def node_to_mql(e, node, visited_nodes):
mql_query = {}
num_relations = 0
visited_nodes.add(node)
for relation, dest in e.iter_edges(node):
if not dest in visited_nodes:
relation = format_mql_uri(relation)
if isnode(dest):
dest_mql = node_to_mql(e, dest, visited_nodes)
if type(dest_mql) == dict:
dest_mql = [dest_mql]
mql_query[relation] = dest_mql
else:
mql_query[relation] = adapt_mql(dest)
num_relations += 1
for relation, dest in iter_incoming_edges(e, node, visited_nodes):
if not dest in visited_nodes:
relation = '!' + format_mql_uri(relation)
if isnode(dest):
dest_mql = node_to_mql(e, dest, visited_nodes)
if type(dest_mql) == dict:
dest_mql = [dest_mql]
mql_query[relation] = dest_mql
else:
mql_query[relation] = adapt_mql(dest)
num_relations += 1
if num_relations == 0:
return None
return mql_query
def node_to_mql(e, node, visited_nodes):
mql_query = {}
num_relations = 0
visited_nodes.add(node)
for relation, dest in e.iter_edges(node):
if not dest in visited_nodes:
relation = format_mql_uri(relation)
if isnode(dest):
dest_mql = node_to_mql(e, dest, visited_nodes)
if type(dest_mql) == dict:
dest_mql = [dest_mql]
mql_query[relation] = dest_mql
else:
mql_query[relation] = adapt_mql(dest)
num_relations += 1
for relation, dest in iter_incoming_edges(e, node, visited_nodes):
if not dest in visited_nodes:
relation = '!' + format_mql_uri(relation)
if isnode(dest):
dest_mql = node_to_mql(e, dest, visited_nodes)
if type(dest_mql) == dict:
dest_mql = [dest_mql]
mql_query[relation] = dest_mql
else:
mql_query[relation] = adapt_mql(dest)
num_relations += 1
if num_relations == 0:
return None
return mql_query
def generate_mql(e):
"""
Generates a MQL query for the `Expression` `e`.
"""
start = choose_start_node(e)
graph = to_bidirected_graph(e)
generated = {}
for node in post_order_depth_first(graph, start):
d = {}
for relation, other in graph[node]:
if isnode(other):
try:
other = generated[other]
except KeyError:
continue # other is not in post_order_depth_first order
d[relation] = other
generated[node] = [d]
mql_query = json.dumps(generated[start],
sort_keys=True,
indent=2,
separators=(',', ': '))
mql_query = _tidy(mql_query)
target = paths_from_root(graph, start)[e.get_head()]
return target, mql_query
def to_bidirected_graph(e):
"""
Rewrite the graph such that there are reversed edges for every forward
edge.
If an edge goes into a data, it should not be reversed.
"""
graph = {node: [] for node in e.iter_nodes()}
for node in e.iter_nodes():
for relation, other in e.iter_edges(node):
relation = safely_to_unicode(relation)
if isnode(other):
graph[other].append((u"!" + relation, node))
else:
other = safely_to_unicode(other)
graph[node].append((relation, other))
assert all(isnode(x) for x in graph) and len(e) == len(graph)
return graph
def to_bidirected_graph(e):
"""
Rewrite the graph such that there are reversed edges for every forward
edge.
If an edge goes into a data, it should not be reversed.
"""
graph = {node: [] for node in e.iter_nodes()}
for node in e.iter_nodes():
for relation, other in e.iter_edges(node):
relation = safely_to_unicode(relation)
if isnode(other):
graph[other].append((u"!" + relation, node))
else:
other = safely_to_unicode(other)
graph[node].append((relation, other))
assert all(isnode(x) for x in graph) and len(e) == len(graph)
return graph
def adapt(x):
if isnode(x):
x = "?x{}".format(x)
return x
if isinstance(x, str):
assert_valid_encoding(x)
if x.startswith("\"") or ":" in x:
return x
return '"{}"'.format(x)
return str(x)
def adapt(x):
if isnode(x):
x = u"?x{}".format(x)
return x
if isinstance(x, basestring):
assert_valid_encoding(x)
if x.startswith(u"\"") or ":" in x:
return x
return u'"{}"'.format(x)
return unicode(x)
def adapt(x):
if isnode(x):
x = u"?x{}".format(x)
return x
if isinstance(x, basestring):
assert_valid_encoding(x)
if x.startswith(u"\"") or ":" in x:
return x
return u'"{}"'.format(x)
return unicode(x)
def adapt(x):
if isnode(x):
x = u"x{}".format(x)
return x
if isinstance(x, basestring):
assert_valid_encoding(x)
x = escape(x)
if x.startswith(u'"'):
return x
return u'"{}"'.format(x)
return unicode(x)
def test_acyclic(self):
head = self.e.get_head()
q = [head]
seen = set()
while q:
current = q.pop()
self.assertNotIn(current, seen)
seen.add(current)
for relation, child in self.e.iter_edges(current):
if isnode(child):
q.append(child)
def test_acyclic(self):
head = self.e.get_head()
q = [head]
seen = set()
while q:
current = q.pop()
self.assertNotIn(current, seen)
seen.add(current)
for relation, child in self.e.iter_edges(current):
if isnode(child):
q.append(child)
def make_canonical_expression(e):
i = 0
q = [e.get_head()]
seen = set()
while i != len(q):
node = q[i]
i += 1
assert node not in seen, "Nouuu, expression is cyclic!"
for relation, child in e.iter_edges(node):
if isnode(child):
q.append(child)
q.reverse()
canon = {}
for node in q:
childs = []
for label, child in e.iter_edges(node):
if isnode(child):
child = canon[child]
childs.append((label, child))
childs.sort()
canon[node] = tuple(childs)
return canon[e.get_head()]
def make_canonical_expression(e):
i = 0
q = [e.get_head()]
seen = set()
while i != len(q):
node = q[i]
i += 1
assert node not in seen, "Nouuu, expression is cyclic!"
for relation, child in e.iter_edges(node):
if isnode(child):
q.append(child)
q.reverse()
canon = {}
for node in q:
childs = []
for label, child in e.iter_edges(node):
if isnode(child):
child = canon[child]
childs.append((label, child))
childs.sort()
canon[node] = tuple(childs)
return canon[e.get_head()]
def paths_from_root(graph, start):
"""
Generates paths from `start` to every other node in `graph` and puts it in
the returned dictionary `paths`.
ie.: `paths_from_node(graph, start)[node]` is a list of the edge names used
to get to `node` form `start`.
"""
paths = {start: []}
q = [start]
seen = set()
while q:
node = q.pop()
seen.add(node)
for relation, child in graph[node]:
if isnode(child) and child not in seen:
q.append(child)
paths[child] = paths[node] + [relation]
return paths
def paths_from_root(graph, start):
"""
Generates paths from `start` to every other node in `graph` and puts it in
the returned dictionary `paths`.
ie.: `paths_from_node(graph, start)[node]` is a list of the edge names used
to get to `node` form `start`.
"""
paths = {start: []}
q = [start]
seen = set()
while q:
node = q.pop()
seen.add(node)
for relation, child in graph[node]:
if isnode(child) and child not in seen:
q.append(child)
paths[child] = paths[node] + [relation]
return paths
def post_order_depth_first(graph, start):
"""
Iterate over the nodes of the graph (is a tree) in a way such that every
node is preceded by it's childs.
`graph` is a dict that represents the `Expression` graph. It's a tree too
beacuse Expressions are trees.
`start` is the node to use as the root of the tree.
"""
q = [start]
seen = set()
i = 0
while i != len(graph):
node = q[i]
seen.add(node)
i += 1
for _, other in graph[node]:
if isnode(other) and other not in seen:
q.append(other)
assert len(q) == len(graph)
q.reverse()
return q
def post_order_depth_first(graph, start):
"""
Iterate over the nodes of the graph (is a tree) in a way such that every
node is preceded by it's childs.
`graph` is a dict that represents the `Expression` graph. It's a tree too
beacuse Expressions are trees.
`start` is the node to use as the root of the tree.
"""
q = [start]
seen = set()
i = 0
while i != len(graph):
node = q[i]
seen.add(node)
i += 1
for _, other in graph[node]:
if isnode(other) and other not in seen:
q.append(other)
assert len(q) == len(graph)
q.reverse()
return q
def generate_mql(e):
"""
Generates a MQL query for the `Expression` `e`.
"""
start = choose_start_node(e)
graph = to_bidirected_graph(e)
generated = {}
for node in post_order_depth_first(graph, start):
d = {}
for relation, other in graph[node]:
if isnode(other):
try:
other = generated[other]
except KeyError:
continue # other is not in post_order_depth_first order
d[relation] = other
generated[node] = [d]
mql_query = json.dumps(generated[start], sort_keys=True,
indent=2, separators=(',', ': '))
mql_query = _tidy(mql_query)
target = paths_from_root(graph, start)[e.get_head()]
return target, mql_query