Unnamed repository; edit this file 'description' to name the repository.
Auto merge of #16786 - pksunkara:improve-readability, r=lnicola
internal: Improve readability of the parser code
The code is basically equivalent to the previous version, but it improves the readability by making it much more simpler and concise.
| -rw-r--r-- | crates/parser/src/grammar.rs | 4 | ||||
| -rw-r--r-- | crates/parser/src/grammar/expressions.rs | 14 | ||||
| -rw-r--r-- | crates/parser/src/grammar/expressions/atom.rs | 5 | ||||
| -rw-r--r-- | crates/parser/src/grammar/generic_params.rs | 2 | ||||
| -rw-r--r-- | crates/parser/src/grammar/items.rs | 42 | ||||
| -rw-r--r-- | crates/parser/src/grammar/items/traits.rs | 6 | ||||
| -rw-r--r-- | crates/parser/src/grammar/params.rs | 7 | ||||
| -rw-r--r-- | crates/parser/src/grammar/patterns.rs | 8 | ||||
| -rw-r--r-- | crates/parser/src/grammar/types.rs | 6 | ||||
| -rw-r--r-- | crates/parser/src/parser.rs | 9 |
10 files changed, 39 insertions, 64 deletions
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs index 456fd7ea2d..4e5837312f 100644 --- a/crates/parser/src/grammar.rs +++ b/crates/parser/src/grammar.rs @@ -416,14 +416,12 @@ fn delimited( if !parser(p) { break; } - if !p.at(delim) { + if !p.eat(delim) { if p.at_ts(first_set) { p.error(format!("expected {:?}", delim)); } else { break; } - } else { - p.bump(delim); } } p.expect(ket); diff --git a/crates/parser/src/grammar/expressions.rs b/crates/parser/src/grammar/expressions.rs index 6b660180f8..861fcedda2 100644 --- a/crates/parser/src/grammar/expressions.rs +++ b/crates/parser/src/grammar/expressions.rs @@ -211,9 +211,8 @@ fn current_op(p: &Parser<'_>) -> (u8, SyntaxKind, Associativity) { T![>] if p.at(T![>>]) => (9, T![>>], Left), T![>] if p.at(T![>=]) => (5, T![>=], Left), T![>] => (5, T![>], Left), - T![=] if p.at(T![=>]) => NOT_AN_OP, T![=] if p.at(T![==]) => (5, T![==], Left), - T![=] => (1, T![=], Right), + T![=] if !p.at(T![=>]) => (1, T![=], Right), T![<] if p.at(T![<=]) => (5, T![<=], Left), T![<] if p.at(T![<<=]) => (1, T![<<=], Right), T![<] if p.at(T![<<]) => (9, T![<<], Left), @@ -247,7 +246,7 @@ fn current_op(p: &Parser<'_>) -> (u8, SyntaxKind, Associativity) { fn expr_bp( p: &mut Parser<'_>, m: Option<Marker>, - mut r: Restrictions, + r: Restrictions, bp: u8, ) -> Option<(CompletedMarker, BlockLike)> { let m = m.unwrap_or_else(|| { @@ -295,10 +294,6 @@ fn expr_bp( let m = lhs.precede(p); p.bump(op); - // test binop_resets_statementness - // fn f() { v = {1}&2; } - r = Restrictions { prefer_stmt: false, ..r }; - if is_range { // test postfix_range // fn foo() { @@ -319,6 +314,9 @@ fn expr_bp( Associativity::Left => op_bp + 1, Associativity::Right => op_bp, }; + + // test binop_resets_statementness + // fn f() { v = {1}&2; } expr_bp(p, None, Restrictions { prefer_stmt: false, ..r }, op_bp); lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR }); } @@ -345,7 +343,7 @@ fn lhs(p: &mut Parser<'_>, r: Restrictions) -> Option<(CompletedMarker, BlockLik T![&] => { m = p.start(); p.bump(T![&]); - if p.at_contextual_kw(T![raw]) && (p.nth_at(1, T![mut]) || p.nth_at(1, T![const])) { + if p.at_contextual_kw(T![raw]) && [T![mut], T![const]].contains(&p.nth(1)) { p.bump_remap(T![raw]); p.bump_any(); } else { diff --git a/crates/parser/src/grammar/expressions/atom.rs b/crates/parser/src/grammar/expressions/atom.rs index 48600641ad..72848a1f2b 100644 --- a/crates/parser/src/grammar/expressions/atom.rs +++ b/crates/parser/src/grammar/expressions/atom.rs @@ -147,7 +147,7 @@ pub(super) fn atom_expr( T![async] if la == T![move] && p.nth(2) == T!['{'] => { let m = p.start(); p.bump(T![async]); - p.eat(T![move]); + p.bump(T![move]); stmt_list(p); m.complete(p, BLOCK_EXPR) } @@ -390,8 +390,7 @@ fn if_expr(p: &mut Parser<'_>) -> CompletedMarker { p.bump(T![if]); expr_no_struct(p); block_expr(p); - if p.at(T![else]) { - p.bump(T![else]); + if p.eat(T![else]) { if p.at(T![if]) { if_expr(p); } else { diff --git a/crates/parser/src/grammar/generic_params.rs b/crates/parser/src/grammar/generic_params.rs index 4498daf21a..6c05abc023 100644 --- a/crates/parser/src/grammar/generic_params.rs +++ b/crates/parser/src/grammar/generic_params.rs @@ -170,7 +170,7 @@ fn type_bound(p: &mut Parser<'_>) -> bool { _ => (), } if paths::is_use_path_start(p) { - types::path_type_(p, false); + types::path_type_bounds(p, false); } else { m.abandon(p); return false; diff --git a/crates/parser/src/grammar/items.rs b/crates/parser/src/grammar/items.rs index 243a219525..ee11571307 100644 --- a/crates/parser/src/grammar/items.rs +++ b/crates/parser/src/grammar/items.rs @@ -156,27 +156,19 @@ pub(super) fn opt_item(p: &mut Parser<'_>, m: Marker) -> Result<(), Marker> { // impl T for Foo { // default async fn foo() {} // } - T![async] => { - let mut maybe_fn = p.nth(2); - let is_unsafe = if matches!(maybe_fn, T![unsafe]) { - // test default_async_unsafe_fn - // impl T for Foo { - // default async unsafe fn foo() {} - // } - maybe_fn = p.nth(3); - true - } else { - false - }; - - if matches!(maybe_fn, T![fn]) { - p.bump_remap(T![default]); - p.bump(T![async]); - if is_unsafe { - p.bump(T![unsafe]); - } - has_mods = true; - } + T![async] + if p.nth_at(2, T![fn]) || (p.nth_at(2, T![unsafe]) && p.nth_at(3, T![fn])) => + { + p.bump_remap(T![default]); + p.bump(T![async]); + + // test default_async_unsafe_fn + // impl T for Foo { + // default async unsafe fn foo() {} + // } + p.eat(T![unsafe]); + + has_mods = true; } _ => (), } @@ -419,11 +411,9 @@ fn fn_(p: &mut Parser<'_>, m: Marker) { // fn foo<T>() where T: Copy {} generic_params::opt_where_clause(p); - if p.at(T![;]) { - // test fn_decl - // trait T { fn foo(); } - p.bump(T![;]); - } else { + // test fn_decl + // trait T { fn foo(); } + if !p.eat(T![;]) { expressions::block_expr(p); } m.complete(p, FN); diff --git a/crates/parser/src/grammar/items/traits.rs b/crates/parser/src/grammar/items/traits.rs index a8a1ccb15e..c215185d63 100644 --- a/crates/parser/src/grammar/items/traits.rs +++ b/crates/parser/src/grammar/items/traits.rs @@ -119,11 +119,11 @@ fn not_a_qualified_path(p: &Parser<'_>) -> bool { // we disambiguate it in favor of generics (`impl<T> ::absolute::Path<T> { ... }`) // because this is what almost always expected in practice, qualified paths in impls // (`impl <Type>::AssocTy { ... }`) aren't even allowed by type checker at the moment. - if p.nth(1) == T![#] || p.nth(1) == T![>] || p.nth(1) == T![const] { + if [T![#], T![>], T![const]].contains(&p.nth(1)) { return true; } - (p.nth(1) == LIFETIME_IDENT || p.nth(1) == IDENT) - && (p.nth(2) == T![>] || p.nth(2) == T![,] || p.nth(2) == T![:] || p.nth(2) == T![=]) + ([LIFETIME_IDENT, IDENT].contains(&p.nth(1))) + && ([T![>], T![,], T![:], T![=]].contains(&p.nth(2))) } // test_err impl_type diff --git a/crates/parser/src/grammar/params.rs b/crates/parser/src/grammar/params.rs index 846da28cb0..c535267c16 100644 --- a/crates/parser/src/grammar/params.rs +++ b/crates/parser/src/grammar/params.rs @@ -76,19 +76,16 @@ fn list_(p: &mut Parser<'_>, flavor: Flavor) { m.abandon(p); if p.eat(T![,]) { continue; - } else { - break; } + break; } param(p, m, flavor); - if !p.at(T![,]) { + if !p.eat(T![,]) { if p.at_ts(PARAM_FIRST.union(ATTRIBUTE_FIRST)) { p.error("expected `,`"); } else { break; } - } else { - p.bump(T![,]); } } diff --git a/crates/parser/src/grammar/patterns.rs b/crates/parser/src/grammar/patterns.rs index 5036742337..eff6b66404 100644 --- a/crates/parser/src/grammar/patterns.rs +++ b/crates/parser/src/grammar/patterns.rs @@ -255,9 +255,7 @@ fn is_literal_pat_start(p: &Parser<'_>) -> bool { fn literal_pat(p: &mut Parser<'_>) -> CompletedMarker { assert!(is_literal_pat_start(p)); let m = p.start(); - if p.at(T![-]) { - p.bump(T![-]); - } + p.eat(T![-]); expressions::literal(p); m.complete(p, LITERAL_PAT) } @@ -468,14 +466,12 @@ fn slice_pat(p: &mut Parser<'_>) -> CompletedMarker { fn pat_list(p: &mut Parser<'_>, ket: SyntaxKind) { while !p.at(EOF) && !p.at(ket) { pattern_top(p); - if !p.at(T![,]) { + if !p.eat(T![,]) { if p.at_ts(PAT_TOP_FIRST) { p.error(format!("expected {:?}, got {:?}", T![,], p.current())); } else { break; } - } else { - p.bump(T![,]); } } } diff --git a/crates/parser/src/grammar/types.rs b/crates/parser/src/grammar/types.rs index 96a6cdeaaf..18ec570cd5 100644 --- a/crates/parser/src/grammar/types.rs +++ b/crates/parser/src/grammar/types.rs @@ -48,7 +48,7 @@ fn type_with_bounds_cond(p: &mut Parser<'_>, allow_bounds: bool) { T![impl] => impl_trait_type(p), T![dyn] => dyn_trait_type(p), // Some path types are not allowed to have bounds (no plus) - T![<] => path_type_(p, allow_bounds), + T![<] => path_type_bounds(p, allow_bounds), _ if paths::is_path_start(p) => path_or_macro_type_(p, allow_bounds), LIFETIME_IDENT if p.nth_at(1, T![+]) => bare_dyn_trait_type(p), _ => { @@ -294,7 +294,7 @@ fn bare_dyn_trait_type(p: &mut Parser<'_>) { // type C = self::Foo; // type D = super::Foo; pub(super) fn path_type(p: &mut Parser<'_>) { - path_type_(p, true); + path_type_bounds(p, true); } // test macro_call_type @@ -323,7 +323,7 @@ fn path_or_macro_type_(p: &mut Parser<'_>, allow_bounds: bool) { } } -pub(super) fn path_type_(p: &mut Parser<'_>, allow_bounds: bool) { +pub(super) fn path_type_bounds(p: &mut Parser<'_>, allow_bounds: bool) { assert!(paths::is_path_start(p)); let m = p.start(); paths::type_path(p); diff --git a/crates/parser/src/parser.rs b/crates/parser/src/parser.rs index ef413c6375..051461243a 100644 --- a/crates/parser/src/parser.rs +++ b/crates/parser/src/parser.rs @@ -250,12 +250,9 @@ impl<'t> Parser<'t> { /// Create an error node and consume the next token. pub(crate) fn err_recover(&mut self, message: &str, recovery: TokenSet) { - match self.current() { - T!['{'] | T!['}'] => { - self.error(message); - return; - } - _ => (), + if matches!(self.current(), T!['{'] | T!['}']) { + self.error(message); + return; } if self.at_ts(recovery) { |