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Improve parsing of incomplete field accesses in preparation for field completion

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We need to be able to get the receiver even if there is no field name yet, and
currently "a." wouldn't get parsed as a field name at all. This seems to help.
This commit is contained in:
Florian Diebold 2018-12-25 14:48:54 +01:00
parent 55c941cd9f
commit 0d724ea572
3 changed files with 45 additions and 9 deletions
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16
crates/ra_syntax/src/grammar/expressions.rs
View file

@ -283,14 +283,10 @@ fn postfix_expr(
// }
L_PAREN if allow_calls => call_expr(p, lhs),
L_BRACK if allow_calls => index_expr(p, lhs),
DOT if p.nth(1) == IDENT => {
if p.nth(2) == L_PAREN || p.nth(2) == COLONCOLON {
method_call_expr(p, lhs)
} else {
field_expr(p, lhs)
}
DOT if p.nth(1) == IDENT && (p.nth(2) == L_PAREN || p.nth(2) == COLONCOLON) => {
method_call_expr(p, lhs)
}
DOT if p.nth(1) == INT_NUMBER => field_expr(p, lhs),
DOT => field_expr(p, lhs),
// test postfix_range
// fn foo() { let x = 1..; }
DOTDOT | DOTDOTEQ if !EXPR_FIRST.contains(p.nth(1)) => {
@ -355,13 +351,15 @@ fn method_call_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
// x.0.bar;
// }
fn field_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
assert!(p.at(DOT) && (p.nth(1) == IDENT || p.nth(1) == INT_NUMBER));
assert!(p.at(DOT));
let m = lhs.precede(p);
p.bump();
if p.at(IDENT) {
name_ref(p)
} else {
} else if p.at(INT_NUMBER) {
p.bump()
} else {
p.error("expected field name or number")
}
m.complete(p, FIELD_EXPR)
}

3
crates/ra_syntax/tests/data/parser/err/0029_field_completion.rs Normal file
View file

@ -0,0 +1,3 @@
fn foo(a: A) {
a.
}

35
crates/ra_syntax/tests/data/parser/err/0029_field_completion.txt Normal file
View file

@ -0,0 +1,35 @@
SOURCE_FILE@[0; 24)
FN_DEF@[0; 23)
FN_KW@[0; 2)
WHITESPACE@[2; 3)
NAME@[3; 6)
IDENT@[3; 6) "foo"
PARAM_LIST@[6; 12)
L_PAREN@[6; 7)
PARAM@[7; 11)
BIND_PAT@[7; 8)
NAME@[7; 8)
IDENT@[7; 8) "a"
COLON@[8; 9)
WHITESPACE@[9; 10)
PATH_TYPE@[10; 11)
PATH@[10; 11)
PATH_SEGMENT@[10; 11)
NAME_REF@[10; 11)
IDENT@[10; 11) "A"
R_PAREN@[11; 12)
WHITESPACE@[12; 13)
BLOCK@[13; 23)
L_CURLY@[13; 14)
WHITESPACE@[14; 19)
FIELD_EXPR@[19; 21)
PATH_EXPR@[19; 20)
PATH@[19; 20)
PATH_SEGMENT@[19; 20)
NAME_REF@[19; 20)
IDENT@[19; 20) "a"
DOT@[20; 21)
err: `expected field name or number`
WHITESPACE@[21; 22)
R_CURLY@[22; 23)
WHITESPACE@[23; 24)