Types — ASL

Types

Concrete types

A concrete type maps to a database table.

type User {
  required email: str;
  name: str;
  required age: int32;
}

The keyword model is accepted as a synonym for type.

Abstract types

Abstract types have no table of their own. They exist only to be extended by other types.

abstract type Timestamped {
  required id: uuid {
    default := gen_uuid();
    constraint pk;
  };
  required created_at: datetime { default := datetime_current(); };
  required updated_at: datetime {
    default := datetime_current();
    rewrite update := datetime_current();   # keep it fresh on every UPDATE
  };
}

default only fires on INSERT, so without the rewrite line updated_at would never change. See Rewrites.

Abstract types are meant to be reused through inheritance.