On Tue, Dec 12, 2023 at 11:30:03PM +0100, René Scharfe wrote: > Am 12.12.23 um 21:09 schrieb Jeff King: > > On Tue, Dec 12, 2023 at 05:17:47PM +0000, AtariDreams via GitGitGadget wrote: > > > >> diff --git a/diff.c b/diff.c > >> index 2c602df10a3..91842b54753 100644 > >> --- a/diff.c > >> +++ b/diff.c > >> @@ -1191,7 +1191,7 @@ static void mark_color_as_moved(struct diff_options *o, > >> &pmb_nr); > >> > >> if (contiguous && pmb_nr && moved_symbol == l->s) > >> - flipped_block = (flipped_block + 1) % 2; > >> + flipped_block ^= 1; > >> else > >> flipped_block = 0; > > > > This one I do not see any problem with changing, though I think it is a > > matter of opinion on which is more readable (I actually tend to think of > > "x = 0 - x" as idiomatic for flipping). > > Did you mean "x = 1 - x"? Oops, yes, of course. I'm not sure how I managed to fumble that. > I don't particular like this; it repeats x and seems error-prone. ;-) Yes. :) Without digging into the code, I had just assumed that flipped_block was used as an array index. But it really is a boolean, so I actually think "flipped_block = !flipped_block" would probably be the most clear (but IMHO not really worth the churn). > Can we salvage something from this bikeshedding exercise? I wonder if > it's time to use the C99 type _Bool in our code. It would allow > documenting that only two possible values exist in cases like the one > above. That would be even more useful for function returns, I assume. Hmm, possibly. I guess that might have helped my confusion, and I do think returning bool for function returns would help make their meaning more clear (it would help distinguish them from the usual "0 for success" return values). I don't even know that we'd need much of a weather-balloon patch. I think it would be valid to do: #ifndef bool #define bool int to handle pre-C99 compilers (if there even are any these days). Of course we probably need some conditional magic to try to "#include <stdbool.h>" for the actual C99. I guess we could assume C99 by default and then add NO_STDBOOL as an escape hatch if anybody complains. -Peff
