Dear, > > Often our search strings are only literal strings. So, we can save some time > > by using string-contains instead of invoking the regexp engine. Patch 2 does > > this. In addition, guile's string-contains uses a naive O(n^2) string search > > algorithm. We should perhaps use the O(n) Knuth-Morris-Pratt algorithm[1]. In > > fact, a comment on line 2006 of libguile/srfi-13.c in the guile source code > > mentions this. If implemented, the KMP algorithm could speed up guix search > > further. > > > > [1]: https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm It could improve. Well, I will try to do some back-to-envelop computations because I am not convinced that the mean value of 'n' (length of description, isn't) is large enough to really see an improvement for the end-user; the visible bottleneck is I/O. All the best, simon ps; To be honest, I thought this kind of algorithm was the default. :-)