bjoernager/rust
bjoernager/rust
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Simplify pattern grammar by allowing nested leading vert

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Along the way, we also implement a handful of diagnostics improvements
and fixes, particularly with respect to the special handling of `||` in
place of `|` and when there are leading verts in function params, which
don't allow top-level or-patterns anyway.
This commit is contained in:
mark 2021-02-07 20:40:33 -06:00
parent d1206f950f
commit aee1e59e6f
18 changed files with 189 additions and 303 deletions
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8
compiler/rustc_parse/src/parser/expr.rs
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@ -1726,7 +1726,7 @@ impl<'a> Parser<'a> {
let lo = self.token.span;
let attrs = self.parse_outer_attributes()?;
self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
let pat = this.parse_pat(PARAM_EXPECTED)?;
let pat = this.parse_pat_no_top_alt(PARAM_EXPECTED)?;
let ty = if this.eat(&token::Colon) {
this.parse_ty()?
} else {
@ -1803,7 +1803,7 @@ impl<'a> Parser<'a> {
/// The `let` token has already been eaten.
fn parse_let_expr(&mut self, attrs: AttrVec) -> PResult<'a, P<Expr>> {
let lo = self.prev_token.span;
let pat = self.parse_top_pat(GateOr::No, RecoverComma::Yes)?;
let pat = self.parse_pat_allow_top_alt(None, GateOr::No, RecoverComma::Yes)?;
self.expect(&token::Eq)?;
let expr = self.with_res(self.restrictions | Restrictions::NO_STRUCT_LITERAL, |this| {
this.parse_assoc_expr_with(1 + prec_let_scrutinee_needs_par(), None.into())
@ -1866,7 +1866,7 @@ impl<'a> Parser<'a> {
_ => None,
};
let pat = self.parse_top_pat(GateOr::Yes, RecoverComma::Yes)?;
let pat = self.parse_pat_allow_top_alt(None, GateOr::Yes, RecoverComma::Yes)?;
if !self.eat_keyword(kw::In) {
self.error_missing_in_for_loop();
}
@ -1977,7 +1977,7 @@ impl<'a> Parser<'a> {
let attrs = self.parse_outer_attributes()?;
self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
let lo = this.token.span;
let pat = this.parse_top_pat(GateOr::No, RecoverComma::Yes)?;
let pat = this.parse_pat_allow_top_alt(None, GateOr::No, RecoverComma::Yes)?;
let guard = if this.eat_keyword(kw::If) {
let if_span = this.prev_token.span;
let cond = this.parse_expr()?;