Merge #1848

1848: Parse `..` as a full pattern r=matklad a=ecstatic-morse

Resolves #1479.

This PR implements [RFC 2707](https://github.com/rust-lang/rfcs/pull/2707) in the parser. It introduces a new `DotDotPat` AST node modeled on `PlaceholderPat` and changes the parsing of tuple and slice patterns to conform to the RFC.

Notably, this PR does *not* change the resulting AST when `..` appears in a struct pattern (e.g. `Struct { a, b: c, .. }`). I *think* this is the behavior mandated by RFC 2707, but someone should confirm this.

Co-authored-by: Dylan MacKenzie <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/crates/ra_hir/src/expr/lower.rs b/crates/ra_hir/src/expr/lower.rs
index 2be6f5421..61535d24f 100644
--- a/crates/ra_hir/src/expr/lower.rs
+++ b/crates/ra_hir/src/expr/lower.rs
@@ -573,6 +573,7 @@ where
             }
 
             // FIXME: implement
+            ast::Pat::DotDotPat(_) => Pat::Missing,
             ast::Pat::BoxPat(_) => Pat::Missing,
             ast::Pat::LiteralPat(_) => Pat::Missing,
             ast::Pat::SlicePat(_) | ast::Pat::RangePat(_) => Pat::Missing,