bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Rollup merge of #81869 - mark-i-m:leading-vert, r=petrochenkov

Browse source 
Simplify pattern grammar, improve or-pattern diagnostics

This implements the change under FCP in https://github.com/rust-lang/rust/issues/81415. It allows nested or-patterns to contain a leading `|`, simplifying the [grammar for patterns](https://github.com/rust-lang/reference/pull/957/files?short_path=cc629f1#diff-cc629f15712821139bc706c63b3845ab59a008e2a998e08ffad42e3aebcbcbe2).

Along the way, we also improve the diagnostics around a few specially-handled cases, such as using `||` instead of `|`, using or-patterns in fn params, including the leading `|` in the pattern span, etc.

r? `@petrochenkov`
This commit is contained in:
Dylan DPC 2021-02-17 23:51:16 +01:00 • committed by GitHub
commit 91e5384fc0
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
18 changed files with 189 additions and 303 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_expand/src/expand.rs
View file

@ -22,7 +22,7 @@ use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_data_structures::sync::Lrc;
use rustc_errors::{Applicability, PResult};
use rustc_feature::Features;
use rustc_parse::parser::{AttemptLocalParseRecovery, ForceCollect, Parser};
use rustc_parse::parser::{AttemptLocalParseRecovery, ForceCollect, GateOr, Parser, RecoverComma};
use rustc_parse::validate_attr;
use rustc_session::lint::builtin::UNUSED_DOC_COMMENTS;
use rustc_session::lint::BuiltinLintDiagnostics;
@ -914,7 +914,9 @@ pub fn parse_ast_fragment<'a>(
}
}
AstFragmentKind::Ty => AstFragment::Ty(this.parse_ty()?),
AstFragmentKind::Pat => AstFragment::Pat(this.parse_pat(None)?),
AstFragmentKind::Pat => {
AstFragment::Pat(this.parse_pat_allow_top_alt(None, GateOr::Yes, RecoverComma::No)?)
}
AstFragmentKind::Arms
| AstFragmentKind::Fields
| AstFragmentKind::FieldPats