revset: predicate to avoid lookup errors

A query like

head() and (descendants("bad") and not descendants("fix"))

(testing if repo heads are affected by a bug) will abort with a
RepoLookupError if either badrev or fixrev aren't found inside
the repository, which is not very informative.

The new predicate returns an empty set for lookup errors, so

head() and (descendants(present("bad")) and not descendants(present("fix")))

will behave as wanted even if those revisions are not found.

mercurial/help/revsets.txt

@@ -1,169 +1,173 b''
 Mercurial supports a functional language for selecting a set of
 revisions.
 
 The language supports a number of predicates which are joined by infix
 operators. Parenthesis can be used for grouping.
 
 Identifiers such as branch names must be quoted with single or double
 quotes if they contain characters outside of
 ``[._a-zA-Z0-9\x80-\xff]`` or if they match one of the predefined
 predicates. Special characters can be used in quoted identifiers by
 escaping them, e.g., ``\n`` is interpreted as a newline.
 
 There is a single prefix operator:
 
 ``not x``
   Changesets not in x. Short form is ``! x``.
 
 These are the supported infix operators:
 
 ``x::y``
   A DAG range, meaning all changesets that are descendants of x and
   ancestors of y, including x and y themselves. If the first endpoint
   is left out, this is equivalent to ``ancestors(y)``, if the second
   is left out it is equivalent to ``descendants(x)``.
 
   An alternative syntax is ``x..y``.
 
 ``x:y``
   All changesets with revision numbers between x and y, both
   inclusive. Either endpoint can be left out, they default to 0 and
   tip.
 
 ``x and y``
   The intersection of changesets in x and y. Short form is ``x & y``.
 
 ``x or y``
   The union of changesets in x and y. There are two alternative short
   forms: ``x | y`` and ``x + y``.
 
 ``x - y``
   Changesets in x but not in y.
 
 The following predicates are supported:
 
 ``adds(pattern)``
   Changesets that add a file matching pattern.
 
 ``all()``
   All changesets, the same as ``0:tip``.
 
 ``ancestor(single, single)``
   Greatest common ancestor of the two changesets.
 
 ``ancestors(set)``
   Changesets that are ancestors of a changeset in set.
 
 ``author(string)``
   Alias for ``user(string)``.
 
 ``branch(set)``
   All changesets belonging to the branches of changesets in set.
 
 ``children(set)``
   Child changesets of changesets in set.
 
 ``closed()``
   Changeset is closed.
 
 ``contains(pattern)``
   Revision contains pattern.
 
 ``date(interval)``
   Changesets within the interval, see :hg:`help dates`.
 
 ``descendants(set)``
   Changesets which are descendants of changesets in set.
 
 ``file(pattern)``
   Changesets affecting files matched by pattern.
 
 ``follow()``
   An alias for ``::.`` (ancestors of the working copy's first parent).
 
 ``grep(regex)``
   Like ``keyword(string)`` but accepts a regex.
 
 ``head()``
   Changeset is a head.
 
 ``heads(set)``
   Members of set with no children in set.
 
 ``keyword(string)``
   Search commit message, user name, and names of changed files for
   string.
 
 ``limit(set, n)``
   First n members of set.
 
 ``max(set)``
   Changeset with highest revision number in set.
 
 ``min(set)``
   Changeset with lowest revision number in set.
 
 ``merge()``
   Changeset is a merge changeset.
 
 ``modifies(pattern)``
   Changesets modifying files matched by pattern.
 
 ``outgoing([path])``
   Changesets not found in the specified destination repository, or the
   default push location.
 
 ``p1(set)``
   First parent of changesets in set.
 
 ``p2(set)``
   Second parent of changesets in set.
 
 ``parents(set)``
   The set of all parents for all changesets in set.
 
+``present(set)``
+  An empty set, if any revision in set isn't found; otherwise,
+  all revisions in set.
+
 ``removes(pattern)``
   Changesets which remove files matching pattern.
 
 ``reverse(set)``
   Reverse order of set.
 
 ``roots(set)``
   Changesets with no parent changeset in set.
 
 ``sort(set[, [-]key...])``
   Sort set by keys. The default sort order is ascending, specify a key
   as ``-key`` to sort in descending order.
 
   The keys can be:
 
   - ``rev`` for the revision number,
   - ``branch`` for the branch name,
   - ``desc`` for the commit message (description),
   - ``user`` for user name (``author`` can be used as an alias),
   - ``date`` for the commit date
 
 ``tagged()``
   Changeset is tagged.
 
 ``user(string)``
   User name is string.
 
 Command line equivalents for :hg:`log`::
 
   -f    ->  ::.
   -d x  ->  date(x)
   -k x  ->  keyword(x)
   -m    ->  merge()
   -u x  ->  user(x)
   -b x  ->  branch(x)
   -P x  ->  !::x
   -l x  ->  limit(expr, x)
 
 Some sample queries::
 
   hg log -r 'branch(default)'
   hg log -r 'branch(default) and 1.5:: and not merge()'
   hg log -r '1.3::1.5 and keyword(bug) and file("hgext/*")'
   hg log -r 'sort(date("May 2008"), user)'
   hg log -r '(keyword(bug) or keyword(issue)) and not ancestors(tagged())'

mercurial/revset.py

@@ -1,581 +1,588 b''
 # revset.py - revision set queries for mercurial
 #
 # Copyright 2010 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 import re
 import parser, util, error, discovery
 import match as _match
 from i18n import _
 
 elements = {
     "(": (20, ("group", 1, ")"), ("func", 1, ")")),
     "-": (19, ("negate", 19), ("minus", 19)),
     "::": (17, ("dagrangepre", 17), ("dagrange", 17),
            ("dagrangepost", 17)),
     "..": (17, ("dagrangepre", 17), ("dagrange", 17),
            ("dagrangepost", 17)),
     ":": (15, ("rangepre", 15), ("range", 15), ("rangepost", 15)),
     "not": (10, ("not", 10)),
     "!": (10, ("not", 10)),
     "and": (5, None, ("and", 5)),
     "&": (5, None, ("and", 5)),
     "or": (4, None, ("or", 4)),
     "|": (4, None, ("or", 4)),
     "+": (4, None, ("or", 4)),
     ",": (2, None, ("list", 2)),
     ")": (0, None, None),
     "symbol": (0, ("symbol",), None),
     "string": (0, ("string",), None),
     "end": (0, None, None),
 }
 
 keywords = set(['and', 'or', 'not'])
 
 def tokenize(program):
     pos, l = 0, len(program)
     while pos < l:
         c = program[pos]
         if c.isspace(): # skip inter-token whitespace
             pass
         elif c == ':' and program[pos:pos + 2] == '::': # look ahead carefully
             yield ('::', None, pos)
             pos += 1 # skip ahead
         elif c == '.' and program[pos:pos + 2] == '..': # look ahead carefully
             yield ('..', None, pos)
             pos += 1 # skip ahead
         elif c in "():,-|&+!": # handle simple operators
             yield (c, None, pos)
         elif c in '"\'': # handle quoted strings
             pos += 1
             s = pos
             while pos < l: # find closing quote
                 d = program[pos]
                 if d == '\\': # skip over escaped characters
                     pos += 2
                     continue
                 if d == c:
                     yield ('string', program[s:pos].decode('string-escape'), s)
                     break
                 pos += 1
             else:
                 raise error.ParseError(_("unterminated string"), s)
         elif c.isalnum() or c in '._' or ord(c) > 127: # gather up a symbol/keyword
             s = pos
             pos += 1
             while pos < l: # find end of symbol
                 d = program[pos]
                 if not (d.isalnum() or d in "._" or ord(d) > 127):
                     break
                 if d == '.' and program[pos - 1] == '.': # special case for ..
                     pos -= 1
                     break
                 pos += 1
             sym = program[s:pos]
             if sym in keywords: # operator keywords
                 yield (sym, None, s)
             else:
                 yield ('symbol', sym, s)
             pos -= 1
         else:
             raise error.ParseError(_("syntax error"), pos)
         pos += 1
     yield ('end', None, pos)
 
 # helpers
 
 def getstring(x, err):
     if x and (x[0] == 'string' or x[0] == 'symbol'):
         return x[1]
     raise error.ParseError(err)
 
 def getlist(x):
     if not x:
         return []
     if x[0] == 'list':
         return getlist(x[1]) + [x[2]]
     return [x]
 
 def getargs(x, min, max, err):
     l = getlist(x)
     if len(l) < min or len(l) > max:
         raise error.ParseError(err)
     return l
 
 def getset(repo, subset, x):
     if not x:
         raise error.ParseError(_("missing argument"))
     return methods[x[0]](repo, subset, *x[1:])
 
 # operator methods
 
 def stringset(repo, subset, x):
     x = repo[x].rev()
     if x == -1 and len(subset) == len(repo):
         return [-1]
     if x in subset:
         return [x]
     return []
 
 def symbolset(repo, subset, x):
     if x in symbols:
         raise error.ParseError(_("can't use %s here") % x)
     return stringset(repo, subset, x)
 
 def rangeset(repo, subset, x, y):
     m = getset(repo, subset, x)
     if not m:
         m = getset(repo, range(len(repo)), x)
 
     n = getset(repo, subset, y)
     if not n:
         n = getset(repo, range(len(repo)), y)
 
     if not m or not n:
         return []
     m, n = m[0], n[-1]
 
     if m < n:
         r = range(m, n + 1)
     else:
         r = range(m, n - 1, -1)
     s = set(subset)
     return [x for x in r if x in s]
 
 def andset(repo, subset, x, y):
     return getset(repo, getset(repo, subset, x), y)
 
 def orset(repo, subset, x, y):
     s = set(getset(repo, subset, x))
     s |= set(getset(repo, [r for r in subset if r not in s], y))
     return [r for r in subset if r in s]
 
 def notset(repo, subset, x):
     s = set(getset(repo, subset, x))
     return [r for r in subset if r not in s]
 
 def listset(repo, subset, a, b):
     raise error.ParseError(_("can't use a list in this context"))
 
 def func(repo, subset, a, b):
     if a[0] == 'symbol' and a[1] in symbols:
         return symbols[a[1]](repo, subset, b)
     raise error.ParseError(_("not a function: %s") % a[1])
 
 # functions
 
 def p1(repo, subset, x):
     ps = set()
     cl = repo.changelog
     for r in getset(repo, subset, x):
         ps.add(cl.parentrevs(r)[0])
     return [r for r in subset if r in ps]
 
 def p2(repo, subset, x):
     ps = set()
     cl = repo.changelog
     for r in getset(repo, subset, x):
         ps.add(cl.parentrevs(r)[1])
     return [r for r in subset if r in ps]
 
 def parents(repo, subset, x):
     ps = set()
     cl = repo.changelog
     for r in getset(repo, subset, x):
         ps.update(cl.parentrevs(r))
     return [r for r in subset if r in ps]
 
 def maxrev(repo, subset, x):
     s = getset(repo, subset, x)
     if s:
         m = max(s)
         if m in subset:
             return [m]
     return []
 
 def minrev(repo, subset, x):
     s = getset(repo, subset, x)
     if s:
         m = min(s)
         if m in subset:
             return [m]
     return []
 
 def limit(repo, subset, x):
     l = getargs(x, 2, 2, _("limit wants two arguments"))
     try:
         lim = int(getstring(l[1], _("limit wants a number")))
     except ValueError:
         raise error.ParseError(_("limit expects a number"))
     return getset(repo, subset, l[0])[:lim]
 
 def children(repo, subset, x):
     cs = set()
     cl = repo.changelog
     s = set(getset(repo, subset, x))
     for r in xrange(0, len(repo)):
         for p in cl.parentrevs(r):
             if p in s:
                 cs.add(r)
     return [r for r in subset if r in cs]
 
 def branch(repo, subset, x):
     s = getset(repo, range(len(repo)), x)
     b = set()
     for r in s:
         b.add(repo[r].branch())
     s = set(s)
     return [r for r in subset if r in s or repo[r].branch() in b]
 
 def ancestor(repo, subset, x):
     l = getargs(x, 2, 2, _("ancestor wants two arguments"))
     r = range(len(repo))
     a = getset(repo, r, l[0])
     b = getset(repo, r, l[1])
     if len(a) != 1 or len(b) != 1:
         raise error.ParseError(_("ancestor arguments must be single revisions"))
     an = [repo[a[0]].ancestor(repo[b[0]]).rev()]
 
     return [r for r in an if r in subset]
 
 def ancestors(repo, subset, x):
     args = getset(repo, range(len(repo)), x)
     if not args:
         return []
     s = set(repo.changelog.ancestors(*args)) | set(args)
     return [r for r in subset if r in s]
 
 def descendants(repo, subset, x):
     args = getset(repo, range(len(repo)), x)
     if not args:
         return []
     s = set(repo.changelog.descendants(*args)) | set(args)
     return [r for r in subset if r in s]
 
 def follow(repo, subset, x):
     getargs(x, 0, 0, _("follow takes no arguments"))
     p = repo['.'].rev()
     s = set(repo.changelog.ancestors(p)) | set([p])
     return [r for r in subset if r in s]
 
 def date(repo, subset, x):
     ds = getstring(x, _("date wants a string"))
     dm = util.matchdate(ds)
     return [r for r in subset if dm(repo[r].date()[0])]
 
 def keyword(repo, subset, x):
     kw = getstring(x, _("keyword wants a string")).lower()
     l = []
     for r in subset:
         c = repo[r]
         t = " ".join(c.files() + [c.user(), c.description()])
         if kw in t.lower():
             l.append(r)
     return l
 
 def grep(repo, subset, x):
     gr = re.compile(getstring(x, _("grep wants a string")))
     l = []
     for r in subset:
         c = repo[r]
         for e in c.files() + [c.user(), c.description()]:
             if gr.search(e):
                 l.append(r)
                 continue
     return l
 
 def author(repo, subset, x):
     n = getstring(x, _("author wants a string")).lower()
     return [r for r in subset if n in repo[r].user().lower()]
 
 def hasfile(repo, subset, x):
     pat = getstring(x, _("file wants a pattern"))
     m = _match.match(repo.root, repo.getcwd(), [pat])
     s = []
     for r in subset:
         for f in repo[r].files():
             if m(f):
                 s.append(r)
                 continue
     return s
 
 def contains(repo, subset, x):
     pat = getstring(x, _("contains wants a pattern"))
     m = _match.match(repo.root, repo.getcwd(), [pat])
     s = []
     if m.files() == [pat]:
         for r in subset:
             if pat in repo[r]:
                 s.append(r)
                 continue
     else:
         for r in subset:
             for f in repo[r].manifest():
                 if m(f):
                     s.append(r)
                     continue
     return s
 
 def checkstatus(repo, subset, pat, field):
     m = _match.match(repo.root, repo.getcwd(), [pat])
     s = []
     fast = (m.files() == [pat])
     for r in subset:
         c = repo[r]
         if fast:
             if pat not in c.files():
                 continue
         else:
             for f in c.files():
                 if m(f):
                     break
             else:
                 continue
         files = repo.status(c.p1().node(), c.node())[field]
         if fast:
             if pat in files:
                 s.append(r)
                 continue
         else:
             for f in files:
                 if m(f):
                     s.append(r)
                     continue
     return s
 
 def modifies(repo, subset, x):
     pat = getstring(x, _("modifies wants a pattern"))
     return checkstatus(repo, subset, pat, 0)
 
 def adds(repo, subset, x):
     pat = getstring(x, _("adds wants a pattern"))
     return checkstatus(repo, subset, pat, 1)
 
 def removes(repo, subset, x):
     pat = getstring(x, _("removes wants a pattern"))
     return checkstatus(repo, subset, pat, 2)
 
 def merge(repo, subset, x):
     getargs(x, 0, 0, _("merge takes no arguments"))
     cl = repo.changelog
     return [r for r in subset if cl.parentrevs(r)[1] != -1]
 
 def closed(repo, subset, x):
     getargs(x, 0, 0, _("closed takes no arguments"))
     return [r for r in subset if repo[r].extra().get('close')]
 
 def head(repo, subset, x):
     getargs(x, 0, 0, _("head takes no arguments"))
     hs = set()
     for b, ls in repo.branchmap().iteritems():
         hs.update(repo[h].rev() for h in ls)
     return [r for r in subset if r in hs]
 
 def reverse(repo, subset, x):
     l = getset(repo, subset, x)
     l.reverse()
     return l
 
+def present(repo, subset, x):
+    try:
+        return getset(repo, subset, x)
+    except error.RepoLookupError:
+        return []
+
 def sort(repo, subset, x):
     l = getargs(x, 1, 2, _("sort wants one or two arguments"))
     keys = "rev"
     if len(l) == 2:
         keys = getstring(l[1], _("sort spec must be a string"))
 
     s = l[0]
     keys = keys.split()
     l = []
     def invert(s):
         return "".join(chr(255 - ord(c)) for c in s)
     for r in getset(repo, subset, s):
         c = repo[r]
         e = []
         for k in keys:
             if k == 'rev':
                 e.append(r)
             elif k == '-rev':
                 e.append(-r)
             elif k == 'branch':
                 e.append(c.branch())
             elif k == '-branch':
                 e.append(invert(c.branch()))
             elif k == 'desc':
                 e.append(c.description())
             elif k == '-desc':
                 e.append(invert(c.description()))
             elif k in 'user author':
                 e.append(c.user())
             elif k in '-user -author':
                 e.append(invert(c.user()))
             elif k == 'date':
                 e.append(c.date()[0])
             elif k == '-date':
                 e.append(-c.date()[0])
             else:
                 raise error.ParseError(_("unknown sort key %r") % k)
         e.append(r)
         l.append(e)
     l.sort()
     return [e[-1] for e in l]
 
 def getall(repo, subset, x):
     getargs(x, 0, 0, _("all takes no arguments"))
     return subset
 
 def heads(repo, subset, x):
     s = getset(repo, subset, x)
     ps = set(parents(repo, subset, x))
     return [r for r in s if r not in ps]
 
 def roots(repo, subset, x):
     s = getset(repo, subset, x)
     cs = set(children(repo, subset, x))
     return [r for r in s if r not in cs]
 
 def outgoing(repo, subset, x):
     import hg # avoid start-up nasties
     l = getargs(x, 0, 1, _("outgoing wants a repository path"))
     dest = l and getstring(l[0], _("outgoing wants a repository path")) or ''
     dest = repo.ui.expandpath(dest or 'default-push', dest or 'default')
     dest, branches = hg.parseurl(dest)
     other = hg.repository(hg.remoteui(repo, {}), dest)
     repo.ui.pushbuffer()
     o = discovery.findoutgoing(repo, other)
     repo.ui.popbuffer()
     cl = repo.changelog
     o = set([cl.rev(r) for r in repo.changelog.nodesbetween(o, None)[0]])
     return [r for r in subset if r in o]
 
 def tagged(repo, subset, x):
     getargs(x, 0, 0, _("tagged takes no arguments"))
     cl = repo.changelog
     s = set([cl.rev(n) for t, n in repo.tagslist() if t != 'tip'])
     return [r for r in subset if r in s]
 
 symbols = {
     "adds": adds,
     "all": getall,
     "ancestor": ancestor,
     "ancestors": ancestors,
     "author": author,
     "branch": branch,
     "children": children,
     "closed": closed,
     "contains": contains,
     "date": date,
     "descendants": descendants,
     "file": hasfile,
     "follow": follow,
     "grep": grep,
     "head": head,
     "heads": heads,
     "keyword": keyword,
     "limit": limit,
     "max": maxrev,
     "min": minrev,
     "merge": merge,
     "modifies": modifies,
     "outgoing": outgoing,
     "p1": p1,
     "p2": p2,
     "parents": parents,
+    "present": present,
     "removes": removes,
     "reverse": reverse,
     "roots": roots,
     "sort": sort,
     "tagged": tagged,
     "user": author,
 }
 
 methods = {
     "range": rangeset,
     "string": stringset,
     "symbol": symbolset,
     "and": andset,
     "or": orset,
     "not": notset,
     "list": listset,
     "func": func,
 }
 
 def optimize(x, small):
     if x == None:
         return 0, x
 
     smallbonus = 1
     if small:
         smallbonus = .5
 
     op = x[0]
     if op == 'minus':
         return optimize(('and', x[1], ('not', x[2])), small)
     elif op == 'dagrange':
         return optimize(('and', ('func', ('symbol', 'descendants'), x[1]),
                          ('func', ('symbol', 'ancestors'), x[2])), small)
     elif op == 'dagrangepre':
         return optimize(('func', ('symbol', 'ancestors'), x[1]), small)
     elif op == 'dagrangepost':
         return optimize(('func', ('symbol', 'descendants'), x[1]), small)
     elif op == 'rangepre':
         return optimize(('range', ('string', '0'), x[1]), small)
     elif op == 'rangepost':
         return optimize(('range', x[1], ('string', 'tip')), small)
     elif op == 'negate':
         return optimize(('string',
                          '-' + getstring(x[1], _("can't negate that"))), small)
     elif op in 'string symbol negate':
         return smallbonus, x # single revisions are small
     elif op == 'and' or op == 'dagrange':
         wa, ta = optimize(x[1], True)
         wb, tb = optimize(x[2], True)
         w = min(wa, wb)
         if wa > wb:
             return w, (op, tb, ta)
         return w, (op, ta, tb)
     elif op == 'or':
         wa, ta = optimize(x[1], False)
         wb, tb = optimize(x[2], False)
         if wb < wa:
             wb, wa = wa, wb
         return max(wa, wb), (op, ta, tb)
     elif op == 'not':
         o = optimize(x[1], not small)
         return o[0], (op, o[1])
     elif op == 'group':
         return optimize(x[1], small)
     elif op in 'range list':
         wa, ta = optimize(x[1], small)
         wb, tb = optimize(x[2], small)
         return wa + wb, (op, ta, tb)
     elif op == 'func':
         f = getstring(x[1], _("not a symbol"))
         wa, ta = optimize(x[2], small)
         if f in "grep date user author keyword branch file":
             w = 10 # slow
         elif f in "modifies adds removes outgoing":
             w = 30 # slower
         elif f == "contains":
             w = 100 # very slow
         elif f == "ancestor":
             w = 1 * smallbonus
         elif f == "reverse limit":
             w = 0
         elif f in "sort":
             w = 10 # assume most sorts look at changelog
         else:
             w = 1
         return w + wa, (op, x[1], ta)
     return 1, x
 
 parse = parser.parser(tokenize, elements).parse
 
 def match(spec):
     if not spec:
         raise error.ParseError(_("empty query"))
     tree = parse(spec)
     weight, tree = optimize(tree, True)
     def mfunc(repo, subset):
         return getset(repo, subset, tree)
     return mfunc