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Deduplicate parse recovery code

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estebank committed Mar 29, 2019
1 parent b7dc8e7 commit 9ea6790a6444fbf65d0cba9c9518abf70077f3de
Showing with 43 additions and 35 deletions.
  1. +43 −35 src/libsyntax/parse/parser.rs
@@ -2639,11 +2639,9 @@ impl<'a> Parser<'a> {
while self.token != token::CloseDelim(token::Paren) {
es.push(match self.parse_expr() {
Ok(es) => es,
Err(mut err) => { // recover from parse error in tuple list
err.emit();
self.consume_block(token::Paren);
hi = self.prev_span;
return Ok(self.mk_expr(lo.to(hi), ExprKind::Err, ThinVec::new()));
Err(err) => {
// recover from parse error in tuple list
return Ok(self.recover_seq_parse_error(token::Paren, lo, Err(err)));
}
});
recovered = self.expect_one_of(
@@ -3254,44 +3252,54 @@ impl<'a> Parser<'a> {
}
if self.expr_is_complete(&e) { break; }
match self.token {
// expr(...)
token::OpenDelim(token::Paren) => {
match self.parse_unspanned_seq(
&token::OpenDelim(token::Paren),
&token::CloseDelim(token::Paren),
SeqSep::trailing_allowed(token::Comma),
|p| Ok(p.parse_expr()?)
) {
Ok(es) => {
// expr(...)
token::OpenDelim(token::Paren) => {
let seq = self.parse_unspanned_seq(
&token::OpenDelim(token::Paren),
&token::CloseDelim(token::Paren),
SeqSep::trailing_allowed(token::Comma),
|p| Ok(p.parse_expr()?)
).map(|es| {
let nd = self.mk_call(e, es);
hi = self.prev_span;
e = self.mk_expr(lo.to(hi), nd, ThinVec::new());
}
Err(mut err) => { // recover from parse error in argument list
err.emit();
self.consume_block(token::Paren);
hi = self.prev_span;
e = self.mk_expr(lo.to(hi), ExprKind::Err, ThinVec::new());
}
let hi = self.prev_span;
self.mk_expr(lo.to(hi), nd, ThinVec::new())
});
e = self.recover_seq_parse_error(token::Paren, lo, seq);
}
}

// expr[...]
// Could be either an index expression or a slicing expression.
token::OpenDelim(token::Bracket) => {
self.bump();
let ix = self.parse_expr()?;
hi = self.span;
self.expect(&token::CloseDelim(token::Bracket))?;
let index = self.mk_index(e, ix);
e = self.mk_expr(lo.to(hi), index, ThinVec::new())
}
_ => return Ok(e)
// expr[...]
// Could be either an index expression or a slicing expression.
token::OpenDelim(token::Bracket) => {
self.bump();
let ix = self.parse_expr()?;
hi = self.span;
self.expect(&token::CloseDelim(token::Bracket))?;
let index = self.mk_index(e, ix);
e = self.mk_expr(lo.to(hi), index, ThinVec::new())
}
_ => return Ok(e)
}
}
return Ok(e);
}

fn recover_seq_parse_error(
&mut self,
delim: token::DelimToken,
lo: Span,
result: PResult<'a, P<Expr>>,
) -> P<Expr> {
match result {
Ok(x) => x,
Err(mut err) => {
err.emit();
// recover from parse error
self.consume_block(delim);
self.mk_expr(lo.to(self.prev_span), ExprKind::Err, ThinVec::new())
}
}
}

crate fn process_potential_macro_variable(&mut self) {
let (token, span) = match self.token {
token::Dollar if self.span.ctxt() != syntax_pos::hygiene::SyntaxContext::empty() &&

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