···501501};
502502```
503503504504-In TypeScript, we expressed this as a reference to the `Post` type. Since lexicons are JSON files with globally unique names, here's how we'll say this in lexicon:
504504+So, a Like is a record that refers to its Post.
505505506506-```js {12}
507507-{
508508- "lexicon": 1,
509509- "id": "com.twitter.like",
510510- "defs": {
511511- "main": {
512512- "type": "record",
513513- "key": "tid",
514514- "record": {
515515- "type": "object",
516516- "required": ["subject"],
517517- "properties": {
518518- "subject": { "type": "ref", "ref": "com.twitter.post" }
519519- }
520520- }
521521- }
522522- }
523523-}
524524-```
506506+But how do we express this in JSON?
525507526526-We're saying: a Like is an object with a `subject` field that refers to some Post.
527527-528528-However, "refers" is doing a lot of work here. What does a Like record actually look like? How do you *actually* refer from inside of one JSON file to another JSON file?
529508530509```js
531510{
532511 subject: "???"
533512}
534513```
514514+515515+How do we refer from one JSON file to another JSON file?
535516536517We could try to refer to the Post record by its path in our "everything folder":
537518···789770 // ...
790771 "text": { "type": "string", "maxGraphemes": 300 },
791772 "createdAt": { "type": "string", "format": "datetime" },
792792- "parent": { "type": "ref", "ref": "com.twitter.post" }
773773+ "parent": { "type": "string", "format": "at-uri" }
793774 // ...
794775```
795776796796-This says: the `parent` field is a reference to another `com.twitter.post` record.
777777+This says: the `parent` field is an `at://` link to another record.
797778798779Every reply to dril's post will have dril's post as their `parent`:
799780
danabra.mov