[PATCH 8 of 8] fileset: add a 'status(...)' predicate to control evaluation context

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at ens-lyon.org>
# Date 1488546500 -3600
#      Fri Mar 03 14:08:20 2017 +0100
# Node ID 3e95bf7ed38189f6f56de89571fffc667280bb56
# Parent  9d6e733046b9aa7e2ded8c4207625fedcc2a8c04
# EXP-Topic filesetrev-func
# Available At https://www.mercurial-scm.org/repo/users/marmoute/mercurial/
#              hg pull https://www.mercurial-scm.org/repo/users/marmoute/mercurial/ -r 3e95bf7ed381
fileset: add a 'status(...)' predicate to control evaluation context

Same as 'revs', this predicate does not select files but switches the evaluation
context. This allow to match file according arbitrary status call. We can now
express the same query as 'hg status'.

The API (two 'revsingle' class) have been picked instead of a single 'revs'
revset for multiple reasons:

 * it is less confusing to express
 * it allow to express more query (eg: backward status, cross branch status)

diff --git a/mercurial/fileset.py b/mercurial/fileset.py
--- a/mercurial/fileset.py
+++ b/mercurial/fileset.py
@@ -463,6 +463,25 @@ def revs(mctx, x):
                 result.append(f)
     return result
 
+ at predicate('status(base, rev, pattern)')
+def status(mctx, x):
+    """``status(base, rev, revspec)``
+
+    Evaluate predicate using status change between ``base`` and
+    ``rev``. Examples:
+
+    - ``status(3, 7, added())`` - matches files added from "3" to "7"
+    """
+    repo = mctx.ctx.repo()
+    # i18n: "status" is a keyword
+    b, r, x = getargs(x, 3, 3, _("status takes three arguments"))
+    # i18n: "status" is a keyword
+    baserevspec = getstring(b, _("first argument to revs must be a revision"))
+    revspec = getstring(r, _("second argument to revs must be a revision"))
+    basectx = scmutil.revsingle(repo, baserevspec)
+    ctx = scmutil.revsingle(repo, revspec)
+    return getset(mctx.switch(ctx, _buildstatus(ctx, x, basectx=basectx)), x)
+
 @predicate('subrepo([pattern])')
 def subrepo(mctx, x):
     """Subrepositories whose paths match the given pattern.
@@ -538,6 +557,7 @@ class fullmatchctx(matchctx):
 # filesets using matchctx.switch()
 _switchcallers = [
     'revs',
+    'status',
 ]
 
 def _intree(funcs, tree):
diff --git a/tests/test-fileset.t b/tests/test-fileset.t
--- a/tests/test-fileset.t
+++ b/tests/test-fileset.t
@@ -521,3 +521,59 @@ overlapping set
 
   $ fileset "revs('1+2', modified())"
   b2
+
+test 'status(...)'
+=================
+
+Simple case
+-----------
+
+  $ fileset "status(3, 4, added())"
+  .hgsub
+  .hgsubstate
+
+use rev to restrict matched file
+-----------------------------------------
+
+  $ hg status --removed --rev 0 --rev 1
+  R a2
+  $ fileset "status(0, 1, removed())"
+  a2
+  $ fileset "* and status(0, 1, removed())"
+  $ fileset -r 4 "status(0, 1, removed())"
+  a2
+  $ fileset -r 4 "* and status(0, 1, removed())"
+  $ fileset "revs('4', * and status(0, 1, removed()))"
+  $ fileset "revs('0', * and status(0, 1, removed()))"
+  a2
+
+check wdir()
+------------
+
+  $ hg status --removed  --rev 4
+  R con.xml
+  $ fileset "status(4, 'wdir()', removed())"
+  con.xml
+
+  $ hg status --removed --rev 2
+  R a2
+  $ fileset "status('2', 'wdir()', removed())"
+  a2
+
+test backward status
+--------------------
+
+  $ hg status --removed --rev 0 --rev 4
+  R a2
+  $ hg status --added --rev 4 --rev 0
+  A a2
+  $ fileset "status(4, 0, added())"
+  a2
+
+test cross branch status
+--------------------
+
+  $ hg status --added --rev 1 --rev 2
+  A a2
+  $ fileset "status(1, 2, added())"
+  a2