syntax: add parser recovery for intersection- / and-patterns `p1 @ p2` Fixes https://github.com/rust-lang/rust/issues/65400. The recovery comes in two flavors: 1. We know that `p2` is a binding so we can invert as `p2 @ p1`: ```rust error: pattern on wrong side of `@` --> $DIR/intersection-patterns.rs:13:9 | LL | Some(x) @ y => {} | -------^^^- | | | | | binding on the right, should be to the left | pattern on the left, should be to the right | help: switch the order: `y @ Some(x)` ``` 2. Otherwise we emit a generic diagnostic for the lack of support for intersection patterns: ```rust error: left-hand side of `@` must be a binding --> $DIR/intersection-patterns.rs:23:9 | LL | Some(x) @ Some(y) => {} | -------^^^------- | | | | | also a pattern | interpreted as a pattern, not a binding | = note: bindings are `x`, `mut x`, `ref x`, and `ref mut x` ``` For more on and-patterns, see e.g. https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/pattern-matching#and-pattern. r? @davidtwco cc @varkor @lzutao |
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| .. | ||
| expr.rs | ||
| generics.rs | ||
| item.rs | ||
| module.rs | ||
| pat.rs | ||
| path.rs | ||
| stmt.rs | ||
| ty.rs | ||