comparison mercurial/revset.py @ 20749:c3e49b127de0

revset: added _orderedsetmixin class

This class has utility methods for any ordered class to get the min and the
max values.

20748:6b731b29e154

        boolean.

        This is part of the mandatory API for smartset."""
        return lazyset(self, condition)

class lazyset(object):
    """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
    """

20749:c3e49b127de0

        boolean.

        This is part of the mandatory API for smartset."""
        return lazyset(self, condition)

class _orderedsetmixin(object):
    """Mixin class with utility methods for smartsets

    This should be extended by smartsets which have the isascending(),
    isdescending() and reverse() methods"""

    def _first(self):
        """return the first revision in the set"""
        for r in self:
            return r
        return None

    def _last(self):
        """return the last revision in the set"""
        self.reverse()
        m = self._first()
        self.reverse()
        return m

    def min(self):
        """return the smallest element in the set"""
        if self.isascending():
            return self._first()
        return self._last()

    def max(self):
        """return the largest element in the set"""
        if self.isascending():
            return self._last()
        return self._first()

class lazyset(object):
    """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
    """