{"action":"created","issue":{"url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/14","labels_url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/14/labels{/name}","comments_url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/14/comments","events_url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/14/events","html_url":"https://github.com/SWI-Prolog/roadmap/issues/14","id":108473468,"number":14,"title":"Attributed variables: Interface convergence","user":{"login":"triska","id":7482140,"avatar_url":"https://avatars.githubusercontent.com/u/7482140?v=3","gravatar_id":"","url":"https://api.github.com/users/triska","html_url":"https://github.com/triska","followers_url":"https://api.github.com/users/triska/followers","following_url":"https://api.github.com/users/triska/following{/other_user}","gists_url":"https://api.github.com/users/triska/gists{/gist_id}","starred_url":"https://api.github.com/users/triska/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/triska/subscriptions","organizations_url":"https://api.github.com/users/triska/orgs","repos_url":"https://api.github.com/users/triska/repos","events_url":"https://api.github.com/users/triska/events{/privacy}","received_events_url":"https://api.github.com/users/triska/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/SWI-Prolog/roadmap/labels/Core","name":"Core","color":"5319e7"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":43,"created_at":"2015-09-26T14:54:54Z","updated_at":"2015-12-26T01:36:02Z","closed_at":null,"body":"The SWI interface for attributed variables is currently not general enough to express what is needed.\r\n\r\nExample, taken from `library(clpb)`: `X = Y` should be equivalent to `sat(X =:= Y)`.\r\n\r\nThere thus are cases where we need to reason about variables *before* the unification takes place or, equivalently, any pre-existing triggering unifications are *undone* before the hook is called.\r\n\r\nI recommend convergence with the interface used by SICStus Prolog, also to increase portability across different Prolog systems, or the design of an interface that is at least as general. Please contact me if you have any questions about this issue and want to work on it."},"comment":{"url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/comments/167269732","html_url":"https://github.com/SWI-Prolog/roadmap/issues/14#issuecomment-167269732","issue_url":"https://api.github.com/repos/SWI-Prolog/roadmap/issues/14","id":167269732,"user":{"login":"logicmoo","id":466945,"avatar_url":"https://avatars.githubusercontent.com/u/466945?v=3","gravatar_id":"","url":"https://api.github.com/users/logicmoo","html_url":"https://github.com/logicmoo","followers_url":"https://api.github.com/users/logicmoo/followers","following_url":"https://api.github.com/users/logicmoo/following{/other_user}","gists_url":"https://api.github.com/users/logicmoo/gists{/gist_id}","starred_url":"https://api.github.com/users/logicmoo/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/logicmoo/subscriptions","organizations_url":"https://api.github.com/users/logicmoo/orgs","repos_url":"https://api.github.com/users/logicmoo/repos","events_url":"https://api.github.com/users/logicmoo/events{/privacy}","received_events_url":"https://api.github.com/users/logicmoo/received_events","type":"User","site_admin":false},"created_at":"2015-12-26T01:36:02Z","updated_at":"2015-12-26T01:36:02Z","body":"Hopefully will get to this over the next 48 hours .. I had been doing xmas travels"}}