refactor(parser): clean up ParserState (#3345)

crates/oxc_parser/src/cursor.rs

@@ -1,6 +1,6 @@
 //! Code related to navigating `Token`s from the lexer
 
-use oxc_ast::ast::RegExpFlags;
+use oxc_ast::ast::{Decorator, RegExpFlags};
 use oxc_diagnostics::Result;
 use oxc_span::Span;
 
@@ -306,4 +306,9 @@ impl<'a> ParserImpl<'a> {
         self.ctx = ctx;
         result
     }
+
+    pub(crate) fn consume_decorators(&mut self) -> oxc_allocator::Vec<'a, Decorator<'a>> {
+        let decorators = std::mem::take(&mut self.state.decorators);
+        self.ast.new_vec_from_iter(decorators)
+    }
 }

crates/oxc_parser/src/js/class.rs

@@ -57,7 +57,7 @@ impl<'a> ParserImpl<'a> {
     ) -> Result<Box<'a, Class<'a>>> {
         self.bump_any(); // advance `class`
 
-        let decorators = self.state.consume_decorators();
+        let decorators = self.consume_decorators();
         let start_span = decorators.iter().next().map_or(start_span, |d| d.span);
 
         let id = if self.cur_kind().is_binding_identifier() && !self.at(Kind::Implements) {
@@ -360,7 +360,7 @@ impl<'a> ParserImpl<'a> {
             kind
         };
 
-        let decorators = self.state.consume_decorators();
+        let decorators = self.consume_decorators();
 
         let value = self.parse_method(r#async, generator)?;
 
@@ -444,7 +444,7 @@ impl<'a> ParserImpl<'a> {
             accessibility,
             optional,
             definite,
-            decorators: self.state.consume_decorators(),
+            decorators: self.consume_decorators(),
         };
         Ok(ClassElement::PropertyDefinition(self.ast.alloc(property_definition)))
     }
@@ -474,6 +474,7 @@ impl<'a> ParserImpl<'a> {
             AccessorPropertyType::AccessorProperty
         };
 
+        let decorators = self.consume_decorators();
         Ok(self.ast.accessor_property(
             r#type,
             self.end_span(span),
@@ -481,7 +482,7 @@ impl<'a> ParserImpl<'a> {
             value,
             computed,
             r#static,
-            self.state.consume_decorators(),
+            decorators,
         ))
     }
 }

crates/oxc_parser/src/js/list.rs

@@ -264,7 +264,7 @@ impl<'a> SeparatedList<'a> for FormalParameterList<'a> {
             }
             _ => {
                 let pattern = p.parse_binding_pattern_with_initializer()?;
-                let decorators = p.state.consume_decorators();
+                let decorators = p.consume_decorators();
                 let formal_parameter = p.ast.formal_parameter(
                     p.end_span(span),
                     pattern,

crates/oxc_parser/src/lib.rs

@@ -287,7 +287,7 @@ impl<'a> ParserImpl<'a> {
             errors: vec![],
             token: Token::default(),
             prev_token_end: 0,
-            state: ParserState::new(allocator),
+            state: ParserState::default(),
             ctx: Self::default_context(source_type, options),
             ast: AstBuilder::new(allocator),
             preserve_parens: options.preserve_parens,

crates/oxc_parser/src/state.rs

@@ -1,26 +1,10 @@
 use rustc_hash::FxHashSet;
 
-use oxc_allocator::{Allocator, Vec};
 use oxc_ast::ast::Decorator;
 
+#[derive(Default)]
 pub struct ParserState<'a> {
-    allocator: &'a Allocator,
-
     pub not_parenthesized_arrow: FxHashSet<u32>,
 
-    pub decorators: Vec<'a, Decorator<'a>>,
-}
-
-impl<'a> ParserState<'a> {
-    pub fn new(allocator: &'a Allocator) -> Self {
-        Self {
-            allocator,
-            not_parenthesized_arrow: FxHashSet::default(),
-            decorators: Vec::new_in(allocator),
-        }
-    }
-
-    pub fn consume_decorators(&mut self) -> Vec<'a, Decorator<'a>> {
-        std::mem::replace(&mut self.decorators, Vec::new_in(self.allocator))
-    }
+    pub decorators: Vec<Decorator<'a>>,
 }

crates/oxc_parser/src/ts/statement.rs

@@ -418,7 +418,7 @@ impl<'a> ParserImpl<'a> {
             return Ok(());
         }
 
-        let mut decorators = self.ast.new_vec();
+        let mut decorators = vec![];
         while self.at(Kind::At) {
             let decorator = self.parse_decorator()?;
             decorators.push(decorator);