revset: speedup matching() by first matching fields that take less time to match This patch sorts the fields that are passed to the matching function so that it always starts by matching those fields that take less time to match. Not all fields take the same amount of time to match. I've done several measurements running the following command: hg --time log -r "matching(1, field)" on the mercurial repository, and where 'field' was each one of the fields accepted by match. In order to avoid the print overhead (which could be different for different fields, given the different number of matches) I used a modified version of the matching() function which always returns no matches. These tests showed that different fields take wildly different amounts of time to match. Particulary the substate field takes up to 25 seconds to match on my machine, compared to the 0.3 seconds that takes to match the phase field or the 2 seconds (approx) that takes to match most fields. With this patch, matching both the phase and the substate of a revision takes the same amount of time as matching the phase. The field match order introduced by this patch is as follows: phase, parents, user, date, branch, summary, files, description, substate An extra nice thing about this patch is that it makes the match time stable.