Re: Fwd: Possibly nicer pathspec syntax?

[Linus Torvalds <torvalds@linux-foundation.org>]

On Tue, Feb 7, 2017 at 6:40 PM, Mike Hommey <mh@glandium.org> wrote:
>
> As such, the default positive match should be ':/' (which is shorter and
> less cumbersome than ':(top)', btw)

So that's what my patch does.

However, it's actually very counter-intuitive in a subdirectory.

Git doesn't do much of that, but let me give you an example from the
kernel. Again, this is not an example of anything I would do (because
I'm always at the top), but:

  [torvalds@i7 linux]$ cd drivers/
  [torvalds@i7 drivers]$ ll

  .. whee, *lots* of diorectories ..
  .. lets see what happened in net/ ..

  [torvalds@i7 drivers]$ git diff -M --dirstat=1,cumulative
v4.10-rc6..v4.10-rc7 -- net/
     7.4% drivers/net/ethernet/adaptec/
    47.9% drivers/net/ethernet/cadence/
     7.1% drivers/net/ethernet/emulex/benet/
     1.1% drivers/net/ethernet/freescale/
     3.6% drivers/net/ethernet/mellanox/mlx4/
    23.5% drivers/net/ethernet/mellanox/mlx5/core/
    27.2% drivers/net/ethernet/mellanox/
    92.5% drivers/net/ethernet/
     5.3% drivers/net/wireless/intel/iwlwifi/mvm/
     5.9% drivers/net/wireless/intel/iwlwifi/
   100.0% drivers/net/

  .. let's see what happened *outside* of net/ ..

[torvalds@i7 drivers]$ git diff -M --dirstat=1,cumulative
v4.10-rc6..v4.10-rc7 -- :^net/
   2.4% arch/arm64/crypto/
   2.1% arch/powerpc/include/asm/
   1.5% arch/powerpc/kernel/
   3.9% arch/powerpc/
   3.5% arch/sparc/kernel/
   4.1% arch/sparc/
   8.3% arch/x86/events/intel/
   1.7% arch/x86/kernel/cpu/mcheck/
   1.6% arch/x86/kernel/cpu/microcode/
   3.3% arch/x86/kernel/cpu/
   3.8% arch/x86/kernel/
   1.0% arch/x86/platform/efi/
  13.3% arch/x86/
  24.0% arch/
   1.1% drivers/base/
   2.9% drivers/dma/
  12.3% drivers/gpu/drm/i915/
   1.0% drivers/gpu/drm/nouveau/
  16.2% drivers/gpu/drm/
   3.9% drivers/hid/
   1.6% drivers/iio/
   2.3% drivers/regulator/
   ...

Notice? When you say "show only the net subdirectory" it does the
obvious thing relative to the current working directory, but if you
say "show everything _but_ the net subdirectory" it suddenly starts
showing other things.

Now, it would be easy enough to say "if you don't give a positive
path, we'll just use the empty path that matches the negative paths".
So if you ask for a negative relative "net" directory, we'll use the
relative empty path. And if you ask for a negative absolute path,
we'll use the empty absolute path.

It's a couple of lines more, and I think it might avoid some confusion.

And I suspect almost nobody has ever done any of this before,. because
the syntax was/is so cumbersome.

                Linus