def append(child):
if isinstance(child, Matcher):
if isinstance(child, Delayed):
child.assert_matcher()
pending.append(child.matcher)
stack.append((child, empty()))
else:
stack.append((child, iter(child)))
def append(child):
if isinstance(child, Matcher):
if isinstance(child, Delayed):
child.assert_matcher()
pending.append(child.matcher)
stack.append((child, empty()))
else:
stack.append((child, iter(child)))
def _match(self, stream):
'''
Attempt to match the stream.
'''
if not self.__first:
self.__counter += 1
if self.__curtail(self.__counter, stream):
return empty()
else:
cache = PerCallCache(self.__matcher._match(stream))
if self.__first is None:
self.__first = cache
return cache.generator()
else:
return self.__first.view()
def _match(self, stream):
'''
Attempt to match the stream.
'''
if not self.__first:
self.__counter += 1
if self.__curtail(self.__counter, stream):
return empty()
else:
cache = PerCallCache(self.__matcher._match(stream))
if self.__first is None:
self.__first = cache
return cache.generator()
else:
return self.__first.view()
def dfs_edges(node, type_):
'''
Iterative DFS, based on http://www.ics.uci.edu/~eppstein/PADS/DFS.py
Returns forward and reverse edges. Also returns root node in correct
order for pre- (FORWARD) and post- (BACKWARD) ordering.
``type_`` selects which values are iterated over. Children which are
not of this type are flagged with LEAF.
'''
while isinstance(node, type_):
try:
stack = [(node, iter(node), ROOT)]
yield node, node, FORWARD | ROOT
visited = set()
visited = fallback_add(visited, node)
while stack:
parent, children, p_type = stack[-1]
try:
child = next(children)
if isinstance(child, type_):
if safe_in(child, visited, False):
yield parent, child, NON_TREE
else:
stack.append((child, iter(child), NODE))
yield parent, child, FORWARD | NODE
visited = fallback_add(visited, child)
else:
stack.append((child, empty(), LEAF))
yield parent, child, FORWARD | LEAF
except StopIteration:
stack.pop()
if stack:
yield stack[-1][0], parent, BACKWARD | p_type
yield node, node, BACKWARD | ROOT
return
except Reset:
yield # in response to the throw (ignored by caller)
def dfs_edges(node, type_):
'''
Iterative DFS, based on http://www.ics.uci.edu/~eppstein/PADS/DFS.py
Returns forward and reverse edges. Also returns root node in correct
order for pre- (FORWARD) and post- (BACKWARD) ordering.
``type_`` selects which values are iterated over. Children which are
not of this type are flagged with LEAF.
'''
while isinstance(node, type_):
try:
stack = [(node, iter(node), ROOT)]
yield node, node, FORWARD | ROOT
visited = set()
safe_add(visited, node) # cannot track loops in unhashable objects
while stack:
parent, children, ptype = stack[-1]
try:
child = next(children)
if isinstance(child, type_):
if safe_in(child, visited, False):
yield parent, child, NONTREE
else:
stack.append((child, iter(child), NODE))
yield parent, child, FORWARD | NODE
safe_add(visited, child)
else:
stack.append((child, empty(), LEAF))
yield parent, child, FORWARD | LEAF
except StopIteration:
stack.pop()
if stack:
yield stack[-1][0], parent, BACKWARD | ptype
yield node, node, BACKWARD | ROOT
return
except Reset:
yield # in response to the throw (ignored by caller)