update use cases

1 files changed, 31 insertions, 8 deletions

diff --git a/README.md b/README.md
index b027411..7ba8a8d 100644
--- a/README.md
+++ b/README.md
@@ -66,6 +66,12 @@ Sometimes it is useful to understand the nature of parts of this DAG,
 as its nature will impact the success or failure of operations
 including merge, rebase, cherry-pick etc.
 
+Several use cases are listed in detail below.  They are also
+[mentioned in the presentation I gave in September
+2018](https://aspiers.github.io/denver-git-automagic-sept-2018/#/git-deps-motivation)
+(see also [the video](https://youtu.be/f6anrSKCIgI?t=216)).
+
+
 ### Use case 1: porting between branches
 
 For example when porting a commit "A" between git branches via `git
@@ -90,7 +96,7 @@ opportunities for selective pruning or other editing of commits during
 the backport process which may be able to reduce the number of commits
 which are required.
 
-### Use case 2: splitting a patch series
+### Use case 2: splitting a patch series into independent topics
 
 Large patch series or pull requests can be quite daunting for project
 maintainers, since they are hard to conquer in one sitting.  For this
@@ -108,6 +114,14 @@ will allow you to untangle things and expose subgraphs which can be
 cleanly split off into separate patch series or pull requests for
 submission.
 
+In fact this technique is sufficiently useful but tedious to do
+manually that I wrote a whole separate tool
+[`git-explode`](https://github.com/aspiers/git-explode) to automate
+the process.  It uses `git-deps` as a library module behind the scenes
+for the dependency inference.  See [the
+`README`](https://github.com/aspiers/git-explode/blob/master/README.rst)
+for more details.
+
 ### Use case 3: aiding collaborative communication
 
 Another use case might be to better understand levels of specialism /
@@ -178,18 +192,27 @@ In the future, this script could be extended to optionally run the
 interactive `rebase`, so that the whole amendment process is taken
 care of by `git-fixup`.
 
+### Use case 5: rewriting commit history
+
+It is often useful to reorder or rewrite commit history within private
+branches, as part of a history polishing process which ensures that
+eventually published history is of a high quality (see ["On Sausage
+Making"](https://sethrobertson.github.io/GitBestPractices/#sausage)).
+
+However reordering or removing commits can cause conflicts.  Whilst
+`git-deps` can programmatically predict whether operations such as
+merge / rebase / cherry-pick would succeed, actually it's probably
+cheaper and more reliable simply to perform the operation and then
+roll back.  However `git-deps` could be used to detect ways to avoid
+these conflicts, for example reordering or removing a commit's
+dependencies along with the commit itself.  In the future tools could
+be built on top of `git-deps` to automate these processes.
+
 ### Other uses
 
 I'm sure there are other use cases I haven't yet thought of.  If you
 have any good ideas, [please submit them](CONTRIBUTING.md)!
 
-### Non-use cases
-
-At first I thought that `git-deps` might provide a useful way to
-programmatically predict whether operations such as merge / rebase /
-cherry-pick would succeed, but actually it's probably cheaper and more
-reliable simply to perform the operation and then roll back.
-
 
 Installation
 ------------