Bulk move and some of its close relatives

[Yann Dirson <ydirson@free.fr>]

On Mon, Oct 25, 2010 at 10:12:27PM +0200, Yann Dirson wrote:
> It is only later that I realized that the larger picture was about
> bulk moves, and directory renames were only a subset of those.

I had a couple of thoughts about this dir-rename -> bulk-moves shift
today while riding to/from work.  So here are some of the fresh air I
got...

Is a bulk-move finally so special ?  There is a close relative to it
which may be of interest too: bulk deletion.  If we implement
detection of bulk deletion, we can build on it to get:

* detection of a new type of conflict: addition in a branch of a new
  file in a dir which is deleted in the other branch (quite similar to
  the one we were talking about, of a new file in a dir that got moved in
  other branch)
* split a good part of the current bulk-move patch in a standalone
  patch, which is something I wondered how to do
* probably a much better base for directory-split detection


Then, since a bulk-move is made of a bulk deletion, and addition
somewhere else of those deleted files, it became tempting to
contemplate the concept of "bulk addition".  At first sight it seems
awkward, I confess, especially "bulk addition into a preexisting dir",
which is a bit hard to define with precision.  OTOH, "bulk addition of
a brand new dir" could bring goodies as well:

* new conflict type: creation in both branches of a new directory with
  same name

That confict type made me think of another one.  Some of you may have
noticed in the v7 commit message a suggestion for future developments
labelled "support other types of bluk-grouping, like prefixes, and
maybe config-specified patterns".  Now if we get the capability of
specifying how we define a "group of files" with something other than
the directory hierarchy (let's say eg. that in t/ every "t[0-9]{4}-"
is a prefix), the "bulk-add/bulk-add" conflict generated by 2 tests
with same numeric ID would be detected as a conflict.

Another grouping example would be by file suffix - source-code reorgs
eg. bulk-moving header files into their own dir are not rare either.


Does that sound sane ?
-- 
Yann