or-patterns: syntax: adjust parser removing a hack.

Fuse `parse_top_pat` and `parse_top_pat_unpack` into just `parse_top_pat`.

Author: Centril

src/libsyntax/parse/parser/expr.rs

@@ -1250,8 +1250,7 @@ impl<'a> Parser<'a> {
     /// The `let` token has already been eaten.
     fn parse_let_expr(&mut self, attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let lo = self.prev_span;
-        // FIXME(or_patterns, Centril | dlrobertson): use `parse_top_pat` instead.
-        let pat = self.parse_top_pat_unpack(GateOr::No)?;
+        let pat = self.parse_top_pat(GateOr::No)?;
         self.expect(&token::Eq)?;
         let expr = self.with_res(
             Restrictions::NO_STRUCT_LITERAL,
@@ -1393,8 +1392,7 @@ impl<'a> Parser<'a> {
     crate fn parse_arm(&mut self) -> PResult<'a, Arm> {
         let attrs = self.parse_outer_attributes()?;
         let lo = self.token.span;
-        // FIXME(or_patterns, Centril | dlrobertson): use `parse_top_pat` instead.
-        let pat = self.parse_top_pat_unpack(GateOr::No)?;
+        let pat = self.parse_top_pat(GateOr::No)?;
         let guard = if self.eat_keyword(kw::If) {
             Some(self.parse_expr()?)
         } else {
@@ -1455,7 +1453,7 @@ impl<'a> Parser<'a> {
 
         Ok(ast::Arm {
             attrs,
-            pats: pat, // FIXME(or_patterns, Centril | dlrobertson): this should just be `pat,`.
+            pat,
             guard,
             body: expr,
             span: lo.to(hi),

src/libsyntax/parse/parser/pat.rs

@@ -36,16 +36,6 @@ impl<'a> Parser<'a> {
         self.parse_pat_with_range_pat(true, expected)
     }
 
-    // FIXME(or_patterns, Centril | dlrobertson):
-    // remove this and use `parse_top_pat` everywhere it is used instead.
-    pub(super) fn parse_top_pat_unpack(&mut self, gate_or: GateOr) -> PResult<'a, Vec<P<Pat>>> {
-        self.parse_top_pat(gate_or)
-            .map(|pat| pat.and_then(|pat| match pat.node {
-                PatKind::Or(pats) => pats,
-                node => vec![self.mk_pat(pat.span, node)],
-            }))
-    }
-
     /// Entry point to the main pattern parser.
     /// Corresponds to `top_pat` in RFC 2535 and allows or-pattern at the top level.
     pub(super) fn parse_top_pat(&mut self, gate_or: GateOr) -> PResult<'a, P<Pat>> {