Declaring annotations

Use annotations to add descriptions to types and links:

1. type Label {
2. annotation description :=
3. 'Special label to stick on reviews';
4. required property comments -> str;
5. link review -> Review {
6. annotation description :=
7. 'This review needs some attention';
8. };
9. }

Retrieving the annotations can be done via an introspection query:

1. db>
2. ...
3. ...
4. ...
5. ...
6. ...
7. ...

1. with module schema
2. select ObjectType {
3. name,
4. annotations: {name, @value},
5. links: {name, annotations: {name, @value}}
6. }
7. filter .name = 'default::Label';

1. {
2. Object {
3. name: 'default::Label',
4. annotations: {
5. Object {
6. name: 'std::description',
7. @value: 'Special label to stick on reviews'
8. }
9. },
10. links: {
11. Object {
12. name: 'review',
13. annotations: {
14. Object {
15. name: 'std::description',
16. @value: 'Special label to stick on reviews'
17. }
18. }
19. },
20. Object { name: '__type__', annotations: {} }
21. }
22. }
23. }

Alternatively, the annotations can be viewed by the following REPL command:

1. db>

1. \d+ Label

1. type default::Label {
2. annotation std::description := 'Special label to stick on reviews';
3. required single link __type__ -> schema::Type {
4. readonly := true;
5. };
6. single link review -> default::Review {
7. annotation std::description := 'Special label to stick on reviews';
8. };
9. required single property comments -> std::str;
10. required single property id -> std::uuid {
11. readonly := true;
12. constraint std::exclusive;
13. };
14. };

︙