the assumption that double-refs are rarely intentional,
+ // and closures are distinct enough that they don't get mixed up with their
+ // return value.
let sp = self.sess.source_map().start_point(self.token.span);
self.sess.ambiguous_block_expr_parse.borrow_mut().insert(sp, lhs.span);
false
} else if self.check(&token::OpenDelim(token::Brace)) {
self.parse_block_expr(None, lo, BlockCheckMode::Default, attrs)
} else if self.check(&token::BinOp(token::Or)) || self.check(&token::OrOr) {
- self.parse_closure_expr(attrs)
+ self.parse_closure_expr(attrs).map_err(|mut err| {
+ // If the input is something like `if a { 1 } else { 2 } | if a { 3 } else { 4 }`
+ // then suggest parens around the lhs.
+ if let Some(sp) = self.sess.ambiguous_block_expr_parse.borrow().get(&lo) {
+ self.sess.expr_parentheses_needed(&mut err, *sp);
+ }
+ err
+ })
} else if self.check(&token::OpenDelim(token::Bracket)) {
self.parse_array_or_repeat_expr(attrs, token::Bracket)
} else if self.check_path() {