phabricator: add a small language to query Differential Revisions
Previously, `phabread` can only be used to read a single patch, or a single
stack of patches. In the future, we want to have more complex queries like
filtering with status (open, accepted, closed, etc), or maybe more complex
like filtering by reviewers etc. The command line flag approach won't scale
with that.
Besides, we might want to have other commands to update Differential
Revision status in batch, like accepting a stack using a single command.
Therefore, this patch adds a small language. It has basic set operations:
`&`, `+`, `-` and an ancestor operator to support `--stack`.
Test Plan:
Try querying this Phabricator instance:
hg phabread 1+2 # 1, 2
hg phabread D2+D1 # 2, 1
hg phabread ':118-115+:2-1' # 114, 116, 117, 118, 2
hg phabread '((:118-(D115+117)))&:117' # 114, 116
hg phabread ':2&:117' --debug # differential.query is called only once
Make sure the output is expected and prefetch works.
Differential Revision: https://phab.mercurial-scm.org/D125
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present