def __enable_disjunction_for_nodes__(SOA, nodes):
"""
Enables the Disjunction Rewrite Rule for `nodes`.
NOTE: This may introduce self-loops, so applying `rewrite` MAY
choose the SELF-LOOP instead which effectively fools this. Thus
we apply `__disjunctionrule__` at the end of the rule.
"""
def is_valid(nodes):
pred = SOA.pred(nodes[0])
succ = SOA.succ(nodes[0])
for which in nodes[1:]:
pred &= SOA.pred(which)
succ &= SOA.succ(which)
return pred == SOA.pred(nodes[0]) and succ == SOA.succ(nodes[0])
valid = is_valid(nodes)
while not valid:
pred = set()
succ = set()
for which in nodes:
pred |= SOA.pred(which)
succ |= SOA.succ(which)
for which in nodes:
for source in (x for x in pred if x not in SOA.pred(which)):
SOA.addedge((source, which))
for target in (x for x in succ if x not in SOA.succ(which)):
SOA.addedge((which, target))
valid = is_valid(nodes)
assert __disjunctionrule__(SOA)
def testNonApplicableDisjunction(self):
self.assertEqual(__disjunctionrule__(self.tree), False)
self.assertEqual(len(self.tree), 7)
def testConjunctionRuleApplied(self):
__optionalrule__(self.graph)
__disjunctionrule__(self.graph)
self.assertEqual(__concatrule__(self.graph), True)
self.assert_(Conjunction([Optional('b'), Disjunction(['c', 'a'])]) in self.graph.nodes)
def testDisjunctionRuleApplied(self):
__optionalrule__(self.graph)
self.assertEqual(__disjunctionrule__(self.graph), True)
self.assert_(Disjunction(('a', 'c')) in self.graph.nodes)