{"action":"created","issue":{"url":"https://api.github.com/repos/firebase/bolt/issues/35","labels_url":"https://api.github.com/repos/firebase/bolt/issues/35/labels{/name}","comments_url":"https://api.github.com/repos/firebase/bolt/issues/35/comments","events_url":"https://api.github.com/repos/firebase/bolt/issues/35/events","html_url":"https://github.com/firebase/bolt/issues/35","id":105054108,"number":35,"title":"Replace 'data' with 'prior(this)'","user":{"login":"mckoss","id":82750,"avatar_url":"https://avatars.githubusercontent.com/u/82750?v=3","gravatar_id":"","url":"https://api.github.com/users/mckoss","html_url":"https://github.com/mckoss","followers_url":"https://api.github.com/users/mckoss/followers","following_url":"https://api.github.com/users/mckoss/following{/other_user}","gists_url":"https://api.github.com/users/mckoss/gists{/gist_id}","starred_url":"https://api.github.com/users/mckoss/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mckoss/subscriptions","organizations_url":"https://api.github.com/users/mckoss/orgs","repos_url":"https://api.github.com/users/mckoss/repos","events_url":"https://api.github.com/users/mckoss/events{/privacy}","received_events_url":"https://api.github.com/users/mckoss/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/firebase/bolt/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-09-05T22:42:43Z","updated_at":"2015-09-06T08:19:03Z","closed_at":null,"body":"It's odd to have a \"global\" symbol represent the prior state of a data element.\r\n\r\nI propose instead to offer a built-in-function, prior(), that we return the previous value of a datum (one referenced via this).\r\n\r\n    'prior(this.prop)' => data.prop\r\n\r\nNote how you can then write:\r\n\r\n    function nonDecreasing(n) { return prior(n) == null || n > prior(n); }\r\n    path /x { write() { return nonDecreasing(this.counter);  }\r\n\r\n@tomlarkworthy @matjaz @TristonianJones - Comments?\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/firebase/bolt/issues/comments/138051893","html_url":"https://github.com/firebase/bolt/issues/35#issuecomment-138051893","issue_url":"https://api.github.com/repos/firebase/bolt/issues/35","id":138051893,"user":{"login":"matjaz","id":10425,"avatar_url":"https://avatars.githubusercontent.com/u/10425?v=3","gravatar_id":"","url":"https://api.github.com/users/matjaz","html_url":"https://github.com/matjaz","followers_url":"https://api.github.com/users/matjaz/followers","following_url":"https://api.github.com/users/matjaz/following{/other_user}","gists_url":"https://api.github.com/users/matjaz/gists{/gist_id}","starred_url":"https://api.github.com/users/matjaz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/matjaz/subscriptions","organizations_url":"https://api.github.com/users/matjaz/orgs","repos_url":"https://api.github.com/users/matjaz/repos","events_url":"https://api.github.com/users/matjaz/events{/privacy}","received_events_url":"https://api.github.com/users/matjaz/received_events","type":"User","site_admin":false},"created_at":"2015-09-06T08:19:03Z","updated_at":"2015-09-06T08:19:03Z","body":"By the definition `this` is future value (`x'`). I wouldn't change this."}}