https://github.com/grafana/loki/blob/master/pkg/iter/iterator.go#L252:6 https://github.com/grafana/loki/blob/master/pkg/iter/iterato... Looks like the Go regex

https://github.com/grafana/loki/blob/master/pkg/iter/iterator.go#L252:6 https://github.com/grafana/loki/blob/master/pkg/iter/iterato... Looks like the Go regex lib, which isn't super performant, so it could potentially be improved if it ends up being an issue.