JSON data is also a valid Prolog term, and the declarative programming language Prolog is ideally suited for handling tree-shaped data. Using for example Scrye

JSON data is also a valid Prolog term, and the declarative programming language Prolog is ideally suited for handling tree-shaped data. Using for example Scryer Prolog, we can conveniently relate the data to a flat list of items with Prolog's built-in grammar mechanism, definite clause grammars (DCGs): flat_json(JSON) --> { JSON = {A,B,C,D,E,F,_:Cs} }, [{A,B,C,D,E,F}], flat_items(Cs). flat_items([]) --> []. flat_items([I|Is]) --> { I = {(A,B,C,D,E,_:Cs)} }, [{A,B,C,D,E}], flat_items(Cs), flat_items(Is). Sample query, using the example JSON data from the article: ?- JSON = { "id": 27941108, "created_at": "2021-07-24T14:15:05.000Z", "type": "story", "author": "edward", "title": "Fun with Unix domain sockets", "url": "https://simonwillison.net/2021/Jul/13/unix-domain-sockets/", "children": [ { "id": 27942287, "created_at": "2021-07-24T16:31:18.000Z", "type": "comment", "author": "DesiLurker", "text": "<p>one lesser known...", "children": [] }, { "id": 27944615, "created_at": "2021-07-24T21:26:33.000Z", "type": "comment", "author": "galaxyLogic", "text": "<p>I read this from Wikipedia...", "children": [ { "id": 27944746, "created_at": "2021-07-24T21:49:07.000Z", "type": "comment", "author": "hughrr", "text": "<p>Yes although I ...", "children": [] } ] } ] }, phrase(flat_json(JSON), Cs), maplist(portray_clause, Cs). yielding the flat list of entries, as desired: [{("id":27941108,"created_at":"2021-07-24T14:15:05.000Z","type":"story","author":"edward",...)}, {("id":27942287,"created_at":"2021-07-24T16:31:18.000Z","type":"comment",...)}, {("id":27944615,"created_at":"2021-07-24T21:26:33.000Z","type":"comment",...)}, {("id":27944746,"created_at":"2021-07-24T21:49:07.000Z","type":"comment",...)}]