Engineer at Sourcegraph here. Adding boolean operators is a priority on our roadmap, and expected to go live between May and July this year. On separate inputs: definitely something we've also identified and are actively working on. One recent experimental addition is "Interactive mode" that lets you enter patterns separately for repos, files, and patterns, and so on. There's a dropdown next to the query bar to try it out--there are some kinks, and we're currently working on making this a polished feature. Thanks for the feedback, and stay tuned!