aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_parser/src/grammar
diff options
context:
space:
mode:
authorpcpthm <[email protected]>2019-03-19 08:24:02 +0000
committerpcpthm <[email protected]>2019-03-19 08:24:02 +0000
commitffed132e52964f029a586a3efd4afc879ed39c59 (patch)
treed385c3239f92995bf56db209ab2464b50aa033d0 /crates/ra_parser/src/grammar
parent1cd18f9237b6ac48ca8461307f2a4eaf273ee394 (diff)
Allow attributes on top level expression
A top level expression is either - a expression statement or - the last expression in a block
Diffstat (limited to 'crates/ra_parser/src/grammar')
-rw-r--r--crates/ra_parser/src/grammar/expressions.rs83
-rw-r--r--crates/ra_parser/src/grammar/expressions/atom.rs4
2 files changed, 53 insertions, 34 deletions
diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index 83812e938..e35c46a5e 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -8,10 +8,10 @@ const EXPR_FIRST: TokenSet = LHS_FIRST;
8 8
9pub(super) fn expr(p: &mut Parser) -> BlockLike { 9pub(super) fn expr(p: &mut Parser) -> BlockLike {
10 let r = Restrictions { forbid_structs: false, prefer_stmt: false }; 10 let r = Restrictions { forbid_structs: false, prefer_stmt: false };
11 expr_bp(p, r, 1) 11 expr_bp(p, r, 1).1
12} 12}
13 13
14pub(super) fn expr_stmt(p: &mut Parser) -> BlockLike { 14pub(super) fn expr_stmt(p: &mut Parser) -> (Option<CompletedMarker>, BlockLike) {
15 let r = Restrictions { forbid_structs: false, prefer_stmt: true }; 15 let r = Restrictions { forbid_structs: false, prefer_stmt: true };
16 expr_bp(p, r, 1) 16 expr_bp(p, r, 1)
17} 17}
@@ -55,7 +55,13 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
55 // test block_items 55 // test block_items
56 // fn a() { fn b() {} } 56 // fn a() { fn b() {} }
57 let m = p.start(); 57 let m = p.start();
58 let has_attrs = p.at(POUND); 58 // test attr_on_expr_stmt
59 // fn foo() {
60 // #[A] foo();
61 // #[B] bar!{}
62 // #[C] #[D] {}
63 // #[D] return ();
64 // }
59 attributes::outer_attributes(p); 65 attributes::outer_attributes(p);
60 if p.at(LET_KW) { 66 if p.at(LET_KW) {
61 let_stmt(p, m); 67 let_stmt(p, m);
@@ -67,35 +73,48 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
67 Err(m) => m, 73 Err(m) => m,
68 }; 74 };
69 75
70 if has_attrs { 76 let (cm, blocklike) = expr_stmt(p);
71 m.abandon(p); 77 let cm = match cm {
72 p.error("expected a let statement or an item after attributes in block"); 78 None => {
73 } else { 79 if p.at(R_CURLY) {
74 let is_blocklike = expressions::expr_stmt(p) == BlockLike::Block; 80 m.abandon(p);
75 if p.at(R_CURLY) {
76 m.abandon(p);
77 } else {
78 // test no_semi_after_block
79 // fn foo() {
80 // if true {}
81 // loop {}
82 // match () {}
83 // while true {}
84 // for _ in () {}
85 // {}
86 // {}
87 // macro_rules! test {
88 // () => {}
89 // }
90 // test!{}
91 // }
92 if is_blocklike {
93 p.eat(SEMI);
94 } else { 81 } else {
95 p.expect(SEMI); 82 p.expect(SEMI);
83 m.complete(p, EXPR_STMT);
96 } 84 }
97 m.complete(p, EXPR_STMT); 85 continue;
86 }
87 Some(cm) => cm,
88 };
89
90 if p.at(R_CURLY) {
91 // test attr_on_last_expr_in_block
92 // fn foo() {
93 // { #[A] bar!()? }
94 // #[B] &()
95 // }
96 m.contract_child(p, cm);
97 } else {
98 // test no_semi_after_block
99 // fn foo() {
100 // if true {}
101 // loop {}
102 // match () {}
103 // while true {}
104 // for _ in () {}
105 // {}
106 // {}
107 // macro_rules! test {
108 // () => {}
109 // }
110 // test!{}
111 // }
112 if blocklike.is_block() {
113 p.eat(SEMI);
114 } else {
115 p.expect(SEMI);
98 } 116 }
117 m.complete(p, EXPR_STMT);
99 } 118 }
100 } 119 }
101 120
@@ -176,7 +195,7 @@ fn current_op(p: &Parser) -> (u8, Op) {
176} 195}
177 196
178// Parses expression with binding power of at least bp. 197// Parses expression with binding power of at least bp.
179fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike { 198fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> (Option<CompletedMarker>, BlockLike) {
180 let mut lhs = match lhs(p, r) { 199 let mut lhs = match lhs(p, r) {
181 Some((lhs, blocklike)) => { 200 Some((lhs, blocklike)) => {
182 // test stmt_bin_expr_ambiguity 201 // test stmt_bin_expr_ambiguity
@@ -185,11 +204,11 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
185 // {1} &2; 204 // {1} &2;
186 // } 205 // }
187 if r.prefer_stmt && blocklike.is_block() { 206 if r.prefer_stmt && blocklike.is_block() {
188 return BlockLike::Block; 207 return (Some(lhs), BlockLike::Block);
189 } 208 }
190 lhs 209 lhs
191 } 210 }
192 None => return BlockLike::NotBlock, 211 None => return (None, BlockLike::NotBlock),
193 }; 212 };
194 213
195 loop { 214 loop {
@@ -208,7 +227,7 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
208 expr_bp(p, r, op_bp + 1); 227 expr_bp(p, r, op_bp + 1);
209 lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR }); 228 lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR });
210 } 229 }
211 BlockLike::NotBlock 230 (Some(lhs), BlockLike::NotBlock)
212} 231}
213 232
214const LHS_FIRST: TokenSet = 233const LHS_FIRST: TokenSet =
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index d933288cd..a23977bfb 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -392,9 +392,9 @@ fn match_arm(p: &mut Parser) -> BlockLike {
392 match_guard(p); 392 match_guard(p);
393 } 393 }
394 p.expect(FAT_ARROW); 394 p.expect(FAT_ARROW);
395 let ret = expr_stmt(p); 395 let blocklike = expr_stmt(p).1;
396 m.complete(p, MATCH_ARM); 396 m.complete(p, MATCH_ARM);
397 ret 397 blocklike
398} 398}
399 399
400// test match_guard 400// test match_guard