if (!$expr instanceof Twig_Node_Expression_Constant) {
throw new Twig_Error_Syntax('An escaping strategy must be a string or a bool.', $stream->getCurrent()->getLine(), $stream->getSourceContext());
}
$value = $expr->getAttribute('value');
$compat = true === $value || false === $value;
if (true === $value) {
$value = 'html';
}
if ($compat && $stream->test(Twig_Token::NAME_TYPE)) {
@trigger_error('Using the autoescape tag with "true" or "false" before the strategy name is deprecated since version 1.21.', E_USER_DEPRECATED);
if (false === $value) {
throw new Twig_Error_Syntax('Unexpected escaping strategy as you set autoescaping to false.', $stream->getCurrent()->getLine(), $stream->getSourceContext());