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Merge #10343

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10343: internal: parser cleanups r=matklad a=matklad

bors r+
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Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
This commit is contained in:
bors[bot] 2021-09-25 11:11:33 +00:00 committed by GitHub
commit d653995be4
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9 changed files with 142 additions and 173 deletions
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6
crates/ide_assists/src/utils/gen_trait_fn_body.rs
View File

@ -439,10 +439,10 @@ fn gen_tuple_field(field_name: &String) -> ast::Pat {
let eq_check =
make::expr_bin_op(lhs, BinaryOp::CmpOp(CmpOp::Eq { negated: false }), rhs);
let mut case_count = 0;
let mut n_cases = 0;
let mut arms = vec![];
for variant in enum_.variant_list()?.variants() {
case_count += 1;
n_cases += 1;
match variant.field_list() {
// => (Self::Bar { bin: l_bin }, Self::Bar { bin: r_bin }) => l_bin == r_bin,
Some(ast::FieldList::RecordFieldList(list)) => {
@ -517,7 +517,7 @@ fn gen_tuple_field(field_name: &String) -> ast::Pat {
let expr = match arms.len() {
0 => eq_check,
_ => {
if case_count > arms.len() {
if n_cases > arms.len() {
let lhs = make::wildcard_pat().into();
arms.push(make::match_arm(Some(lhs), None, eq_check));
}

59
crates/parser/src/grammar/expressions.rs
View File

@ -1,8 +1,9 @@
mod atom;
use super::*;
pub(crate) use self::atom::{block_expr, match_arm_list};
pub(super) use self::atom::{literal, LITERAL_FIRST};
use super::*;
pub(super) enum StmtWithSemi {
Yes,
@ -47,11 +48,6 @@ fn expr_no_struct(p: &mut Parser) {
expr_bp(p, r, 1);
}
fn is_expr_stmt_attr_allowed(kind: SyntaxKind) -> bool {
let forbid = matches!(kind, BIN_EXPR | RANGE_EXPR);
!forbid
}
pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
let m = p.start();
// test attr_on_expr_stmt
@ -79,13 +75,15 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
let (cm, blocklike) = expr_stmt(p);
let kind = cm.as_ref().map(|cm| cm.kind()).unwrap_or(ERROR);
if has_attrs && !is_expr_stmt_attr_allowed(kind) {
// test_err attr_on_expr_not_allowed
// fn foo() {
// #[A] 1 + 2;
// #[B] if true {};
// }
p.error(format!("attributes are not allowed on {:?}", kind));
if has_attrs {
if matches!(kind, BIN_EXPR | RANGE_EXPR) {
// test_err attr_on_expr_not_allowed
// fn foo() {
// #[A] 1 + 2;
// #[B] if true {};
// }
p.error(format!("attributes are not allowed on {:?}", kind));
}
}
if p.at(T!['}']) || (prefer_expr && p.at(EOF)) {
@ -117,6 +115,10 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
// }
match with_semi {
StmtWithSemi::No => (),
StmtWithSemi::Optional => {
p.eat(T![;]);
}
StmtWithSemi::Yes => {
if blocklike.is_block() {
p.eat(T![;]);
@ -124,48 +126,35 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
p.expect(T![;]);
}
}
StmtWithSemi::No => {}
StmtWithSemi::Optional => {
if p.at(T![;]) {
p.eat(T![;]);
}
}
}
m.complete(p, EXPR_STMT);
}
// test let_stmt
// fn foo() {
// let a;
// let b: i32;
// let c = 92;
// let d: i32 = 92;
// let e: !;
// let _: ! = {};
// let f = #[attr]||{};
// }
// fn f() { let x: i32 = 92; }
fn let_stmt(p: &mut Parser, m: Marker, with_semi: StmtWithSemi) {
assert!(p.at(T![let]));
p.bump(T![let]);
patterns::pattern(p);
if p.at(T![:]) {
// test let_stmt_ascription
// fn f() { let x: i32; }
types::ascription(p);
}
if p.eat(T![=]) {
// test let_stmt_init
// fn f() { let x = 92; }
expressions::expr_with_attrs(p);
}
match with_semi {
StmtWithSemi::No => (),
StmtWithSemi::Optional => {
p.eat(T![;]);
}
StmtWithSemi::Yes => {
p.expect(T![;]);
}
StmtWithSemi::No => {}
StmtWithSemi::Optional => {
if p.at(T![;]) {
p.eat(T![;]);
}
}
}
m.complete(p, LET_STMT);
}

158
crates/syntax/test_data/parser/inline/ok/0130_let_stmt.rast
View File

@ -1,127 +1,35 @@
SOURCE_FILE@0..135
FN@0..134
SOURCE_FILE@0..28
FN@0..27
FN_KW@0..2 "fn"
WHITESPACE@2..3 " "
NAME@3..6
IDENT@3..6 "foo"
PARAM_LIST@6..8
L_PAREN@6..7 "("
R_PAREN@7..8 ")"
WHITESPACE@8..9 " "
BLOCK_EXPR@9..134
L_CURLY@9..10 "{"
WHITESPACE@10..15 "\n "
LET_STMT@15..21
LET_KW@15..18 "let"
WHITESPACE@18..19 " "
IDENT_PAT@19..20
NAME@19..20
IDENT@19..20 "a"
SEMICOLON@20..21 ";"
WHITESPACE@21..26 "\n "
LET_STMT@26..37
LET_KW@26..29 "let"
WHITESPACE@29..30 " "
IDENT_PAT@30..31
NAME@30..31
IDENT@30..31 "b"
COLON@31..32 ":"
WHITESPACE@32..33 " "
PATH_TYPE@33..36
PATH@33..36
PATH_SEGMENT@33..36
NAME_REF@33..36
IDENT@33..36 "i32"
SEMICOLON@36..37 ";"
WHITESPACE@37..42 "\n "
LET_STMT@42..53
LET_KW@42..45 "let"
WHITESPACE@45..46 " "
IDENT_PAT@46..47
NAME@46..47
IDENT@46..47 "c"
WHITESPACE@47..48 " "
EQ@48..49 "="
WHITESPACE@49..50 " "
LITERAL@50..52
INT_NUMBER@50..52 "92"
SEMICOLON@52..53 ";"
WHITESPACE@53..58 "\n "
LET_STMT@58..74
LET_KW@58..61 "let"
WHITESPACE@61..62 " "
IDENT_PAT@62..63
NAME@62..63
IDENT@62..63 "d"
COLON@63..64 ":"
WHITESPACE@64..65 " "
PATH_TYPE@65..68
PATH@65..68
PATH_SEGMENT@65..68
NAME_REF@65..68
IDENT@65..68 "i32"
WHITESPACE@68..69 " "
EQ@69..70 "="
WHITESPACE@70..71 " "
LITERAL@71..73
INT_NUMBER@71..73 "92"
SEMICOLON@73..74 ";"
WHITESPACE@74..79 "\n "
LET_STMT@79..88
LET_KW@79..82 "let"
WHITESPACE@82..83 " "
IDENT_PAT@83..84
NAME@83..84
IDENT@83..84 "e"
COLON@84..85 ":"
WHITESPACE@85..86 " "
NEVER_TYPE@86..87
BANG@86..87 "!"
SEMICOLON@87..88 ";"
WHITESPACE@88..93 "\n "
LET_STMT@93..107
LET_KW@93..96 "let"
WHITESPACE@96..97 " "
WILDCARD_PAT@97..98
UNDERSCORE@97..98 "_"
COLON@98..99 ":"
WHITESPACE@99..100 " "
NEVER_TYPE@100..101
BANG@100..101 "!"
WHITESPACE@101..102 " "
EQ@102..103 "="
WHITESPACE@103..104 " "
BLOCK_EXPR@104..106
L_CURLY@104..105 "{"
R_CURLY@105..106 "}"
SEMICOLON@106..107 ";"
WHITESPACE@107..112 "\n "
LET_STMT@112..132
LET_KW@112..115 "let"
WHITESPACE@115..116 " "
IDENT_PAT@116..117
NAME@116..117
IDENT@116..117 "f"
WHITESPACE@117..118 " "
EQ@118..119 "="
WHITESPACE@119..120 " "
CLOSURE_EXPR@120..131
ATTR@120..127
POUND@120..121 "#"
L_BRACK@121..122 "["
META@122..126
PATH@122..126
PATH_SEGMENT@122..126
NAME_REF@122..126
IDENT@122..126 "attr"
R_BRACK@126..127 "]"
PARAM_LIST@127..129
PIPE@127..128 "|"
PIPE@128..129 "|"
BLOCK_EXPR@129..131
L_CURLY@129..130 "{"
R_CURLY@130..131 "}"
SEMICOLON@131..132 ";"
WHITESPACE@132..133 "\n"
R_CURLY@133..134 "}"
WHITESPACE@134..135 "\n"
NAME@3..4
IDENT@3..4 "f"
PARAM_LIST@4..6
L_PAREN@4..5 "("
R_PAREN@5..6 ")"
WHITESPACE@6..7 " "
BLOCK_EXPR@7..27
L_CURLY@7..8 "{"
WHITESPACE@8..9 " "
LET_STMT@9..25
LET_KW@9..12 "let"
WHITESPACE@12..13 " "
IDENT_PAT@13..14
NAME@13..14
IDENT@13..14 "x"
COLON@14..15 ":"
WHITESPACE@15..16 " "
PATH_TYPE@16..19
PATH@16..19
PATH_SEGMENT@16..19
NAME_REF@16..19
IDENT@16..19 "i32"
WHITESPACE@19..20 " "
EQ@20..21 "="
WHITESPACE@21..22 " "
LITERAL@22..24
INT_NUMBER@22..24 "92"
SEMICOLON@24..25 ";"
WHITESPACE@25..26 " "
R_CURLY@26..27 "}"
WHITESPACE@27..28 "\n"

10
crates/syntax/test_data/parser/inline/ok/0130_let_stmt.rs
View File

@ -1,9 +1 @@
fn foo() {
let a;
let b: i32;
let c = 92;
let d: i32 = 92;
let e: !;
let _: ! = {};
let f = #[attr]||{};
}
fn f() { let x: i32 = 92; }

28
crates/syntax/test_data/parser/inline/ok/0193_let_stmt_init.rast Normal file
View File

@ -0,0 +1,28 @@
SOURCE_FILE@0..23
FN@0..22
FN_KW@0..2 "fn"
WHITESPACE@2..3 " "
NAME@3..4
IDENT@3..4 "f"
PARAM_LIST@4..6
L_PAREN@4..5 "("
R_PAREN@5..6 ")"
WHITESPACE@6..7 " "
BLOCK_EXPR@7..22
L_CURLY@7..8 "{"
WHITESPACE@8..9 " "
LET_STMT@9..20
LET_KW@9..12 "let"
WHITESPACE@12..13 " "
IDENT_PAT@13..14
NAME@13..14
IDENT@13..14 "x"
WHITESPACE@14..15 " "
EQ@15..16 "="
WHITESPACE@16..17 " "
LITERAL@17..19
INT_NUMBER@17..19 "92"
SEMICOLON@19..20 ";"
WHITESPACE@20..21 " "
R_CURLY@21..22 "}"
WHITESPACE@22..23 "\n"

1
crates/syntax/test_data/parser/inline/ok/0193_let_stmt_init.rs Normal file
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@ -0,0 +1 @@
fn f() { let x = 92; }

30
crates/syntax/test_data/parser/inline/ok/0194_let_stmt_ascription.rast Normal file
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@ -0,0 +1,30 @@
SOURCE_FILE@0..23
FN@0..22
FN_KW@0..2 "fn"
WHITESPACE@2..3 " "
NAME@3..4
IDENT@3..4 "f"
PARAM_LIST@4..6
L_PAREN@4..5 "("
R_PAREN@5..6 ")"
WHITESPACE@6..7 " "
BLOCK_EXPR@7..22
L_CURLY@7..8 "{"
WHITESPACE@8..9 " "
LET_STMT@9..20
LET_KW@9..12 "let"
WHITESPACE@12..13 " "
IDENT_PAT@13..14
NAME@13..14
IDENT@13..14 "x"
COLON@14..15 ":"
WHITESPACE@15..16 " "
PATH_TYPE@16..19
PATH@16..19
PATH_SEGMENT@16..19
NAME_REF@16..19
IDENT@16..19 "i32"
SEMICOLON@19..20 ";"
WHITESPACE@20..21 " "
R_CURLY@21..22 "}"
WHITESPACE@22..23 "\n"

1
crates/syntax/test_data/parser/inline/ok/0194_let_stmt_ascription.rs Normal file
View File

@ -0,0 +1 @@
fn f() { let x: i32; }

22
docs/dev/style.md
View File

@ -849,7 +849,7 @@ Default names:
* `res` -- "result of the function" local variable
* `it` -- I don't really care about the name
* `n_foo` -- number of foos
* `n_foos` -- number of foos (prefer this to `foo_count`)
* `foo_idx` -- index of `foo`
Many names in rust-analyzer conflict with keywords.
@ -969,6 +969,26 @@ Don't use the `ref` keyword.
Today, it is redundant.
Between `ref` and mach ergonomics, the latter is more ergonomic in most cases, and is simpler (does not require a keyword).
## Empty Match Arms
Ues `=> (),` when a match arm is intentionally empty:
```rust
// GOOD
match result {
Ok(_) => (),
Err(err) => error!("{}", err),
}
// BAD
match result {
Ok(_) => {}
Err(err) => error!("{}", err),
}
```
**Rationale:** consistency.
## Functional Combinators
Use high order monadic combinators like `map`, `then` when they are a natural choice; don't bend the code to fit into some combinator.