Hi Kristoffer, On Mon, 3 Apr 2023, Kristoffer Haugsbakk wrote: > On Tue, Mar 28, 2023, at 13:37, Johannes Schindelin wrote: > > So even making the exact error message depend on the number of > > arguments could result in misleading error message. > > Yeah, I see. It seems that the variadic nature of the command makes it > difficult to guess what the user might have meant in all cases. > > > Do you have any splendid idea how to phrase the error message (or > > adapt it to the concrete invocation)? > > No. I was going to look more closely at that if-else chain, but given > the fact that I don’t know C and all the cases that would need to be > covered (“what if the third argument happens to match both a ref and a > file?”) I wouldn’t get anywhere. Knowledge of C is not required to come up with an error message ;-) The forms in which `git range-diff` can be called are: git range-diff A...B [[--] <path>...] git range-diff A..B C..D [[--] <path>...] git range-diff A B C [[--] <path>...] In general, I find it hard to guess which form was meant when a typo causes an error message. For example, `git range-diff A..B C` might have been intended to be the three-rev form `A B C`, but it could also have been intended to pass two commit ranges `A..B HEAD..C`. As such, I wonder whether we can just cleverly _avoid_ saying _which_ form we suspect the user to have intended. In other words, instead of need two commit ranges we could say: `range-diff` needs three revs, two ranges or a symmetric range Since this does not require any C expertise, it would probably be a good idea to let C experts work on other patches, patches that do require their expertise: The patch to improve the error message does not require any knowledge of the C language at all. Ciao, Johannes
