perf(es/lexer): Reduce memory move (#10906)

Author: bvanjoi

crates/swc_ecma_parser/src/parser/input.rs

@@ -175,46 +175,57 @@ impl<'a, I: Tokens> swc_ecma_lexer::common::parser::buffer::Buffer<'a> for Buffe
  }
  }
 
+ #[inline(always)]
  fn set_cur(&mut self, token: TokenAndSpan) {
  self.cur = token
  }
 
+ #[inline(always)]
  fn next(&self) -> Option<&Self::Next> {
  self.next.as_ref()
  }
 
+ #[inline(always)]
  fn set_next(&mut self, token: Option<Self::Next>) {
  self.next = token;
  }
 
+ #[inline(always)]
  fn next_mut(&mut self) -> &mut Option<Self::Next> {
  &mut self.next
  }
 
+ #[inline(always)]
  fn cur(&self) -> &super::super::lexer::Token {
  &self.cur.token
  }
 
+ #[inline(always)]
  fn get_cur(&self) -> &TokenAndSpan {
  &self.cur
  }
 
+ #[inline(always)]
  fn get_cur_mut(&mut self) -> &mut TokenAndSpan {
  &mut self.cur
  }
 
+ #[inline(always)]
  fn prev_span(&self) -> Span {
  self.prev_span
  }
 
+ #[inline(always)]
  fn set_prev_span(&mut self, span: Span) {
  self.prev_span = span;
  }
 
+ #[inline(always)]
  fn iter(&self) -> &I {
  &self.iter
  }
 
+ #[inline(always)]
  fn iter_mut(&mut self) -> &mut I {
  &mut self.iter
  }
@@ -250,8 +261,8 @@ impl<'a, I: Tokens> swc_ecma_lexer::common::parser::buffer::Buffer<'a> for Buffe
  } else {
  TokenAndSpan::new(Token::Eof, self.prev_span(), true)
  };
- let prev = std::mem::replace(&mut self.cur, next);
- self.set_prev_span(prev.span());
+ self.set_prev_span(self.cur.span());
+ self.set_cur(next);
  }
 
  fn expect_word_token_and_bump(&mut self) -> Atom {