def inject_remove_node(self, lhs_node_id):
"""Inject a new node removal to the rule.
This method removes from `p` all the nodes that map
to the node with the id `lhs_node_id`. In addition,
all the nodes from `rhs` that are mapped by the nodes
removed in `p` are also removed.
Parameters
----------
lhs_node_id
Id of the node in `lhs` that should be removed
by the rule.
"""
# remove corresponding nodes from p and rhs
p_keys = keys_by_value(self.p_lhs, lhs_node_id)
for k in p_keys:
if k in self.p.nodes():
primitives.remove_node(self.p, k)
if self.p_rhs[k] in self.rhs.nodes():
primitives.remove_node(self.rhs, self.p_rhs[k])
affected_nodes = keys_by_value(self.p_rhs, self.p_rhs[k])
for node in affected_nodes:
del self.p_rhs[node]
del self.p_lhs[k]
return
def added_edge_attrs(self):
"""Get edge attributes added by the rule.
Returns
-------
attrs : dict
Dictionary where keys are edges from `rhs`
and values are attribute dictionaries to add.
"""
attrs = dict()
for s, t in self.rhs.edges():
s_p_nodes = keys_by_value(self.p_rhs, s)
t_p_nodes = keys_by_value(self.p_rhs, t)
new_attrs = {}
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) in self.p.edges():
new_attrs = attrs_union(
new_attrs,
dict_sub(
self.rhs.edge[s][t],
self.p.edge[s_p_node][t_p_node]
)
)
return attrs
def _remove_edge_rhs(self, node1, node2):
"""Remove edge from the rhs of the graph."""
primitives.remove_edge(self.rhs, node1, node2)
for pn1 in keys_by_value(self.p_rhs, node1):
for pn2 in keys_by_value(self.p_rhs, node2):
if (pn1, pn2) in self.p.edges():
primitives.remove_edge(self.p, pn1, pn2)
def merge_nodes(self, n1, n2, node_id=None):
"""Merge two nodes of the graph."""
# Update graphs
new_name = None
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
nodes_to_merge = set()
for k1 in p_keys_1:
if k1 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in the "
"preserved part of the rule" % k1
)
for k2 in p_keys_2:
if k2 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in "
"the preserved part of the rule" % k2
)
nodes_to_merge.add(self.p_rhs[k1])
nodes_to_merge.add(self.p_rhs[k2])
new_name = primitives.merge_nodes(
self.rhs,
list(nodes_to_merge),
node_id=node_id
)
# Update mappings
keys = p_keys_1 + p_keys_2
for k in keys:
self.p_rhs[k] = new_name
return new_name
def removed_edge_attrs(self):
"""Get edge attributes removed by the rule.
Returns
-------
attrs : dict
Dictionary where keys are edges from `lhs`
and values are attribute dictionaries to remove.
"""
attrs = dict()
for s, t in self.lhs.edges():
s_p_nodes = keys_by_value(self.p_lhs, s)
t_p_nodes = keys_by_value(self.p_lhs, t)
new_attrs = {}
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) in self.p.edges():
new_attrs = attrs_union(
new_attrs,
dict_sub(
self.lhs.edge[s][t],
self.p.edge[s_p_node][t_p_node]
)
)
if len(new_attrs) > 0:
attrs[(s, t)] = new_attrs
return attrs
def get_unique_map_to_pullback_complement_full(a_p, p_c, a_prime_a, a_prime_z,
z_c):
"""Find morphism z->p using the UP of PBC."""
# Preliminary checks
if not is_monic(a_p):
raise ReGraphError("Morphism 'a_p' is required to be a mono "
"to use the UP of the pullback complement")
z_p = {}
for z_element, c_element in z_c.items():
a_prime_elements = keys_by_value(a_prime_z, z_element)
p_elements1 = set() # candidate p elements
for a_prime_element in a_prime_elements:
p_elements1.add(a_p[a_prime_a[a_prime_element]])
# resolve ambiguity going the other way
p_elements2 = keys_by_value(p_c, c_element)
if len(p_elements1) == 0:
if len(p_elements2) == 1:
z_p[z_element] = list(p_elements2)[0]
else:
raise ValueError("Something is wrong")
else:
intersection = p_elements1.intersection(p_elements2)
if len(intersection) == 1:
z_p[z_element] = list(intersection)[0]
else:
raise ValueError("Something is wrong")
return z_p
def remove_edge_rhs(self, node1, node2):
"""Remove edge from the rhs of the graph."""
primitives.remove_edge(self.rhs, node1, node2)
for pn1 in keys_by_value(self.p_rhs, node1):
for pn2 in keys_by_value(self.p_rhs, node2):
print(pn1, pn2)
try:
primitives.remove_edge(self.p, pn1, pn2)
except GraphError:
continue
def removed_edges(self):
"""."""
edges = set()
for s, t in self.lhs.edges():
s_p_nodes = keys_by_value(self.p_lhs, s)
t_p_nodes = keys_by_value(self.p_lhs, t)
if len(s_p_nodes) != 0 and len(t_p_nodes) != 0:
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) not in self.p.edges():
edges.add((s_p_node, t_p_node))
return edges
def subtract(a, b, ba_mapping):
"""Subtract graphs provided node mapping.
Subtract graph B from A having mapping of nodes from B to
nodes from A specified.
Parameters
----------
a : networkx.(Di)Graph
b : networkx.(Di)Graph
ba_mapping : dict
Returns
-------
Graph representing the difference a - b.
Examples
--------
>>> a = nx.DiGraph()
>>> add_nodes_from(a, [1, 2, 3])
>>> add_edges_from(a, [(1, 2), (2, 2), (2, 3)])
>>> b = nx.DiGraph()
>>> add_nodes_from(b, ['x', 'y'])
>>> ba_mapping = {'x': 1, 'y': 3}
>>> diff = subtract(a, b, ba_mapping)
>>> diff.nodes()
[2]
>>> diff.edges()
[(2, 2)]
"""
res = type(a)()
f = ba_mapping
for n in a.nodes():
if n not in f.values():
add_node(res,
n,
a.node[n])
for (n1, n2) in a.edges():
if n1 in res.nodes() and n2 in res.nodes():
b_keys_1 = keys_by_value(f, n1)
b_keys_2 = keys_by_value(f, n2)
if len(b_keys_1) == 0 or len(b_keys_2) == 0:
add_edge(res, n1, n2, get_edge(a, n1, n2))
else:
for k1 in b_keys_1:
for k2 in b_keys_2:
if (k1, k2) not in b.edges():
add_edge(res,
n1,
n2,
get_edge(a, n1, n2))
return res
def subtract(a, b, ba_mapping):
"""Subtract graphs provided node mapping.
Subtract graph B from A having mapping of nodes from B to
nodes from A specified.
Parameters
----------
a : networkx.(Di)Graph
b : networkx.(Di)Graph
ba_mapping : dict
Returns
-------
Graph representing the difference a - b.
Examples
--------
>>> a = nx.DiGraph()
>>> add_nodes_from(a, [1, 2, 3])
>>> add_edges_from(a, [(1, 2), (2, 2), (2, 3)])
>>> b = nx.DiGraph()
>>> add_nodes_from(b, ['x', 'y'])
>>> ba_mapping = {'x': 1, 'y': 3}
>>> diff = subtract(a, b, ba_mapping)
>>> diff.nodes()
[2]
>>> diff.edges()
[(2, 2)]
"""
res = type(a)()
f = ba_mapping
for n in a.nodes():
if n not in f.values():
add_node(res,
n,
a.node[n])
for (n1, n2) in a.edges():
if n1 in res.nodes() and n2 in res.nodes():
b_keys_1 = keys_by_value(f, n1)
b_keys_2 = keys_by_value(f, n2)
if len(b_keys_1) == 0 or len(b_keys_2) == 0:
add_edge(res, n1, n2, get_edge(a, n1, n2))
else:
for k1 in b_keys_1:
for k2 in b_keys_2:
if (k1, k2) not in b.edges():
add_edge(res,
n1,
n2,
get_edge(a, n1, n2))
return res
def remove_node(self, n):
"""Remove a node in the graph."""
# remove corresponding nodes from p and rhs
p_keys = keys_by_value(self.p_lhs, n)
for k in p_keys:
if k in self.p.nodes():
primitives.remove_node(self.p, k)
if self.p_rhs[k] in self.rhs.nodes():
primitives.remove_node(self.rhs, self.p_rhs[k])
affected_nodes = keys_by_value(self.p_rhs, self.p_rhs[k])
for node in affected_nodes:
del self.p_rhs[node]
del self.p_lhs[k]
return
def inject_remove_edge(self, n1, n2):
"""Inject removal of an edge by the rule.
Parameters
----------
n1 : hashable
Id of an edge's source node in `lhs`.
n2 : hashable
Id of an edge's target node in `lhs`.
Raises
------
RuleError
If some of the nodes are not found in neither
`lhs` nor `p`, or if a corresponding edge in
`p` does not exist.
"""
# Find nodes in p mapping to n1 & n2
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
# n1 is actually a node from `p`
if len(p_keys_1) == 0:
if n1 in self.p.nodes():
p_keys_1 = [n1]
else:
raise RuleError(
"Node '%s' is not found in neither left-hand "
"side nor preserved part" % n2)
if len(p_keys_2) == 0:
if n2 in self.p.nodes():
p_keys_2 = [n2]
else:
raise RuleError(
"Node '%s' is not found in neither left-hand "
"side nor preserved part" % str(n2))
for k1 in p_keys_1:
for k2 in p_keys_2:
if (k1, k2) in self.p.edges():
primitives.remove_edge(self.p, k1, k2)
primitives.remove_edge(self.rhs, self.p_rhs[k1], self.p_rhs[k2])
else:
raise RuleError(
"Edge '%s->%s' does not exist in the preserved part"
% (k1, k2))
return
def remove_edge(self, n1, n2):
"""Remove edge from the graph."""
# Find nodes in p mapping to n1 & n2
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
# Remove edge from the preserved part & rhs of the rule
for k1 in p_keys_1:
if k1 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in "
"the preserved part" % k1
)
for k2 in p_keys_2:
if k2 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in "
"the preserved part" % k2
)
rhs_key_1 = self.p_rhs[k1]
rhs_key_2 = self.p_rhs[k2]
if self.p.is_directed():
if (k1, k2) not in self.p.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the preserved "
"part of the rule " % (k1, k2)
)
if (rhs_key_1, rhs_key_2) not in self.rhs.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the right hand "
"side of the rule " % (rhs_key_1, rhs_key_2)
)
primitives.remove_edge(self.p, k1, k2)
primitives.remove_edge(self.rhs, rhs_key_1, rhs_key_2)
else:
if (k1, k2) not in self.p.edges() and\
(k2, k1) not in self.p.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the "
"preserved part of the rule " % (k1, k2)
)
if (rhs_key_1, rhs_key_2) not in self.rhs.edges() and\
(rhs_key_2, rhs_key_1) not in self.rhs.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the right "
"hand side of the rule " % (rhs_key_1, rhs_key_2)
)
primitives.remove_edge(self.p, k1, k2)
return
def get_unique_map_to_pullback_complement(a_p, p_c, a_prime_a, a_prime_z, z_c):
"""Find morphism z->p using the UP of PBC."""
# Preliminary checks
if not is_monic(a_p):
raise ReGraphError("Morphism 'a_p' is required to be a mono "
"to use the UP of the pullback complement")
z_p = {}
for z_element, c_element in z_c.items():
a_prime_elements = keys_by_value(a_prime_z, z_element)
p_elements1 = set() # candidate p elements
for a_prime_element in a_prime_elements:
p_elements1.add(a_p[a_prime_a[a_prime_element]])
# resolve ambiguity going the other way
p_elements2 = keys_by_value(p_c, c_element)
if len(p_elements1) == 0:
if len(p_elements2) == 1:
z_p[z_element] = list(p_elements2)[0]
else:
raise ValueError(
"Cannot apply the universal property, " +
"check if the conditions to apply it are satisfied, " +
"problem: element '{}' from Z ".format(z_element) +
"corresponds to more than one element " +
"from P (i.e. corresponds to {}) and A'->A->P doesn't ".
format(p_elements2) + "resolve the conflict")
else:
intersection = p_elements1.intersection(p_elements2)
if len(intersection) == 1:
z_p[z_element] = list(intersection)[0]
elif len(intersection) == 0:
raise ValueError(
"Cannot apply the universal property, " +
"check if the conditions to apply it are satisfied, " +
"problem: element '{}' from Z ".format(z_element) +
"corresponds to '{}' ".format(p_elements1) +
"from P following A'->A->P ".format(intersection) +
"to '{}' following (P->C)^{{-1}} composed with (Z -> C)".
format(p_elements2))
else:
raise ValueError(
"Cannot apply the universal property, " +
"check if the conditions to apply it are satisfied, " +
"problem: element '{}' from Z ".format(z_element) +
"doesn't corresponds to exactly one element " +
"from P (i.e. corresponds to {}) in both A'->A->P ".format(
intersection) +
"and (P->C)^{{-1}} composed with (Z -> C)")
return z_p
def inject_update_node_attrs(self, n, attrs):
"""Inject an update of node attrs by the rule.
Parameters
----------
n : hashable
Id of a node from the left-hand side whose attrs
should be updated
attrs : dict
Dictionary of new attrs that will replace the old ones
Raises
------
RuleError
If node `n` does not exist in the left-hand side or
is being removed by the rule.
"""
if n not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the left hand "
"side of the rule" % n)
p_keys = keys_by_value(self.p_lhs, n)
if len(p_keys) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, "
"cannot update attributes" % n)
for k in p_keys:
self.p.node[k] = None
primitives.update_node_attrs(self.rhs, self.p_rhs[k], attrs)
return
def _refine_delta(self, delta):
lhs = delta["rule"].refine(self.graph, delta["lhs_instance"])
delta["lhs_instance"] = lhs
for n in delta["rule"].rhs.nodes():
if n not in delta["rhs_instance"].keys():
delta["rhs_instance"][n] = lhs[
delta["rule"].p_lhs[keys_by_value(delta["rule"].p_rhs, n)[0]]]
def _check_totality(hierarchy, graph_id, rule, instance, lhs_typing,
rhs_typing):
""""Check that everything is typed at the end of the rewriting."""
for node in rule.rhs.nodes():
p_nodes = keys_by_value(rule.p_rhs, node)
for typing_graph in hierarchy.successors(graph_id):
typing = hierarchy.edge[graph_id][typing_graph].mapping
# Totality can be broken in two cases
if len(p_nodes) > 1:
# node will be merged
all_untyped = True
for p_node in p_nodes:
if instance[rule.p_lhs[p_node]] in typing.keys():
all_untyped = False
break
if all_untyped:
continue
if typing_graph in rhs_typing.keys() and\
node in rhs_typing[typing_graph].keys():
continue
else:
raise RewritingError(
"Rewriting is strict (no propagation of types is "
"allowed), typing of the node `%s` "
"in rhs is required (typing by the following "
"graph stays unresolved: '%s')!" % (node, typing_graph))
def test_inject_clone_node(self):
pattern = nx.DiGraph()
prim.add_nodes_from(pattern, [1, 2, 3])
prim.add_edges_from(pattern, [(1, 2), (3, 2)])
rule = Rule.from_transform(pattern)
new_p_node, new_rhs_node = rule.inject_clone_node(2)
check_homomorphism(rule.p, rule.lhs, rule.p_lhs)
check_homomorphism(rule.p, rule.rhs, rule.p_rhs)
assert (new_p_node in rule.p.nodes())
assert (new_rhs_node in rule.rhs.nodes())
assert (rule.p_rhs[new_p_node] == new_rhs_node)
assert ((1, new_p_node) in rule.p.edges())
assert ((3, new_p_node) in rule.p.edges())
assert ((1, new_rhs_node) in rule.rhs.edges())
assert ((3, new_rhs_node) in rule.rhs.edges())
new_p_node, new_rhs_node = rule.inject_clone_node(2)
assert (len(keys_by_value(rule.p_lhs, 2)) == 3)
check_homomorphism(rule.p, rule.lhs, rule.p_lhs)
check_homomorphism(rule.p, rule.rhs, rule.p_rhs)
rule.inject_remove_node(3)
try:
rule.inject_clone_node(3)
raise ValueError("Cloning of removed node was not caught")
except:
pass
def add_node(self, node_id, attrs=None):
"""Add node to the graph.
Parameters
----------
node_id : hashable
Id of a node to add
attrs : dict, optional
Attributes of the node.
Raises
------
RuleError
If node with this id already exists in the `rhs`.
"""
if node_id not in self.rhs.nodes():
p_keys = keys_by_value(self.p_rhs, node_id)
# here we check for the nodes with the same name in the lhs
for k in p_keys:
lhs_key = self.p_lhs[k]
if lhs_key == node_id:
raise RuleError(
"Node with the id '%s' already exists in the "
"left hand side of the rule" %
node_id
)
primitives.add_node(self.rhs, node_id, attrs)
else:
raise RuleError(
"Node with the id '%s' already exists in the "
"right hand side of the rule" %
node_id
)
def _check_totality(hierarchy, graph_id, rule, instance,
lhs_typing, rhs_typing):
""""Check that everything is typed at the end of the rewriting."""
for node in rule.rhs.nodes():
p_nodes = keys_by_value(rule.p_rhs, node)
for typing_graph in hierarchy.successors(graph_id):
typing = hierarchy.edge[graph_id][typing_graph].mapping
# Totality can be broken in two cases
if len(p_nodes) > 1:
# node will be merged
all_untyped = True
for p_node in p_nodes:
if instance[rule.p_lhs[p_node]] in typing.keys():
all_untyped = False
break
if all_untyped:
continue
if typing_graph in rhs_typing.keys() and\
node in rhs_typing[typing_graph].keys():
continue
else:
raise RewritingError(
"Rewriting is strict (no propagation of types is "
"allowed), typing of the node `%s` "
"in rhs is required (typing by the following "
"graph stays unresolved: '%s')!" %
(node, typing_graph))
def get_unique_map(a, b, c, d, a_b, b_d, c_d):
"""Get a map a->c that makes a square commute."""
a_c = dict()
for node in b.nodes():
a_keys = keys_by_value(a_b, node)
if len(a_keys) > 0:
# node stayed in the rule
if node in b_d.keys():
d_node = b_d[node]
c_keys = keys_by_value(c_d, d_node)
if len(a_keys) != len(c_keys):
raise ReGraphError("Map is not unique!")
else:
for i, a_key in enumerate(a_keys):
a_c[a_key] = c_keys[i]
return a_c
def _autocomplete_typing(hierarchy, graph_id, instance, lhs_typing, p_typing,
rhs_typing_rel, p_lhs, p_rhs):
if lhs_typing is None:
new_lhs_typing = dict()
else:
new_lhs_typing = format_typing(lhs_typing)
if p_typing is None:
new_p_typing = dict()
else:
new_p_typing = normalize_typing_relation(p_typing)
if rhs_typing_rel is None:
new_rhs_typing_rel = dict()
else:
new_rhs_typing_rel = normalize_typing_relation(rhs_typing_rel)
successors = list(hierarchy.successors(graph_id))
if len(successors) > 0:
ancestors = hierarchy.get_descendants(graph_id)
for anc, anc_typing in ancestors.items():
if anc not in new_rhs_typing_rel.keys():
new_rhs_typing_rel[anc] = dict()
merged_nodes = set()
for r_node in p_rhs.values():
p_nodes = keys_by_value(p_rhs, r_node)
if len(p_nodes) > 1:
merged_nodes.add(r_node)
for typing_graph in hierarchy.successors(graph_id):
typing = hierarchy.typing[graph_id][typing_graph]
# Autocomplete lhs and rhs typings
# by immediate successors induced by an instance
if typing_graph not in new_lhs_typing.keys():
new_lhs_typing[typing_graph] = dict()
for (source, target) in instance.items():
if source not in new_lhs_typing[typing_graph].keys():
if target in typing.keys():
new_lhs_typing[typing_graph][source] = typing[target]
for (p_node, l_node) in p_lhs.items():
if l_node in new_lhs_typing[typing_graph].keys():
if p_rhs[p_node] not in new_rhs_typing_rel[
typing_graph].keys():
new_rhs_typing_rel[typing_graph][p_rhs[p_node]] = set()
new_rhs_typing_rel[typing_graph][p_rhs[p_node]].add(
new_lhs_typing[typing_graph][l_node])
# Second step of autocompletion of rhs typing
for graph, typing in new_rhs_typing_rel.items():
ancestors = hierarchy.get_descendants(graph)
for ancestor, ancestor_typing in ancestors.items():
dif = set(typing.keys()) -\
set(new_rhs_typing_rel[ancestor].keys())
for node in dif:
type_set = set()
for el in new_rhs_typing_rel[graph][node]:
type_set.add(ancestor_typing[el])
new_rhs_typing_rel[ancestor][node] = type_set
return (new_lhs_typing, new_p_typing, new_rhs_typing_rel)
def added_edges(self):
"""."""
edges = set()
for s, t in self.rhs.edges():
s_p_nodes = keys_by_value(self.p_rhs, s)
t_p_nodes = keys_by_value(self.p_rhs, t)
if len(s_p_nodes) == 0 or len(t_p_nodes) == 0:
edges.add((s, t))
else:
found_edge = False
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) in self.p.edges():
found_edge = True
if not found_edge:
edges.add((s, t))
return edges
def remove_node_rhs(self, n):
"""Remove a node from a rhs."""
p_keys = keys_by_value(self.p_rhs, n)
for p_node in p_keys:
primitives.remove_node(self.p, p_node)
del self.p_rhs[p_node]
del self.p_lhs[p_node]
primitives.remove_node(self.rhs, n)
def added_nodes(self):
"""A set of nodes from rhs which are added by a rule."""
nodes = set()
for r_node in self.rhs.nodes():
p_nodes = keys_by_value(self.p_rhs, r_node)
if len(p_nodes) == 0:
nodes.add(r_node)
return nodes
def removed_nodes(self):
"""."""
nodes = set()
for node in self.lhs.nodes():
p_nodes = keys_by_value(self.p_lhs, node)
if len(p_nodes) == 0:
nodes.add(node)
return nodes
def cloned_nodes(self):
"""."""
nodes = dict()
for node in self.lhs.nodes():
p_nodes = keys_by_value(self.p_lhs, node)
if len(p_nodes) > 1:
nodes[node] = set(p_nodes)
return nodes
def _autocomplete_typing(hierarchy, graph_id, instance,
lhs_typing, rhs_typing_rel, p_lhs, p_rhs):
successors = list(hierarchy.successors(graph_id))
if len(successors) > 0:
if lhs_typing is None:
new_lhs_typing = dict()
else:
new_lhs_typing = format_typing(lhs_typing)
if rhs_typing_rel is None:
new_rhs_typing_rel = dict()
else:
new_rhs_typing_rel = normalize_typing_relation(rhs_typing_rel)
ancestors = hierarchy.get_ancestors(graph_id)
for anc, anc_typing in ancestors.items():
if anc not in new_rhs_typing_rel.keys():
new_rhs_typing_rel[anc] = dict()
merged_nodes = set()
for r_node in p_rhs.values():
p_nodes = keys_by_value(p_rhs, r_node)
if len(p_nodes) > 1:
merged_nodes.add(r_node)
for typing_graph in hierarchy.successors(graph_id):
typing = hierarchy.typing[graph_id][typing_graph]
# Autocomplete lhs and rhs typings
# by immediate successors induced by an instance
if typing_graph not in new_lhs_typing.keys():
new_lhs_typing[typing_graph] = dict()
for (source, target) in instance.items():
if source not in new_lhs_typing[typing_graph].keys():
if target in typing.keys():
new_lhs_typing[typing_graph][source] = typing[target]
for (p_node, l_node) in p_lhs.items():
if l_node in new_lhs_typing[typing_graph].keys():
if p_rhs[p_node] not in new_rhs_typing_rel[typing_graph].keys():
new_rhs_typing_rel[typing_graph][p_rhs[p_node]] = set()
new_rhs_typing_rel[typing_graph][p_rhs[p_node]].add(
new_lhs_typing[typing_graph][l_node])
# Second step of autocompletion of rhs typing
for graph, typing in new_rhs_typing_rel.items():
ancestors = hierarchy.get_ancestors(graph)
for ancestor, ancestor_typing in ancestors.items():
dif = set(typing.keys()) -\
set(new_rhs_typing_rel[ancestor].keys())
for node in dif:
type_set = set()
for el in new_rhs_typing_rel[graph][node]:
type_set.add(ancestor_typing[el])
new_rhs_typing_rel[ancestor][node] = type_set
return (new_lhs_typing, new_rhs_typing_rel)
else:
return (None, None)
def added_edge_attrs(self):
"""."""
attrs = dict()
for s, t in self.rhs.edges():
s_p_nodes = keys_by_value(self.p_rhs, s)
t_p_nodes = keys_by_value(self.p_rhs, t)
new_attrs = {}
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) in self.p.edges():
new_attrs = attrs_union(
new_attrs,
dict_sub(
self.rhs.edge[s][t],
self.p.edge[s_p_node][t_p_node]
)
)
return attrs
def removed_edges(self):
"""Get edges removed by the rule.
Returns
-------
edges : set
Set of edges from `lhs` removed by the rule.
"""
edges = set()
for s, t in self.lhs.edges():
s_p_nodes = keys_by_value(self.p_lhs, s)
t_p_nodes = keys_by_value(self.p_lhs, t)
if len(s_p_nodes) != 0 and len(t_p_nodes) != 0:
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) not in self.p.edges():
edges.add((s_p_node, t_p_node))
return edges
def _add_node_attrs_lhs(self, n, attrs):
if n not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the lhs "
"of the rule" % n)
primitives.add_node_attrs(self.lhs, n, attrs)
p_nodes = keys_by_value(self.p_rhs, n)
for p_node in p_nodes:
primitives.add_node_attrs(self.p, p_node, attrs)
def get_unique_map(a, b, c, d, a_b, b_d, c_d):
"""Get a map a->c that makes a square commute."""
a_c = dict()
for node in b.nodes():
a_keys = keys_by_value(a_b, node)
if len(a_keys) > 0:
# node stayed in the rule
if node in b_d.keys():
d_node = b_d[node]
c_keys = keys_by_value(
c_d,
d_node
)
if len(a_keys) != len(c_keys):
raise ReGraphError("Map is not unique!")
else:
for i, a_key in enumerate(a_keys):
a_c[a_key] = c_keys[i]
return a_c
def get_unique_map_to_pullback(p, p_a, p_b, z_a, z_b):
"""Find a unique map to pullback."""
z_p = dict()
for value in p:
z_keys_from_a = set()
if value in p_a.keys():
a_value = p_a[value]
z_keys_from_a = set(keys_by_value(z_a, a_value))
z_keys_from_b = set()
if value in p_b.keys():
b_value = p_b[value]
z_keys_from_b.update(keys_by_value(z_b, b_value))
z_keys = z_keys_from_a.intersection(z_keys_from_b)
for z_key in z_keys:
z_p[z_key] = value
return z_p
def get_unique_map_to_pullback(p, p_a, p_b, z_a, z_b):
"""Find a unique map to pullback."""
z_p = dict()
for value in p:
z_keys_from_a = set()
if value in p_a.keys():
a_value = p_a[value]
z_keys_from_a = set(keys_by_value(z_a, a_value))
z_keys_from_b = set()
if value in p_b.keys():
b_value = p_b[value]
z_keys_from_b.update(keys_by_value(z_b, b_value))
z_keys = z_keys_from_a.intersection(z_keys_from_b)
for z_key in z_keys:
z_p[z_key] = value
return z_p
def removed_edge_attrs(self):
"""."""
attrs = dict()
for s, t in self.lhs.edges():
s_p_nodes = keys_by_value(self.p_lhs, s)
t_p_nodes = keys_by_value(self.p_lhs, t)
new_attrs = {}
for s_p_node in s_p_nodes:
for t_p_node in t_p_nodes:
if (s_p_node, t_p_node) in self.p.edges():
new_attrs = attrs_union(
new_attrs,
dict_sub(
self.lhs.edge[s][t],
self.p.edge[s_p_node][t_p_node]
)
)
if len(new_attrs) > 0:
attrs[(s, t)] = new_attrs
return attrs
def remove_node_attrs_rhs(self, n, attrs):
"""Remove attrs of a node in the rhs."""
if n not in self.rhs.nodes():
raise RuleError(
"Node '%s' does not exist in the right hand "
"side of the rule" % n)
p_keys = keys_by_value(self.p_rhs, n)
for p_node in p_keys:
primitives.remove_node_attrs(self.p, p_node, attrs)
primitives.remove_node_attrs(self.rhs, n, attrs)
def removed_node_attrs(self):
"""."""
attrs = dict()
for node in self.lhs.nodes():
p_nodes = keys_by_value(self.p_lhs, node)
new_attrs = {}
for p_node in p_nodes:
new_attrs = attrs_union(new_attrs, dict_sub(
self.lhs.node[node], self.p.node[p_node]))
if len(new_attrs) > 0:
attrs[node] = new_attrs
return attrs
def get_unique_map_from_pushout(p, a_p, b_p, a_z, b_z):
"""Find a unique map to pushout."""
p_z = dict()
for value in p:
z_values = set()
a_values = set(keys_by_value(a_p, value))
for a_value in a_values:
if a_value in a_z.keys():
z_values.add(a_z[a_value])
b_values = set(keys_by_value(b_p, value))
for b_value in b_values:
if b_value in b_z.keys():
z_values.add(b_z[b_value])
if len(z_values) > 0:
if len(z_values) > 1:
raise ReGraphError("Cannot construct a unique map!")
p_z[value] = z_values.pop()
return p_z
def clone_node(self, n, node_name=None):
"""Clone a node of the graph."""
p_new_nodes = []
rhs_new_nodes = []
p_keys = keys_by_value(self.p_lhs, n)
for k in p_keys:
p_new_node = primitives.clone_node(self.p, k)
p_new_nodes.append(p_new_node)
rhs_new_node = primitives.clone_node(self.rhs, self.p_rhs[k])
rhs_new_nodes.append(rhs_new_node)
# self.p_lhs[k] = n
self.p_lhs[p_new_node] = n
self.p_rhs[p_new_node] = rhs_new_node
return (p_new_nodes, rhs_new_nodes)
def add_node_attrs(self, n, attrs):
"""Add node attributes to a node in the graph."""
if n not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the left "
"hand side of the rule" % n)
p_keys = keys_by_value(self.p_lhs, n)
if len(p_keys) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, "
"cannot add attributes" % n)
for k in p_keys:
primitives.add_node_attrs(self.rhs, self.p_rhs[k], attrs)
return
def added_node_attrs(self):
"""."""
attrs = dict()
for node in self.rhs.nodes():
p_nodes = keys_by_value(self.p_rhs, node)
# if len(p_nodes) == 0:
# attrs[node] = self.rhs.node[node]
new_attrs = {}
for p_node in p_nodes:
new_attrs = attrs_union(new_attrs, dict_sub(
self.rhs.node[node], self.p.node[p_node]))
if len(new_attrs) > 0:
attrs[node] = new_attrs
return attrs
def add_edge(self, n1, n2, attrs=None):
"""Add an edge in the graph."""
# Find nodes in p mapping to n1 & n2
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
for k1 in p_keys_1:
if k1 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in the "
"preserved part of the rule" % k1
)
for k2 in p_keys_2:
if k2 not in self.p.nodes():
raise RuleError(
"Node with the id '%s' does not exist in the "
"preserved part of the rule" % k2
)
rhs_key_1 = self.p_rhs[k1]
rhs_key_2 = self.p_rhs[k2]
if self.rhs.is_directed():
if (rhs_key_1, rhs_key_2) in self.rhs.edges():
raise RuleError(
"Edge '%s->%s' already exists in the right "
"hand side of the rule" %
(rhs_key_1, rhs_key_2)
)
primitives.add_edge(self.rhs, rhs_key_1, rhs_key_2, attrs)
else:
if (rhs_key_1, rhs_key_2) in self.rhs.edges() or\
(rhs_key_2, rhs_key_1) in self.rhs.edges():
raise RuleError(
"Edge '%s->%s' already exists in the right "
"hand side of the rule" %
(rhs_key_1, rhs_key_2)
)
primitives.add_edge(self.rhs, rhs_key_1, rhs_key_2, attrs)
return
def update_node_attrs(self, n, attrs):
"""Update attributes of a node."""
if n not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the left hand "
"side of the rule" % n)
p_keys = keys_by_value(self.p_lhs, n)
if len(p_keys) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, "
"cannot update attributes" % n)
for k in p_keys:
self.p.node[k] = None
primitives.update_node_attrs(self.rhs, self.p_rhs[k], attrs)
return
def clone_rhs_node(self, node, new_name=None):
"""Clone an rhs node."""
if node not in self.rhs.nodes():
raise RuleError(
"Node '%s' is not a node of right hand side" %
node
)
p_keys = keys_by_value(self.p_rhs, node)
if len(p_keys) == 0:
primitives.clone_node(self.rhs, node, new_name)
elif len(p_keys) == 1:
primitives.clone_node(self.rhs, node, new_name)
new_p_node = primitives.clone_node(self.p, p_keys[0])
self.p_rhs[new_p_node] = new_name
self.p_lhs[new_p_node] = self.p_lhs[p_keys[0]]
else:
raise RuleError("Cannot clone node that is result of merge!")
def update_edge_attrs(self, n1, n2, attrs):
"""Update the attributes of an edge with a new set `attrs`."""
if n1 not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the left hand side of the rule" %
n1
)
if n2 not in self.lhs.nodes():
raise RuleError(
"Node '%s' does not exist in the left hand side of the rule" %
n2
)
normalize_attrs(attrs)
if self.lhs.is_directed():
if (n1, n2) not in self.lhs.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the left hand "
"side of the rule" % (n1, n2)
)
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
if len(p_keys_1) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, cannot update "
"attributes from the incident edge" %
n2
)
if len(p_keys_2) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, cannot update "
"attributes from the incident edge" %
n1
)
for k1 in p_keys_1:
for k2 in p_keys_2:
self.p.edge[k1][k2] = None
primitives.update_edge_attrs(
self.rhs,
self.p_rhs[k1],
self.p_rhs[k2],
attrs
)
else:
if (n1, n2) not in self.lhs.edges() and\
(n2, n1) not in self.lhs.edges():
raise RuleError(
"Edge '%s->%s' does not exist in the "
"left hand side of the rule" %
(n1, n2)
)
p_keys_1 = keys_by_value(self.p_lhs, n1)
p_keys_2 = keys_by_value(self.p_lhs, n2)
if len(p_keys_1) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, cannot update "
"attributes from the incident edge" %
n1
)
if len(p_keys_2) == 0:
raise RuleError(
"Node '%s' is being removed by the rule, cannot update "
"attributes from the incident edge" %
n2
)
for k1 in p_keys_1:
for k2 in p_keys_2:
self.p.edge[k1][k2] = None
primitives.update_edge_attrs(
self.rhs,
self.p_rhs[k1],
self.p_rhs[k2],
attrs
)
return
def _rewrite_base(hierarchy, graph_id, rule, instance,
lhs_typing, rhs_typing, inplace=False):
g_m, p_g_m, g_m_g =\
pullback_complement(rule.p, rule.lhs, hierarchy.node[graph_id].graph,
rule.p_lhs, instance, inplace)
g_prime, g_m_g_prime, r_g_prime = pushout(rule.p, g_m, rule.rhs,
p_g_m, rule.p_rhs, inplace)
relation_updates = []
for related_g in hierarchy.adjacent_relations(graph_id):
relation_updates.append((graph_id, related_g))
updated_homomorphisms = dict()
for typing_graph in hierarchy.successors(graph_id):
new_hom = copy.deepcopy(hierarchy.edge[graph_id][typing_graph].mapping)
removed_nodes = set()
new_nodes = dict()
for node in rule.lhs.nodes():
p_keys = keys_by_value(rule.p_lhs, node)
# nodes that were removed
if len(p_keys) == 0:
removed_nodes.add(instance[node])
elif len(p_keys) == 1:
if typing_graph not in rhs_typing.keys() or\
rule.p_rhs[p_keys[0]] not in rhs_typing[typing_graph].keys():
if r_g_prime[rule.p_rhs[p_keys[0]]] in new_hom.keys():
removed_nodes.add(r_g_prime[rule.p_rhs[p_keys[0]]])
# nodes were clonned
elif len(p_keys) > 1:
for k in p_keys:
if typing_graph in rhs_typing.keys() and\
rule.p_rhs[k] in rhs_typing[typing_graph].keys():
new_nodes[r_g_prime[rule.p_rhs[k]]] =\
list(rhs_typing[typing_graph][rule.p_rhs[k]])[0]
else:
removed_nodes.add(r_g_prime[rule.p_rhs[k]])
for node in rule.rhs.nodes():
p_keys = keys_by_value(rule.p_rhs, node)
# nodes that were added
if len(p_keys) == 0:
if typing_graph in rhs_typing.keys():
if node in rhs_typing[typing_graph].keys():
new_nodes[node] = list(rhs_typing[
typing_graph][node])[0]
# nodes that were merged
elif len(p_keys) > 1:
for k in p_keys:
removed_nodes.add(p_g_m[k])
# assign new type of node
if typing_graph in rhs_typing.keys():
if node in rhs_typing[typing_graph].keys():
new_type = list(rhs_typing[typing_graph][node])
new_nodes[r_g_prime[node]] = new_type
# update homomorphisms
for n in removed_nodes:
if n in new_hom.keys():
del new_hom[n]
new_hom.update(new_nodes)
updated_homomorphisms.update({
(graph_id, typing_graph): new_hom
})
return {
"graph": (g_m, p_g_m, g_m_g, g_prime, g_m_g_prime, r_g_prime),
"homomorphisms": updated_homomorphisms,
"relations": relation_updates
}
def _propagate_rule_to(graph, origin_typing, rule, instance, p_origin,
inplace=False):
if inplace is True:
graph_prime = graph
else:
graph_prime = copy.deepcopy(graph)
lhs_removed_nodes = rule.removed_nodes()
lhs_removed_node_attrs = rule.removed_node_attrs()
p_removed_edges = rule.removed_edges()
p_removed_edge_attrs = rule.removed_edge_attrs()
lhs_cloned_nodes = rule.cloned_nodes()
graph_prime_graph = id_of(graph.nodes())
graph_prime_origin = dict()
for lhs_node in rule.lhs.nodes():
origin_node = instance[lhs_node]
g_nodes = keys_by_value(
origin_typing, origin_node)
for node in g_nodes:
if lhs_node in lhs_removed_nodes:
primitives.remove_node(
graph_prime, node)
del graph_prime_graph[node]
else:
graph_prime_origin[node] = origin_node
for lhs_node, p_nodes in lhs_cloned_nodes.items():
nodes_to_clone = keys_by_value(origin_typing, instance[lhs_node])
for node in nodes_to_clone:
for i, p_node in enumerate(p_nodes):
if i == 0:
graph_prime_origin[node] = p_origin[p_node]
graph_prime_graph[node] = node
else:
new_name = primitives.clone_node(
graph_prime,
node)
graph_prime_origin[new_name] = p_origin[p_node]
graph_prime_graph[new_name] = node
for lhs_node, attrs in lhs_removed_node_attrs.items():
nodes_to_remove_attrs = keys_by_value(
origin_typing, instance[lhs_node])
for node in nodes_to_remove_attrs:
primitives.remove_node_attrs(
graph_prime,
node, attrs)
for p_u, p_v in p_removed_edges:
us = keys_by_value(graph_prime_origin, p_origin[p_u])
vs = keys_by_value(graph_prime_origin, p_origin[p_v])
for u in us:
for v in vs:
if (u, v) in graph_prime.edges():
primitives.remove_edge(
graph_prime, u, v)
for (p_u, p_v), attrs in p_removed_edge_attrs.items():
us = keys_by_value(origin_typing, p_origin[p_u])
vs = keys_by_value(origin_typing, p_origin[p_v])
for u in us:
for v in vs:
primitives.removed_edge_attrs(
graph_prime, u, v, attrs)
return (graph_prime, graph_prime_graph, graph_prime_origin)