{"action":"opened","issue":{"url":"https://api.github.com/repos/rust-lang/regex/issues/24","labels_url":"https://api.github.com/repos/rust-lang/regex/issues/24/labels{/name}","comments_url":"https://api.github.com/repos/rust-lang/regex/issues/24/comments","events_url":"https://api.github.com/repos/rust-lang/regex/issues/24/events","html_url":"https://github.com/rust-lang/regex/issues/24","id":55066946,"number":24,"title":"[CLOSED] Regexes appear to be significantly slower than re2 in some cases","user":{"login":"steveklabnik","id":27786,"avatar_url":"https://avatars.githubusercontent.com/u/27786?v=3","gravatar_id":"","url":"https://api.github.com/users/steveklabnik","html_url":"https://github.com/steveklabnik","followers_url":"https://api.github.com/users/steveklabnik/followers","following_url":"https://api.github.com/users/steveklabnik/following{/other_user}","gists_url":"https://api.github.com/users/steveklabnik/gists{/gist_id}","starred_url":"https://api.github.com/users/steveklabnik/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/steveklabnik/subscriptions","organizations_url":"https://api.github.com/users/steveklabnik/orgs","repos_url":"https://api.github.com/users/steveklabnik/repos","events_url":"https://api.github.com/users/steveklabnik/events{/privacy}","received_events_url":"https://api.github.com/users/steveklabnik/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-01-21T19:41:31Z","updated_at":"2015-01-21T19:41:31Z","closed_at":null,"body":"<a href=\"https://github.com/brson\"><img src=\"https://avatars.githubusercontent.com/u/147214?v=3\" align=\"left\" width=\"96\" height=\"96\" hspace=\"10\"></img></a> **Issue by [brson](https://github.com/brson)**\n_Thursday Sep 04, 2014 at 18:15 GMT_\n\n_For earlier discussion, see https://github.com/rust-lang/rust/issues/16989_\n\n_This issue was labelled with: A-an-interesting-project, A-libs, I-slow in the Rust repository_\n\n----\n\nMy understanding is that we believe them to be competitive, but two benchmarks I've seen were not really in the ballpark. The easiest one to test is the shootout's [regexdna](https://gist.github.com/brson/fd4d620d6aac03b5db21), which you can see from the [upstream shootout](http://benchmarksgame.alioth.debian.org/u64q/rust.php) is drastically slower than the re2-based C++ implementation.\r\n\r\ncc @BurntSushi\n"}}