--- a/mercurial/revset.py	Wed Jan 25 22:39:17 2017 +0900
+++ b/mercurial/revset.py	Sun Oct 16 17:28:51 2016 +0900
@@ -26,9 +26,15 @@
     pycompat,
     registrar,
     repoview,
+    smartset,
     util,
 )
 
+baseset = smartset.baseset
+generatorset = smartset.generatorset
+spanset = smartset.spanset
+fullreposet = smartset.fullreposet
+
 def _revancestors(repo, revs, followfirst):
     """Like revlog.ancestors(), but supports followfirst."""
     if followfirst:
@@ -2940,967 +2946,6 @@
             funcs.add(tree[1][1])
         return funcs
 
-def _formatsetrepr(r):
-    """Format an optional printable representation of a set
-
-    ========  =================================
-    type(r)   example
-    ========  =================================
-    tuple     ('<not %r>', other)
-    str       '<branch closed>'
-    callable  lambda: '<branch %r>' % sorted(b)
-    object    other
-    ========  =================================
-    """
-    if r is None:
-        return ''
-    elif isinstance(r, tuple):
-        return r[0] % r[1:]
-    elif isinstance(r, str):
-        return r
-    elif callable(r):
-        return r()
-    else:
-        return repr(r)
-
-class abstractsmartset(object):
-
-    def __nonzero__(self):
-        """True if the smartset is not empty"""
-        raise NotImplementedError()
-
-    def __contains__(self, rev):
-        """provide fast membership testing"""
-        raise NotImplementedError()
-
-    def __iter__(self):
-        """iterate the set in the order it is supposed to be iterated"""
-        raise NotImplementedError()
-
-    # Attributes containing a function to perform a fast iteration in a given
-    # direction. A smartset can have none, one, or both defined.
-    #
-    # Default value is None instead of a function returning None to avoid
-    # initializing an iterator just for testing if a fast method exists.
-    fastasc = None
-    fastdesc = None
-
-    def isascending(self):
-        """True if the set will iterate in ascending order"""
-        raise NotImplementedError()
-
-    def isdescending(self):
-        """True if the set will iterate in descending order"""
-        raise NotImplementedError()
-
-    def istopo(self):
-        """True if the set will iterate in topographical order"""
-        raise NotImplementedError()
-
-    def min(self):
-        """return the minimum element in the set"""
-        if self.fastasc is None:
-            v = min(self)
-        else:
-            for v in self.fastasc():
-                break
-            else:
-                raise ValueError('arg is an empty sequence')
-        self.min = lambda: v
-        return v
-
-    def max(self):
-        """return the maximum element in the set"""
-        if self.fastdesc is None:
-            return max(self)
-        else:
-            for v in self.fastdesc():
-                break
-            else:
-                raise ValueError('arg is an empty sequence')
-        self.max = lambda: v
-        return v
-
-    def first(self):
-        """return the first element in the set (user iteration perspective)
-
-        Return None if the set is empty"""
-        raise NotImplementedError()
-
-    def last(self):
-        """return the last element in the set (user iteration perspective)
-
-        Return None if the set is empty"""
-        raise NotImplementedError()
-
-    def __len__(self):
-        """return the length of the smartsets
-
-        This can be expensive on smartset that could be lazy otherwise."""
-        raise NotImplementedError()
-
-    def reverse(self):
-        """reverse the expected iteration order"""
-        raise NotImplementedError()
-
-    def sort(self, reverse=True):
-        """get the set to iterate in an ascending or descending order"""
-        raise NotImplementedError()
-
-    def __and__(self, other):
-        """Returns a new object with the intersection of the two collections.
-
-        This is part of the mandatory API for smartset."""
-        if isinstance(other, fullreposet):
-            return self
-        return self.filter(other.__contains__, condrepr=other, cache=False)
-
-    def __add__(self, other):
-        """Returns a new object with the union of the two collections.
-
-        This is part of the mandatory API for smartset."""
-        return addset(self, other)
-
-    def __sub__(self, other):
-        """Returns a new object with the substraction of the two collections.
-
-        This is part of the mandatory API for smartset."""
-        c = other.__contains__
-        return self.filter(lambda r: not c(r), condrepr=('<not %r>', other),
-                           cache=False)
-
-    def filter(self, condition, condrepr=None, cache=True):
-        """Returns this smartset filtered by condition as a new smartset.
-
-        `condition` is a callable which takes a revision number and returns a
-        boolean. Optional `condrepr` provides a printable representation of
-        the given `condition`.
-
-        This is part of the mandatory API for smartset."""
-        # builtin cannot be cached. but do not needs to
-        if cache and util.safehasattr(condition, 'func_code'):
-            condition = util.cachefunc(condition)
-        return filteredset(self, condition, condrepr)
-
-class baseset(abstractsmartset):
-    """Basic data structure that represents a revset and contains the basic
-    operation that it should be able to perform.
-
-    Every method in this class should be implemented by any smartset class.
-    """
-    def __init__(self, data=(), datarepr=None, istopo=False):
-        """
-        datarepr: a tuple of (format, obj, ...), a function or an object that
-                  provides a printable representation of the given data.
-        """
-        self._ascending = None
-        self._istopo = istopo
-        if not isinstance(data, list):
-            if isinstance(data, set):
-                self._set = data
-                # set has no order we pick one for stability purpose
-                self._ascending = True
-            data = list(data)
-        self._list = data
-        self._datarepr = datarepr
-
-    @util.propertycache
-    def _set(self):
-        return set(self._list)
-
-    @util.propertycache
-    def _asclist(self):
-        asclist = self._list[:]
-        asclist.sort()
-        return asclist
-
-    def __iter__(self):
-        if self._ascending is None:
-            return iter(self._list)
-        elif self._ascending:
-            return iter(self._asclist)
-        else:
-            return reversed(self._asclist)
-
-    def fastasc(self):
-        return iter(self._asclist)
-
-    def fastdesc(self):
-        return reversed(self._asclist)
-
-    @util.propertycache
-    def __contains__(self):
-        return self._set.__contains__
-
-    def __nonzero__(self):
-        return bool(self._list)
-
-    def sort(self, reverse=False):
-        self._ascending = not bool(reverse)
-        self._istopo = False
-
-    def reverse(self):
-        if self._ascending is None:
-            self._list.reverse()
-        else:
-            self._ascending = not self._ascending
-        self._istopo = False
-
-    def __len__(self):
-        return len(self._list)
-
-    def isascending(self):
-        """Returns True if the collection is ascending order, False if not.
-
-        This is part of the mandatory API for smartset."""
-        if len(self) <= 1:
-            return True
-        return self._ascending is not None and self._ascending
-
-    def isdescending(self):
-        """Returns True if the collection is descending order, False if not.
-
-        This is part of the mandatory API for smartset."""
-        if len(self) <= 1:
-            return True
-        return self._ascending is not None and not self._ascending
-
-    def istopo(self):
-        """Is the collection is in topographical order or not.
-
-        This is part of the mandatory API for smartset."""
-        if len(self) <= 1:
-            return True
-        return self._istopo
-
-    def first(self):
-        if self:
-            if self._ascending is None:
-                return self._list[0]
-            elif self._ascending:
-                return self._asclist[0]
-            else:
-                return self._asclist[-1]
-        return None
-
-    def last(self):
-        if self:
-            if self._ascending is None:
-                return self._list[-1]
-            elif self._ascending:
-                return self._asclist[-1]
-            else:
-                return self._asclist[0]
-        return None
-
-    def __repr__(self):
-        d = {None: '', False: '-', True: '+'}[self._ascending]
-        s = _formatsetrepr(self._datarepr)
-        if not s:
-            l = self._list
-            # if _list has been built from a set, it might have a different
-            # order from one python implementation to another.
-            # We fallback to the sorted version for a stable output.
-            if self._ascending is not None:
-                l = self._asclist
-            s = repr(l)
-        return '<%s%s %s>' % (type(self).__name__, d, s)
-
-class filteredset(abstractsmartset):
-    """Duck type for baseset class which iterates lazily over the revisions in
-    the subset and contains a function which tests for membership in the
-    revset
-    """
-    def __init__(self, subset, condition=lambda x: True, condrepr=None):
-        """
-        condition: a function that decide whether a revision in the subset
-                   belongs to the revset or not.
-        condrepr: a tuple of (format, obj, ...), a function or an object that
-                  provides a printable representation of the given condition.
-        """
-        self._subset = subset
-        self._condition = condition
-        self._condrepr = condrepr
-
-    def __contains__(self, x):
-        return x in self._subset and self._condition(x)
-
-    def __iter__(self):
-        return self._iterfilter(self._subset)
-
-    def _iterfilter(self, it):
-        cond = self._condition
-        for x in it:
-            if cond(x):
-                yield x
-
-    @property
-    def fastasc(self):
-        it = self._subset.fastasc
-        if it is None:
-            return None
-        return lambda: self._iterfilter(it())
-
-    @property
-    def fastdesc(self):
-        it = self._subset.fastdesc
-        if it is None:
-            return None
-        return lambda: self._iterfilter(it())
-
-    def __nonzero__(self):
-        fast = None
-        candidates = [self.fastasc if self.isascending() else None,
-                      self.fastdesc if self.isdescending() else None,
-                      self.fastasc,
-                      self.fastdesc]
-        for candidate in candidates:
-            if candidate is not None:
-                fast = candidate
-                break
-
-        if fast is not None:
-            it = fast()
-        else:
-            it = self
-
-        for r in it:
-            return True
-        return False
-
-    def __len__(self):
-        # Basic implementation to be changed in future patches.
-        # until this gets improved, we use generator expression
-        # here, since list comprehensions are free to call __len__ again
-        # causing infinite recursion
-        l = baseset(r for r in self)
-        return len(l)
-
-    def sort(self, reverse=False):
-        self._subset.sort(reverse=reverse)
-
-    def reverse(self):
-        self._subset.reverse()
-
-    def isascending(self):
-        return self._subset.isascending()
-
-    def isdescending(self):
-        return self._subset.isdescending()
-
-    def istopo(self):
-        return self._subset.istopo()
-
-    def first(self):
-        for x in self:
-            return x
-        return None
-
-    def last(self):
-        it = None
-        if self.isascending():
-            it = self.fastdesc
-        elif self.isdescending():
-            it = self.fastasc
-        if it is not None:
-            for x in it():
-                return x
-            return None #empty case
-        else:
-            x = None
-            for x in self:
-                pass
-            return x
-
-    def __repr__(self):
-        xs = [repr(self._subset)]
-        s = _formatsetrepr(self._condrepr)
-        if s:
-            xs.append(s)
-        return '<%s %s>' % (type(self).__name__, ', '.join(xs))
-
-def _iterordered(ascending, iter1, iter2):
-    """produce an ordered iteration from two iterators with the same order
-
-    The ascending is used to indicated the iteration direction.
-    """
-    choice = max
-    if ascending:
-        choice = min
-
-    val1 = None
-    val2 = None
-    try:
-        # Consume both iterators in an ordered way until one is empty
-        while True:
-            if val1 is None:
-                val1 = next(iter1)
-            if val2 is None:
-                val2 = next(iter2)
-            n = choice(val1, val2)
-            yield n
-            if val1 == n:
-                val1 = None
-            if val2 == n:
-                val2 = None
-    except StopIteration:
-        # Flush any remaining values and consume the other one
-        it = iter2
-        if val1 is not None:
-            yield val1
-            it = iter1
-        elif val2 is not None:
-            # might have been equality and both are empty
-            yield val2
-        for val in it:
-            yield val
-
-class addset(abstractsmartset):
-    """Represent the addition of two sets
-
-    Wrapper structure for lazily adding two structures without losing much
-    performance on the __contains__ method
-
-    If the ascending attribute is set, that means the two structures are
-    ordered in either an ascending or descending way. Therefore, we can add
-    them maintaining the order by iterating over both at the same time
-
-    >>> xs = baseset([0, 3, 2])
-    >>> ys = baseset([5, 2, 4])
-
-    >>> rs = addset(xs, ys)
-    >>> bool(rs), 0 in rs, 1 in rs, 5 in rs, rs.first(), rs.last()
-    (True, True, False, True, 0, 4)
-    >>> rs = addset(xs, baseset([]))
-    >>> bool(rs), 0 in rs, 1 in rs, rs.first(), rs.last()
-    (True, True, False, 0, 2)
-    >>> rs = addset(baseset([]), baseset([]))
-    >>> bool(rs), 0 in rs, rs.first(), rs.last()
-    (False, False, None, None)
-
-    iterate unsorted:
-    >>> rs = addset(xs, ys)
-    >>> # (use generator because pypy could call len())
-    >>> list(x for x in rs)  # without _genlist
-    [0, 3, 2, 5, 4]
-    >>> assert not rs._genlist
-    >>> len(rs)
-    5
-    >>> [x for x in rs]  # with _genlist
-    [0, 3, 2, 5, 4]
-    >>> assert rs._genlist
-
-    iterate ascending:
-    >>> rs = addset(xs, ys, ascending=True)
-    >>> # (use generator because pypy could call len())
-    >>> list(x for x in rs), list(x for x in rs.fastasc())  # without _asclist
-    ([0, 2, 3, 4, 5], [0, 2, 3, 4, 5])
-    >>> assert not rs._asclist
-    >>> len(rs)
-    5
-    >>> [x for x in rs], [x for x in rs.fastasc()]
-    ([0, 2, 3, 4, 5], [0, 2, 3, 4, 5])
-    >>> assert rs._asclist
-
-    iterate descending:
-    >>> rs = addset(xs, ys, ascending=False)
-    >>> # (use generator because pypy could call len())
-    >>> list(x for x in rs), list(x for x in rs.fastdesc())  # without _asclist
-    ([5, 4, 3, 2, 0], [5, 4, 3, 2, 0])
-    >>> assert not rs._asclist
-    >>> len(rs)
-    5
-    >>> [x for x in rs], [x for x in rs.fastdesc()]
-    ([5, 4, 3, 2, 0], [5, 4, 3, 2, 0])
-    >>> assert rs._asclist
-
-    iterate ascending without fastasc:
-    >>> rs = addset(xs, generatorset(ys), ascending=True)
-    >>> assert rs.fastasc is None
-    >>> [x for x in rs]
-    [0, 2, 3, 4, 5]
-
-    iterate descending without fastdesc:
-    >>> rs = addset(generatorset(xs), ys, ascending=False)
-    >>> assert rs.fastdesc is None
-    >>> [x for x in rs]
-    [5, 4, 3, 2, 0]
-    """
-    def __init__(self, revs1, revs2, ascending=None):
-        self._r1 = revs1
-        self._r2 = revs2
-        self._iter = None
-        self._ascending = ascending
-        self._genlist = None
-        self._asclist = None
-
-    def __len__(self):
-        return len(self._list)
-
-    def __nonzero__(self):
-        return bool(self._r1) or bool(self._r2)
-
-    @util.propertycache
-    def _list(self):
-        if not self._genlist:
-            self._genlist = baseset(iter(self))
-        return self._genlist
-
-    def __iter__(self):
-        """Iterate over both collections without repeating elements
-
-        If the ascending attribute is not set, iterate over the first one and
-        then over the second one checking for membership on the first one so we
-        dont yield any duplicates.
-
-        If the ascending attribute is set, iterate over both collections at the
-        same time, yielding only one value at a time in the given order.
-        """
-        if self._ascending is None:
-            if self._genlist:
-                return iter(self._genlist)
-            def arbitraryordergen():
-                for r in self._r1:
-                    yield r
-                inr1 = self._r1.__contains__
-                for r in self._r2:
-                    if not inr1(r):
-                        yield r
-            return arbitraryordergen()
-        # try to use our own fast iterator if it exists
-        self._trysetasclist()
-        if self._ascending:
-            attr = 'fastasc'
-        else:
-            attr = 'fastdesc'
-        it = getattr(self, attr)
-        if it is not None:
-            return it()
-        # maybe half of the component supports fast
-        # get iterator for _r1
-        iter1 = getattr(self._r1, attr)
-        if iter1 is None:
-            # let's avoid side effect (not sure it matters)
-            iter1 = iter(sorted(self._r1, reverse=not self._ascending))
-        else:
-            iter1 = iter1()
-        # get iterator for _r2
-        iter2 = getattr(self._r2, attr)
-        if iter2 is None:
-            # let's avoid side effect (not sure it matters)
-            iter2 = iter(sorted(self._r2, reverse=not self._ascending))
-        else:
-            iter2 = iter2()
-        return _iterordered(self._ascending, iter1, iter2)
-
-    def _trysetasclist(self):
-        """populate the _asclist attribute if possible and necessary"""
-        if self._genlist is not None and self._asclist is None:
-            self._asclist = sorted(self._genlist)
-
-    @property
-    def fastasc(self):
-        self._trysetasclist()
-        if self._asclist is not None:
-            return self._asclist.__iter__
-        iter1 = self._r1.fastasc
-        iter2 = self._r2.fastasc
-        if None in (iter1, iter2):
-            return None
-        return lambda: _iterordered(True, iter1(), iter2())
-
-    @property
-    def fastdesc(self):
-        self._trysetasclist()
-        if self._asclist is not None:
-            return self._asclist.__reversed__
-        iter1 = self._r1.fastdesc
-        iter2 = self._r2.fastdesc
-        if None in (iter1, iter2):
-            return None
-        return lambda: _iterordered(False, iter1(), iter2())
-
-    def __contains__(self, x):
-        return x in self._r1 or x in self._r2
-
-    def sort(self, reverse=False):
-        """Sort the added set
-
-        For this we use the cached list with all the generated values and if we
-        know they are ascending or descending we can sort them in a smart way.
-        """
-        self._ascending = not reverse
-
-    def isascending(self):
-        return self._ascending is not None and self._ascending
-
-    def isdescending(self):
-        return self._ascending is not None and not self._ascending
-
-    def istopo(self):
-        # not worth the trouble asserting if the two sets combined are still
-        # in topographical order. Use the sort() predicate to explicitly sort
-        # again instead.
-        return False
-
-    def reverse(self):
-        if self._ascending is None:
-            self._list.reverse()
-        else:
-            self._ascending = not self._ascending
-
-    def first(self):
-        for x in self:
-            return x
-        return None
-
-    def last(self):
-        self.reverse()
-        val = self.first()
-        self.reverse()
-        return val
-
-    def __repr__(self):
-        d = {None: '', False: '-', True: '+'}[self._ascending]
-        return '<%s%s %r, %r>' % (type(self).__name__, d, self._r1, self._r2)
-
-class generatorset(abstractsmartset):
-    """Wrap a generator for lazy iteration
-
-    Wrapper structure for generators that provides lazy membership and can
-    be iterated more than once.
-    When asked for membership it generates values until either it finds the
-    requested one or has gone through all the elements in the generator
-    """
-    def __init__(self, gen, iterasc=None):
-        """
-        gen: a generator producing the values for the generatorset.
-        """
-        self._gen = gen
-        self._asclist = None
-        self._cache = {}
-        self._genlist = []
-        self._finished = False
-        self._ascending = True
-        if iterasc is not None:
-            if iterasc:
-                self.fastasc = self._iterator
-                self.__contains__ = self._asccontains
-            else:
-                self.fastdesc = self._iterator
-                self.__contains__ = self._desccontains
-
-    def __nonzero__(self):
-        # Do not use 'for r in self' because it will enforce the iteration
-        # order (default ascending), possibly unrolling a whole descending
-        # iterator.
-        if self._genlist:
-            return True
-        for r in self._consumegen():
-            return True
-        return False
-
-    def __contains__(self, x):
-        if x in self._cache:
-            return self._cache[x]
-
-        # Use new values only, as existing values would be cached.
-        for l in self._consumegen():
-            if l == x:
-                return True
-
-        self._cache[x] = False
-        return False
-
-    def _asccontains(self, x):
-        """version of contains optimised for ascending generator"""
-        if x in self._cache:
-            return self._cache[x]
-
-        # Use new values only, as existing values would be cached.
-        for l in self._consumegen():
-            if l == x:
-                return True
-            if l > x:
-                break
-
-        self._cache[x] = False
-        return False
-
-    def _desccontains(self, x):
-        """version of contains optimised for descending generator"""
-        if x in self._cache:
-            return self._cache[x]
-
-        # Use new values only, as existing values would be cached.
-        for l in self._consumegen():
-            if l == x:
-                return True
-            if l < x:
-                break
-
-        self._cache[x] = False
-        return False
-
-    def __iter__(self):
-        if self._ascending:
-            it = self.fastasc
-        else:
-            it = self.fastdesc
-        if it is not None:
-            return it()
-        # we need to consume the iterator
-        for x in self._consumegen():
-            pass
-        # recall the same code
-        return iter(self)
-
-    def _iterator(self):
-        if self._finished:
-            return iter(self._genlist)
-
-        # We have to use this complex iteration strategy to allow multiple
-        # iterations at the same time. We need to be able to catch revision
-        # removed from _consumegen and added to genlist in another instance.
-        #
-        # Getting rid of it would provide an about 15% speed up on this
-        # iteration.
-        genlist = self._genlist
-        nextrev = self._consumegen().next
-        _len = len # cache global lookup
-        def gen():
-            i = 0
-            while True:
-                if i < _len(genlist):
-                    yield genlist[i]
-                else:
-                    yield nextrev()
-                i += 1
-        return gen()
-
-    def _consumegen(self):
-        cache = self._cache
-        genlist = self._genlist.append
-        for item in self._gen:
-            cache[item] = True
-            genlist(item)
-            yield item
-        if not self._finished:
-            self._finished = True
-            asc = self._genlist[:]
-            asc.sort()
-            self._asclist = asc
-            self.fastasc = asc.__iter__
-            self.fastdesc = asc.__reversed__
-
-    def __len__(self):
-        for x in self._consumegen():
-            pass
-        return len(self._genlist)
-
-    def sort(self, reverse=False):
-        self._ascending = not reverse
-
-    def reverse(self):
-        self._ascending = not self._ascending
-
-    def isascending(self):
-        return self._ascending
-
-    def isdescending(self):
-        return not self._ascending
-
-    def istopo(self):
-        # not worth the trouble asserting if the two sets combined are still
-        # in topographical order. Use the sort() predicate to explicitly sort
-        # again instead.
-        return False
-
-    def first(self):
-        if self._ascending:
-            it = self.fastasc
-        else:
-            it = self.fastdesc
-        if it is None:
-            # we need to consume all and try again
-            for x in self._consumegen():
-                pass
-            return self.first()
-        return next(it(), None)
-
-    def last(self):
-        if self._ascending:
-            it = self.fastdesc
-        else:
-            it = self.fastasc
-        if it is None:
-            # we need to consume all and try again
-            for x in self._consumegen():
-                pass
-            return self.first()
-        return next(it(), None)
-
-    def __repr__(self):
-        d = {False: '-', True: '+'}[self._ascending]
-        return '<%s%s>' % (type(self).__name__, d)
-
-class spanset(abstractsmartset):
-    """Duck type for baseset class which represents a range of revisions and
-    can work lazily and without having all the range in memory
-
-    Note that spanset(x, y) behave almost like xrange(x, y) except for two
-    notable points:
-    - when x < y it will be automatically descending,
-    - revision filtered with this repoview will be skipped.
-
-    """
-    def __init__(self, repo, start=0, end=None):
-        """
-        start: first revision included the set
-               (default to 0)
-        end:   first revision excluded (last+1)
-               (default to len(repo)
-
-        Spanset will be descending if `end` < `start`.
-        """
-        if end is None:
-            end = len(repo)
-        self._ascending = start <= end
-        if not self._ascending:
-            start, end = end + 1, start +1
-        self._start = start
-        self._end = end
-        self._hiddenrevs = repo.changelog.filteredrevs
-
-    def sort(self, reverse=False):
-        self._ascending = not reverse
-
-    def reverse(self):
-        self._ascending = not self._ascending
-
-    def istopo(self):
-        # not worth the trouble asserting if the two sets combined are still
-        # in topographical order. Use the sort() predicate to explicitly sort
-        # again instead.
-        return False
-
-    def _iterfilter(self, iterrange):
-        s = self._hiddenrevs
-        for r in iterrange:
-            if r not in s:
-                yield r
-
-    def __iter__(self):
-        if self._ascending:
-            return self.fastasc()
-        else:
-            return self.fastdesc()
-
-    def fastasc(self):
-        iterrange = xrange(self._start, self._end)
-        if self._hiddenrevs:
-            return self._iterfilter(iterrange)
-        return iter(iterrange)
-
-    def fastdesc(self):
-        iterrange = xrange(self._end - 1, self._start - 1, -1)
-        if self._hiddenrevs:
-            return self._iterfilter(iterrange)
-        return iter(iterrange)
-
-    def __contains__(self, rev):
-        hidden = self._hiddenrevs
-        return ((self._start <= rev < self._end)
-                and not (hidden and rev in hidden))
-
-    def __nonzero__(self):
-        for r in self:
-            return True
-        return False
-
-    def __len__(self):
-        if not self._hiddenrevs:
-            return abs(self._end - self._start)
-        else:
-            count = 0
-            start = self._start
-            end = self._end
-            for rev in self._hiddenrevs:
-                if (end < rev <= start) or (start <= rev < end):
-                    count += 1
-            return abs(self._end - self._start) - count
-
-    def isascending(self):
-        return self._ascending
-
-    def isdescending(self):
-        return not self._ascending
-
-    def first(self):
-        if self._ascending:
-            it = self.fastasc
-        else:
-            it = self.fastdesc
-        for x in it():
-            return x
-        return None
-
-    def last(self):
-        if self._ascending:
-            it = self.fastdesc
-        else:
-            it = self.fastasc
-        for x in it():
-            return x
-        return None
-
-    def __repr__(self):
-        d = {False: '-', True: '+'}[self._ascending]
-        return '<%s%s %d:%d>' % (type(self).__name__, d,
-                                 self._start, self._end - 1)
-
-class fullreposet(spanset):
-    """a set containing all revisions in the repo
-
-    This class exists to host special optimization and magic to handle virtual
-    revisions such as "null".
-    """
-
-    def __init__(self, repo):
-        super(fullreposet, self).__init__(repo)
-
-    def __and__(self, other):
-        """As self contains the whole repo, all of the other set should also be
-        in self. Therefore `self & other = other`.
-
-        This boldly assumes the other contains valid revs only.
-        """
-        # other not a smartset, make is so
-        if not util.safehasattr(other, 'isascending'):
-            # filter out hidden revision
-            # (this boldly assumes all smartset are pure)
-            #
-            # `other` was used with "&", let's assume this is a set like
-            # object.
-            other = baseset(other - self._hiddenrevs)
-
-        other.sort(reverse=self.isdescending())
-        return other
-
-def prettyformatset(revs):
-    lines = []
-    rs = repr(revs)
-    p = 0
-    while p < len(rs):
-        q = rs.find('<', p + 1)
-        if q < 0:
-            q = len(rs)
-        l = rs.count('<', 0, p) - rs.count('>', 0, p)
-        assert l >= 0
-        lines.append((l, rs[p:q].rstrip()))
-        p = q
-    return '\n'.join('  ' * l + s for l, s in lines)
-
 def loadpredicate(ui, extname, registrarobj):
     """Load revset predicates from specified registrarobj
     """