| Message ID | 280943ef56a2a777ab0162b8ec4ba0166cc2095c.1594666410.git.martin.agren@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | git-diff.txt: reorder possible usages | expand |
On Mon, Jul 13, 2020 at 12:10 PM Martin Ågren <martin.agren@gmail.com> wrote: > It then goes on to say that "all of the <commit> in the above > description, except in the last two forms that use '..' notations, can > be any <tree>". The "last two" actually refers to 6 and 8. This got out > of sync in commit b7e10b2ca2 ("Documentation: usage for diff combined > commits", 2020-06-12) which added item 7 to the mix. Moving this down (as you do in this patch) is the right thing to do, but I'll note that formally, the word "that" in "forms that use ..." is part of a restrictive clause, so it means "find the last two examples that use dots". (In American English at least, the unrestrictive version would be set off with commas, and use "which" instead of "that".) > An added bonus of this commit is that we're trying to steer users away > from `git diff <commit>..<commit>` and moving it further down probably > doesn't hurt. Q: Just how hard should we try? In particular, would it be good to mark the two-dot form as deprecated in the documentation? I anticipate objections because it's not possible to omit `HEAD` without using the two-dot form. Chris
On Tue, 14 Jul 2020 at 00:04, Chris Torek <chris.torek@gmail.com> wrote: > > On Mon, Jul 13, 2020 at 12:10 PM Martin Ågren <martin.agren@gmail.com> wrote: > > It then goes on to say that "all of the <commit> in the above > > description, except in the last two forms that use '..' notations, can > > be any <tree>". The "last two" actually refers to 6 and 8. This got out > > of sync in commit b7e10b2ca2 ("Documentation: usage for diff combined > > commits", 2020-06-12) which added item 7 to the mix. > > Moving this down (as you do in this patch) is the right thing to do, > but I'll note that formally, the word "that" in "forms that use ..." is > part of a restrictive clause, so it means "find the last two examples > that use dots". (In American English at least, the unrestrictive version > would be set off with commas, and use "which" instead of "that".) Thanks, I hadn't read it like that, that makes sense. I'll learn to pay more attention to the difference between "that" and "which", which(!) I'm not sure I've fully appreciated before. So if one qualifies the ".. notations" a bit, one might actually achieve something that passes, language-lawyer-wise, even in light of the two completely different uses of "..": ..., except in the last two forms that use ".." range notations, ... or, if "the last two forms" doesn't actually add anything, ..., except in the forms that use ".." range notations, ... But I'm not sure that would help users at all, even if we might be able to say, "well, technically, it's all correct..". ;-) "The last two" seems more helpful to the reader, although it does carry the risk of getting outdated. I'm glad you agree with the move. > > An added bonus of this commit is that we're trying to steer users away > > from `git diff <commit>..<commit>` and moving it further down probably > > doesn't hurt. > > Q: Just how hard should we try? In particular, would it be good to mark > the two-dot form as deprecated in the documentation? In [1], Junio seems to be of the opinion that we can't rid ourselves of it. But yeah, I suppose we could still add something to gently get the reader to skip that particular paragraph and learn some other diff syntax or some completely different part of Git instead. The word "deprecated" seems to mean "old-school" to some and "slated for removal" to others. Maybe something along the lines of "kept for backwards compatibility to old habits". > I anticipate > objections because it's not possible to omit `HEAD` without using > the two-dot form. I always just type "HEAD". With tab-completion, I find it just as easy to go "<tab>H<tab>" as <tab><bksp>..". Martin [1] https://github.blog/2020-04-07-celebrating-15-years-of-git-an-interview-with-git-maintainer-junio-hamano/#if-you-had-a-magic-wand-what-part-of-git-would-you-fix-or-change
Chris Torek <chris.torek@gmail.com> writes: > On Mon, Jul 13, 2020 at 12:10 PM Martin Ågren <martin.agren@gmail.com> wrote: >> It then goes on to say that "all of the <commit> in the above >> description, except in the last two forms that use '..' notations, can >> be any <tree>". The "last two" actually refers to 6 and 8. This got out >> of sync in commit b7e10b2ca2 ("Documentation: usage for diff combined >> commits", 2020-06-12) which added item 7 to the mix. > > Moving this down (as you do in this patch) is the right thing to do, > but I'll note that formally, the word "that" in "forms that use ..." is > part of a restrictive clause, so it means "find the last two examples > that use dots". (In American English at least, the unrestrictive version > would be set off with commas, and use "which" instead of "that".) Yes, the proposed patch is an improvement, but I agree that "find the last two that use dots" was indeed what I meant when I wrote 0c783f66 (Documentation/git-diff: A..B and A...B cannot take tree-ishes, 2007-08-28). But upon reading it again now, I am not sure it makes sense in the first place. git diff seen^^{tree}..seen^{tree} uses <tree> (not commit) in the form that uses '..' notation, and it just works fine. What does require commit because it depends on having a history to compute merge base between two objects given from the command line is the form that uses '...' notation. git diff seen^1...seen^2 would be "what did the side branch merged at the tip of seen do since it forked?" and should look similar to "git diff seen^ seen", but it cannot use tree objects for obvious reasons git diff seen^1^{tree}...seen^2^{tree} >> An added bonus of this commit is that we're trying to steer users away >> from `git diff <commit>..<commit>` and moving it further down probably >> doesn't hurt. > > Q: Just how hard should we try? In particular, would it be good to mark > the two-dot form as deprecated in the documentation? I anticipate > objections because it's not possible to omit `HEAD` without using > the two-dot form. I am not sure why it is so important to be able to omit HEAD in the first place. I do not think using two-dot form is an offence severe enough to deserve an extra warning or deprecation notice, but using the "range" notation when you meant two endpoints is a notation that confuses uninitiated needlessly and showing it to new people is a disservice. "This notation does not make logical sense, but we keep using it as users, and we keep accepting it as tool makers, purely for convenience" has been and will be the attitude I'd take towards the "git diff A..B" syntax---it was a mistake we made when we were still young ;-) cf. https://bit.ly/3eBcyZa
diff --git a/Documentation/git-diff.txt b/Documentation/git-diff.txt index c613e71ca4..727f24d16e 100644 --- a/Documentation/git-diff.txt +++ b/Documentation/git-diff.txt @@ -63,12 +63,6 @@ files on disk. This is to view the changes between two arbitrary <commit>. -'git diff' [<options>] <commit>..<commit> [--] [<path>...]:: - - This is synonymous to the previous form. If <commit> on - one side is omitted, it will have the same effect as - using HEAD instead. - 'git diff' [<options>] <commit> <commit>... <commit> [--] [<path>...]:: This form is to view the results of a merge commit. The first @@ -78,6 +72,13 @@ files on disk. For instance, if `master` names a merge commit, `git diff master master^@` gives the same combined diff as `git show master`. +'git diff' [<options>] <commit>..<commit> [--] [<path>...]:: + + This is synonymous to the earlier form (without the "..") for + viewing the changes between two arbitrary <commit>. If <commit> on + one side is omitted, it will have the same effect as + using HEAD instead. + 'git diff' [<options>] <commit>\...<commit> [--] [<path>...]:: This form is to view the changes on the branch containing
The description of `git diff` goes through several different invocations (numbering added by me): 1. git diff [<options>] [--] [<path>...] 2. git diff [<options>] --no-index [--] <path> <path> 3. git diff [<options>] --cached [<commit>] [--] [<path>...] 4. git diff [<options>] <commit> [--] [<path>...] 5. git diff [<options>] <commit> <commit> [--] [<path>...] 6. git diff [<options>] <commit>..<commit> [--] [<path>...] 7. git diff [<options>] <commit> <commit>... <commit> [--] [<path>...] 8. git diff [<options>] <commit>...<commit> [--] [<path>...] It then goes on to say that "all of the <commit> in the above description, except in the last two forms that use '..' notations, can be any <tree>". The "last two" actually refers to 6 and 8. This got out of sync in commit b7e10b2ca2 ("Documentation: usage for diff combined commits", 2020-06-12) which added item 7 to the mix. As a further complication, after b7e10b2ca2 we also have some potential confusion around "the '..' notation". The "..[.]" in items 6 and 8 are part of the rev notation, whereas the "..." in item 7 is manpage language for "one or more". Move item 6 down, i.e., to between 7 and 8, to restore the ordering. Because 6 refers to 5 ("synonymous to the previous form") we need to tweak the language a bit. An added bonus of this commit is that we're trying to steer users away from `git diff <commit>..<commit>` and moving it further down probably doesn't hurt. Signed-off-by: Martin Ågren <martin.agren@gmail.com> --- Documentation/git-diff.txt | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)