function interpret(Context $context) { if (!is_null($this->val)) { $context->replace($this, $this->val); $this->val = null; } }
protected function doInterpret(Context $context, $result_l, $result_r) { $context->replace($this, $result_l && $result_r); }
function interpret(Context $context) { $context->replace($this, $this->value); }