| Index: third_party/logilab/common/visitor.py
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| diff --git a/third_party/logilab/common/visitor.py b/third_party/logilab/common/visitor.py
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| new file mode 100644
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| index 0000000000000000000000000000000000000000..802d2befced41e4574243f02e8f6ef202e7859eb
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| --- /dev/null
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| +++ b/third_party/logilab/common/visitor.py
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| @@ -0,0 +1,107 @@
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| +# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
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| +# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
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| +#
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| +# This file is part of logilab-common.
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| +#
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| +# logilab-common is free software: you can redistribute it and/or modify it under
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| +# the terms of the GNU Lesser General Public License as published by the Free
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| +# Software Foundation, either version 2.1 of the License, or (at your option) any
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| +# later version.
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| +#
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| +# logilab-common is distributed in the hope that it will be useful, but WITHOUT
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| +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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| +# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
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| +# details.
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| +#
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| +# You should have received a copy of the GNU Lesser General Public License along
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| +# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
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| +"""A generic visitor abstract implementation.
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| +
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| +
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| +
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| +
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| +"""
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| +__docformat__ = "restructuredtext en"
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| +
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| +def no_filter(_):
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| +    return 1
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| +
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| +# Iterators ###################################################################
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| +class FilteredIterator(object):
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| +
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| +    def __init__(self, node, list_func, filter_func=None):
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| +        self._next = [(node, 0)]
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| +        if filter_func is None:
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| +            filter_func = no_filter
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| +        self._list = list_func(node, filter_func)
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| +
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| +    def next(self):
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| +        try:
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| +            return self._list.pop(0)
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| +        except :
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| +            return None
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| +
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| +# Base Visitor ################################################################
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| +class Visitor(object):
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| +
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| +    def __init__(self, iterator_class, filter_func=None):
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| +        self._iter_class = iterator_class
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| +        self.filter = filter_func
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| +
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| +    def visit(self, node, *args, **kargs):
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| +        """
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| +        launch the visit on a given node
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| +
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| +        call 'open_visit' before the beginning of the visit, with extra args
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| +        given
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| +        when all nodes have been visited, call the 'close_visit' method
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| +        """
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| +        self.open_visit(node, *args, **kargs)
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| +        return self.close_visit(self._visit(node))
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| +
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| +    def _visit(self, node):
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| +        iterator = self._get_iterator(node)
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| +        n = iterator.next()
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| +        while n:
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| +            result = n.accept(self)
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| +            n = iterator.next()
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| +        return result
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| +
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| +    def _get_iterator(self, node):
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| +        return self._iter_class(node, self.filter)
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| +
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| +    def open_visit(self, *args, **kargs):
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| +        """
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| +        method called at the beginning of the visit
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| +        """
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| +        pass
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| +
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| +    def close_visit(self, result):
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| +        """
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| +        method called at the end of the visit
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| +        """
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| +        return result
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| +
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| +# standard visited mixin ######################################################
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| +class VisitedMixIn(object):
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| +    """
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| +    Visited interface allow node visitors to use the node
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| +    """
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| +    def get_visit_name(self):
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| +        """
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| +        return the visit name for the mixed class. When calling 'accept', the
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| +        method <'visit_' + name returned by this method> will be called on the
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| +        visitor
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| +        """
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| +        try:
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| +            return self.TYPE.replace('-', '_')
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| +        except:
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| +            return self.__class__.__name__.lower()
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| +
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| +    def accept(self, visitor, *args, **kwargs):
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| +        func = getattr(visitor, 'visit_%s' % self.get_visit_name())
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| +        return func(self, *args, **kwargs)
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| +
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| +    def leave(self, visitor, *args, **kwargs):
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| +        func = getattr(visitor, 'leave_%s' % self.get_visit_name())
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| +        return func(self, *args, **kwargs)
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| 
 |