From 989cebc99c02acd427f01724c4fa77d81691e886 Mon Sep 17 00:00:00 2001 From: Geoffry Song Date: Fri, 15 Nov 2019 00:08:43 -0800 Subject: Fix parsing of "postfix" range expressions. Right now they are handled in `postfix_dot_expr`, but that doesn't allow it to correctly handle precedence. Integrate it more tightly with the Pratt parser instead. Also includes a drive-by fix for parsing `match .. {}`. Fixes #2242. --- crates/ra_parser/src/grammar/expressions.rs | 54 +++++++++++++---------------- 1 file changed, 24 insertions(+), 30 deletions(-) (limited to 'crates/ra_parser/src/grammar') diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs index 45f2e3de4..cf69da25a 100644 --- a/crates/ra_parser/src/grammar/expressions.rs +++ b/crates/ra_parser/src/grammar/expressions.rs @@ -290,6 +290,25 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> (Option, let m = lhs.precede(p); p.bump(op); + if is_range { + // test postfix_range + // fn foo() { + // let x = 1..; + // match 1.. { _ => () }; + // match a.b()..S { _ => () }; + // } + let has_trailing_expression = + p.at_ts(EXPR_FIRST) && !(r.forbid_structs && p.at(T!['{'])); + if !has_trailing_expression { + if op == T![..=] { + p.error("expected expression to end inclusive range"); + } + // no RHS + lhs = m.complete(p, RANGE_EXPR); + break; + } + } + expr_bp(p, r, op_bp + 1); lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR }); } @@ -330,7 +349,7 @@ fn lhs(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> if p.at(op) { m = p.start(); p.bump(op); - if p.at_ts(EXPR_FIRST) { + if p.at_ts(EXPR_FIRST) && !(r.forbid_structs && p.at(T!['{'])) { expr_bp(p, r, 2); } return Some((m.complete(p, RANGE_EXPR), BlockLike::NotBlock)); @@ -344,13 +363,7 @@ fn lhs(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> // } // let (lhs, blocklike) = atom::atom_expr(p, r)?; - return Some(postfix_expr( - p, - lhs, - blocklike, - !(r.prefer_stmt && blocklike.is_block()), - r.forbid_structs, - )); + return Some(postfix_expr(p, lhs, blocklike, !(r.prefer_stmt && blocklike.is_block()))); } }; // parse the interior of the unary expression @@ -366,7 +379,6 @@ fn postfix_expr( // `while true {break}; ();` mut block_like: BlockLike, mut allow_calls: bool, - forbid_structs: bool, ) -> (CompletedMarker, BlockLike) { loop { lhs = match p.current() { @@ -380,7 +392,7 @@ fn postfix_expr( // } T!['('] if allow_calls => call_expr(p, lhs), T!['['] if allow_calls => index_expr(p, lhs), - T![.] => match postfix_dot_expr(p, lhs, forbid_structs) { + T![.] => match postfix_dot_expr(p, lhs) { Ok(it) => it, Err(it) => { lhs = it; @@ -398,7 +410,6 @@ fn postfix_expr( fn postfix_dot_expr( p: &mut Parser, lhs: CompletedMarker, - forbid_structs: bool, ) -> Result { assert!(p.at(T![.])); if p.nth(1) == IDENT && (p.nth(2) == T!['('] || p.nth_at(2, T![::])) { @@ -418,25 +429,8 @@ fn postfix_expr( return Ok(m.complete(p, AWAIT_EXPR)); } - // test postfix_range - // fn foo() { - // let x = 1..; - // match 1.. { _ => () }; - // match a.b()..S { _ => () }; - // } - for &(op, la) in &[(T![..=], 3), (T![..], 2)] { - if p.at(op) { - let next_token = p.nth(la); - let has_trailing_expression = - !(forbid_structs && next_token == T!['{']) && EXPR_FIRST.contains(next_token); - return if has_trailing_expression { - Err(lhs) - } else { - let m = lhs.precede(p); - p.bump(op); - Ok(m.complete(p, RANGE_EXPR)) - }; - } + if p.at(T![..=]) || p.at(T![..]) { + return Err(lhs); } Ok(field_expr(p, lhs)) -- cgit v1.2.3 From a68aefdc463af054e7e98293c06b751c135911d5 Mon Sep 17 00:00:00 2001 From: Geoffry Song Date: Fri, 15 Nov 2019 01:04:37 -0800 Subject: Move inclusive range check to validation --- crates/ra_parser/src/grammar/expressions.rs | 3 --- 1 file changed, 3 deletions(-) (limited to 'crates/ra_parser/src/grammar') diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs index cf69da25a..81d4f75f9 100644 --- a/crates/ra_parser/src/grammar/expressions.rs +++ b/crates/ra_parser/src/grammar/expressions.rs @@ -300,9 +300,6 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> (Option, let has_trailing_expression = p.at_ts(EXPR_FIRST) && !(r.forbid_structs && p.at(T!['{'])); if !has_trailing_expression { - if op == T![..=] { - p.error("expected expression to end inclusive range"); - } // no RHS lhs = m.complete(p, RANGE_EXPR); break; -- cgit v1.2.3