code: def _variable(lexer):
      
      names = _names(lexer)
  
      tok = next(lexer)
      # NAMES '[' ... ']'
      if isinstance(tok, LBRACK):
          indices = _indices(lexer)
          _expect_token(lexer, {RBRACK})
      # NAMES
      else:
          lexer.unpop_token(tok)
          indices = tuple()
  
      return ('var', names, indices)
docs: Return a variable expression.