Virtual attributes mirroring Ecto's virtual fields

Question to the Ash gurus: in the same way Ecto schemas can have virtual fields (e.g. by passing the virtual: true option, so that those fields are part of the schema/struct but not persisted to the database), does Ash have a similar concept for attributes? e.g.

attributes do
  # Core data, persisted
  attribute :title, :string

  # Virtual attribute, not persisted
  attribute :placeholder, :string, virtual: true
end

I’m very much new to Ash and learning by migrating a current project to use it (the Ash livebook tutorial is a fantastic intro, well done whoever created that!). By doing this, the benefits of the framework are becoming more obvious to me.

I’ve only run into one stumbling block which was a situation where I was using Ecto’s virtual fields. I’ve taken a look at the documentation and source code on Ash attributes and Ash.Types, but couldn’t see any obvious equivalent.

Thank you!