dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [mq]
> git = keep
> EOF
$ hg init a
$ cd a
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ echo 'patched' > base
$ hg qrefresh
qdiff:
$ hg qdiff
diff -r d20a80d4def3 base
--- a/base Thu Jan 01 00:00:00 1970 +0000
+++ b/base* (glob)
@@ -1,1 +1,1 @@
-base
+patched
qdiff dirname:
$ hg qdiff --nodates .
diff -r d20a80d4def3 base
--- a/base
+++ b/base
@@ -1,1 +1,1 @@
-base
+patched
qdiff filename:
$ hg qdiff --nodates base
diff -r d20a80d4def3 base
--- a/base
+++ b/base
@@ -1,1 +1,1 @@
-base
+patched
$ hg revert -a
$ hg qpop
popping mqbase
patch queue now empty
$ hg qdelete mqbase
$ printf '1\n2\n3\n4\nhello world\ngoodbye world\n7\n8\n9\n' > lines
$ hg ci -Amlines -d '2 0'
adding lines
$ hg qnew -mmqbase2 mqbase2
$ printf '\n\n1\n2\n3\n4\nhello world\n goodbye world\n7\n8\n9\n' > lines
$ hg qdiff --nodates -U 1
diff -r b0c220e1cf43 lines
--- a/lines
+++ b/lines
@@ -1,1 +1,3 @@
+
+
1
@@ -4,4 +6,4 @@
4
-hello world
-goodbye world
+hello world
+ goodbye world
7
$ hg qdiff --nodates -b
diff -r b0c220e1cf43 lines
--- a/lines
+++ b/lines
@@ -1,9 +1,11 @@
+
+
1
2
3
4
hello world
-goodbye world
+ goodbye world
7
8
9
$ hg qdiff --nodates -U 1 -B
diff -r b0c220e1cf43 lines
--- a/lines
+++ b/lines
@@ -4,4 +4,4 @@
4
-hello world
-goodbye world
+hello world
+ goodbye world
7
$ hg qdiff --nodates -w
diff -r b0c220e1cf43 lines
--- a/lines
+++ b/lines
@@ -1,3 +1,5 @@
+
+
1
2
3
$ hg qdiff --nodates --reverse
diff -r b0c220e1cf43 lines
--- a/lines
+++ b/lines
@@ -1,11 +1,9 @@
-
-
1
2
3
4
-hello world
- goodbye world
+hello world
+goodbye world
7
8
9
qdiff preserve existing git flag:
$ hg qrefresh --git
$ echo a >> lines
$ hg qdiff
diff --git a/lines b/lines
--- a/lines
+++ b/lines
@@ -1,9 +1,12 @@
+
+
1
2
3
4
-hello world
-goodbye world
+hello world
+ goodbye world
7
8
9
+a
$ hg qdiff --stat
lines | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
$ hg qrefresh
qdiff when file deleted (but not removed) in working dir:
$ hg qnew deleted-file
$ echo a > newfile
$ hg add newfile
$ hg qrefresh
$ rm newfile
$ hg qdiff
$ cd ..