fix(es/parser): Revert lexer fix for << (#7807)

This temporarily reverts commit 6850372
until #7621 can be fixed.

Re-opens #7187.

Author: dsherret

crates/swc_ecma_parser/src/lexer/state.rs

@@ -189,10 +189,6 @@ impl Tokens for Lexer<'_> {
     fn take_errors(&mut self) -> Vec<Error> {
         take(&mut self.errors.borrow_mut())
     }
-
-    fn reset_to(&mut self, to: BytePos) {
-        self.input.reset_to(to);
-    }
 }
 
 impl<'a> Iterator for Lexer<'a> {

crates/swc_ecma_parser/src/macros.rs

@@ -113,9 +113,6 @@ macro_rules! tok {
     ('>') => {
         crate::token::Token::BinOp(crate::token::BinOpToken::Gt)
     };
-    ("<<") => {
-        crate::token::Token::BinOp(crate::token::BinOpToken::LShift)
-    };
     (">>") => {
         crate::token::Token::BinOp(crate::token::BinOpToken::RShift)
     };

crates/swc_ecma_parser/src/parser/expr.rs

@@ -688,12 +688,11 @@ impl<I: Tokens> Parser<I> {
         let obj = self.parse_primary_expr()?;
         return_if_arrow!(self, obj);
 
-        let type_args = if self.syntax().typescript() {
+        let type_args = if self.syntax().typescript() && is!(self, '<') {
             self.try_parse_ts_type_args()
         } else {
             None
         };
-
         let obj = if let Some(type_args) = type_args {
             trace_cur!(self, parse_member_expr_or_new_expr__with_type_args);
             Box::new(Expr::TsInstantiation(TsInstantiation {
@@ -1621,27 +1620,9 @@ impl<I: Tokens> Parser<I> {
         let callee = self.parse_new_expr()?;
         return_if_arrow!(self, callee);
 
-        let type_args = if self.input.syntax().typescript() && is_one_of!(self, '<', "<<") {
-            let type_args_start = self.input.cur_pos();
+        let type_args = if self.input.syntax().typescript() && is!(self, '<') {
             self.try_parse_ts(|p| {
-                trace_cur!(p, parse_lhs_expr__type_args);
-
-                if is!(p, "<<") {
-                    let ctx = Context {
-                        should_not_lex_lt_or_gt_as_type: false,
-                        in_type: true,
-                        ..p.ctx()
-                    };
-                    p.input.reset_to(type_args_start);
-                    p.input.set_ctx(ctx);
-                }
-
-                trace_cur!(p, parse_lhs_expr__before_type_args);
-
                 let type_args = p.parse_ts_type_args()?;
-
-                trace_cur!(p, parse_lhs_expr__after_type_args);
-
                 if is!(p, '(') {
                     Ok(Some(type_args))
                 } else {

crates/swc_ecma_parser/src/parser/input.rs

@@ -46,8 +46,6 @@ pub trait Tokens: Clone + Iterator<Item = TokenAndSpan> {
     fn add_module_mode_error(&self, error: Error);
 
     fn take_errors(&mut self) -> Vec<Error>;
-
-    fn reset_to(&mut self, to: BytePos);
 }
 
 #[derive(Clone)]
@@ -143,8 +141,6 @@ impl Tokens for TokensInput {
     fn take_errors(&mut self) -> Vec<Error> {
         take(&mut self.errors.borrow_mut())
     }
-
-    fn reset_to(&mut self, _: BytePos) {}
 }
 
 /// Note: Lexer need access to parser's context to lex correctly.
@@ -257,10 +253,6 @@ impl<I: Tokens> Tokens for Capturing<I> {
     fn take_errors(&mut self) -> Vec<Error> {
         self.inner.take_errors()
     }
-
-    fn reset_to(&mut self, to: BytePos) {
-        self.inner.reset_to(to);
-    }
 }
 
 /// This struct is responsible for managing current token and peeked token.
@@ -326,9 +318,9 @@ impl<I: Tokens> Buffer<I> {
 
     #[cold]
     #[inline(never)]
-    pub fn dump_cur(&self) -> String {
-        match &self.cur {
-            Some(v) => format!("{:?}", v.token),
+    pub fn dump_cur(&mut self) -> String {
+        match self.cur() {
+            Some(v) => format!("{:?}", v),
             None => "<eof>".to_string(),
         }
     }
@@ -502,10 +494,4 @@ impl<I: Tokens> Buffer<I> {
     pub(crate) fn set_token_context(&mut self, c: lexer::TokenContexts) {
         self.iter.set_token_context(c)
     }
-
-    #[inline]
-    pub(crate) fn reset_to(&mut self, to: BytePos) {
-        self.cur = None;
-        self.iter.reset_to(to)
-    }
 }

crates/swc_ecma_parser/src/parser/typescript.rs

@@ -461,9 +461,7 @@ impl<I: Tokens> Parser<I> {
         permit_in_out: bool,
         permit_const: bool,
     ) -> PResult<Box<TsTypeParamDecl>> {
-        trace_cur!(self, parse_ts_type_params);
-
-        let ret = self.in_type().parse_with(|p| {
+        self.in_type().parse_with(|p| {
             p.ts_in_no_context(|p| {
                 let start = cur_pos!(p);
 
@@ -485,11 +483,7 @@ impl<I: Tokens> Parser<I> {
                     params,
                 }))
             })
-        })?;
-
-        trace_cur!(self, parse_ts_type_params__end);
-
-        Ok(ret)
+        })
     }
 
     /// `tsParseTypeOrTypePredicateAnnotation`
@@ -585,25 +579,11 @@ impl<I: Tokens> Parser<I> {
 
     #[cfg_attr(feature = "debug", tracing::instrument(skip_all))]
     pub(super) fn try_parse_ts_type_args(&mut self) -> Option<Box<TsTypeParamInstantiation>> {
-        let start = self.input.cur_pos();
-
         trace_cur!(self, try_parse_ts_type_args);
         debug_assert!(self.input.syntax().typescript());
 
         self.try_parse_ts(|p| {
-            let nested = is!(p, "<<");
-            if nested {
-                let ctx = Context {
-                    should_not_lex_lt_or_gt_as_type: false,
-                    in_type: true,
-                    ..p.ctx()
-                };
-                p.input.reset_to(start);
-                p.input.set_ctx(ctx);
-            }
-
             let type_args = p.parse_ts_type_args()?;
-            trace_cur!(p, try_parse_ts_type_args__after_type_args);
 
             if is_one_of!(
                 p, '<', // invalid syntax
@@ -1865,12 +1845,9 @@ impl<I: Tokens> Parser<I> {
 
         // ----- inlined `self.tsFillSignature(tt.arrow, node)`
         let type_params = self.try_parse_ts_type_params(false, true)?;
-        trace_cur!(self, parse_ts_fn_or_constructor_type__after_type_params);
         expect!(self, '(');
         let params = self.parse_ts_binding_list_for_signature()?;
-        trace_cur!(self, parse_ts_fn_or_constructor_type__after_params);
         let type_ann = self.parse_ts_type_or_type_predicate_ann(&tok!("=>"))?;
-        trace_cur!(self, parse_ts_fn_or_constructor_type__after_type_ann);
         // ----- end
 
         Ok(if is_fn_type {
@@ -2038,8 +2015,6 @@ impl<I: Tokens> Parser<I> {
         permit_in_out: bool,
         permit_const: bool,
     ) -> PResult<Option<Box<TsTypeParamDecl>>> {
-        trace_cur!(self, try_parse_ts_type_params);
-
         if !cfg!(feature = "typescript") {
             return Ok(None);
         }