On Mon, 8 Oct 2018, Jacob Keller wrote: > On Mon, Oct 8, 2018 at 8:22 PM Jeff King <peff@xxxxxxxx> wrote: > > > > On Tue, Oct 09, 2018 at 08:09:32AM +0900, Junio C Hamano wrote: > > > > > Julia Lawall <julia.lawall@xxxxxxx> writes: > > > > > > >> Doing the same for -S is much harder at the machinery level, as it > > > >> performs its thing without internally running "diff" twice, but just > > > >> counts the number of occurrences of 'foo'---that is sufficient for > > > >> its intended use, and more efficient. > > > > > > > > There is still the question of whether the number of occurrences of foo > > > > decreases or increases. > > > > > > Hmph, taking the changes that makes the number of hits decrease > > > would catch a subset of "changes that removes 'foo' only---I am not > > > interested in the ones that adds 'foo'". It will avoid getting > > > confused by a change that moves an existing 'foo' to another place > > > in the same file (as the number of hits does not change), but at the > > > same time, it will miss a change that genuinely removes an existing > > > 'foo' and happens to add a 'foo' at a different place in the same > > > file that is unrelated to the original 'foo'. Depending on the > > > definition of "I am only interested in removed ones", that may or > > > may not be acceptable. > > > > I think that is the best we could do for "-S", though, which is > > inherently about counting hits. > > > > For "-G", we are literally grepping the diff. It does not seem > > unreasonable to add the ability to grep only "-" or "+" lines, and the > > interface for that should be pretty straightforward (a tri-state flag to > > look in remove, added, or both lines). > > > > -Peff > > Yea. I know I've wanted something like this in the past. It could also be nice to be able to specify multiple patterns, with and and or between them. So -A&-B would be remove A somewhere and remove B somewhere. julia
