ry/expression-language/>attribute expressions</a>. The point of these expressions is to use any attribute or literal value in order to produce a result that can be assigned to an instance’s field.</p><p>Every instance field has a type, as defined in the template, every attribute has a
<a href=https://github.com/istio/api/blob/release-1.21/policy/v1beta1/value_type.proto>type</a>, and every attribute expression has a type.
You can only assign type-compatible expressions to any given instance fields. For ex