From 2b22f5fb4398378d999db98ea270ceb415dfff22 Mon Sep 17 00:00:00 2001
From: Erlend Tobiassen <erlend.tobiassen@gmail.com>
Date: Tue, 22 Jan 2019 13:17:10 +0100
Subject: [PATCH] Optimistically bail out of where clause loop if not at start
of a type or lifetime
---
crates/ra_syntax/src/grammar/type_params.rs | 28 ++++++++++++---------
crates/ra_syntax/src/grammar/types.rs | 8 ++++++
2 files changed, 24 insertions(+), 12 deletions(-)
diff --git a/crates/ra_syntax/src/grammar/type_params.rs b/crates/ra_syntax/src/grammar/type_params.rs
index f33ec10f538..a7eacf97af0 100644
--- a/crates/ra_syntax/src/grammar/type_params.rs
+++ b/crates/ra_syntax/src/grammar/type_params.rs
@@ -105,27 +105,31 @@ pub(super) fn opt_where_clause(p: &mut Parser) {
let m = p.start();
p.bump();
- if is_where_clause_end(p) {
- // Empty where clause
- } else {
- loop {
- where_predicate(p);
+ while is_where_predicate(p) {
+ where_predicate(p);
- let comma = p.eat(COMMA);
+ let comma = p.eat(COMMA);
- if is_where_clause_end(p) {
- break;
- }
+ if is_where_clause_end(p) {
+ break;
+ }
- if !comma {
- p.error("expected comma");
- }
+ if !comma {
+ p.error("expected comma");
}
}
m.complete(p, WHERE_CLAUSE);
}
+fn is_where_predicate(p: &mut Parser) -> bool {
+ match p.current() {
+ LIFETIME => true,
+ IMPL_KW => false,
+ _ => types::is_type_start(p),
+ }
+}
+
fn is_where_clause_end(p: &mut Parser) -> bool {
p.current() == L_CURLY || p.current() == SEMI || p.current() == EQ
}
diff --git a/crates/ra_syntax/src/grammar/types.rs b/crates/ra_syntax/src/grammar/types.rs
index 21d89d83bbd..83a54c190f6 100644
--- a/crates/ra_syntax/src/grammar/types.rs
+++ b/crates/ra_syntax/src/grammar/types.rs
@@ -36,6 +36,14 @@ fn type_with_bounds_cond(p: &mut Parser, allow_bounds: bool) {
}
}
+pub(super) fn is_type_start(p: &mut Parser) -> bool {
+ match p.current() {
+ L_PAREN | EXCL | STAR | L_BRACK | AMP | UNDERSCORE | FN_KW | FOR_KW | IMPL_KW | DYN_KW
+ | L_ANGLE => true,
+ _ => paths::is_path_start(p),
+ }
+}
+
pub(super) fn ascription(p: &mut Parser) {
p.expect(COLON);
type_(p)