def parse(str_rule):
# Example: daughter(Person, Parent) :- female(Person), parent(Parent, Person).
str_rule = str_rule.strip().rstrip('.').replace(' ', '')
idx = str_rule.find(':-')
conclusion = Fact.parse(str_rule[:idx])
premises = []
list_fact = str_rule[idx + 2:].split('),')
for idx, str_fact in enumerate(list_fact):
if idx != len(list_fact) - 1:
str_fact += ')'
fact = Fact.parse(str_fact)
premises.append(fact)
return Rule(conclusion, premises)
def process(file, isInput = False):
global knowledgeBase, infertype
cmds = []
while True:
if isInput:
sys.stdout.write('? ' if len(cmds) == 0 else '| ')
sys.stdout.flush()
line = file.readline()
if line == "": break
s = re.sub("#.*", "", line[:-1]) # ignore comments
s = re.sub(" ", "", s) # remove white spaces
if s == "": continue
if s[-1] == '.':
s=s[:-1]
cmds.append(s)
# if punc == '.': print(s)
for cmd in cmds:
if cmd == "": continue
if cmd == 'printKB':
print(knowledgeBase)
elif cmd == 'halt': sys.exit(0)
else:
if isInput:
if (infertype == Inferring.FORWARD.value):
print(fol_fc_ask(knowledgeBase, Fact.parse(cmd)))
elif (infertype == Inferring.BACKWARD.value):
bc = BackwardChaining(knowledgeBase, Fact.parse(cmd))
print(bc.answer())
elif (infertype == Inferring.RESOLUTION.value):
print(resolution_search(knowledgeBase, Fact.parse(cmd)))
else:
if (cmd.find(":-") == -1):
knowledgeBase.appendFact(Fact.parse(s))
else:
knowledgeBase.appendRule(Rule.parse(s))
cmds = []
else: cmds.append(s)
if not isInput:
file.close()
