def compute_blocks(self):
"""
Compute the set of blocks that C infer
return: Topologically sorted blocks T_c
"""
timer_start('Compute blocks')
T_c = list()
T_unions = set()
# iterate the combination sizes in reverse
a = range(len(self.C)+1)[::-1]
for i in a:
choose = i
for comb in combinations(self.C, choose):
union = itemsets.union_of_itemsets(comb)
if not union in T_unions:
T_unions.add(union)
T = Block()
T.union_of_itemsets = union
T.singletons = itemsets.singletons_of_itemsets(comb)
T.itemsets = set(comb)
T_c.append(T)
timer_stop('Compute blocks')
return T_c
