def __init__(self, subj, pred, t='now', truth=1):
self.truth = truth
if isinstance(pred, str):
self.predicate = Exists(pred)
else:
if not isinstance(pred, Exists) and \
not isinstance(pred, ClassVarVar):
raise ValueError('The predicate of a fact has to be a verb')
self.predicate = pred
if isinstance(subj, str):
if utils.varpat.match(subj):
self.subject = self.pred.subject(subj)
else:
from nl import kb
try:
self.subject = kb.ask_obj(Thing(subj))[0]
except IndexError:
self.subject = utils.get_class(subj)
if not self.subject:
raise ValueError('If Fact receives a string as subject'
'It has to be a variable or a thing'
'already defined in the knowledge base')
else:
if not isinstance(subj, Thing) and \
not isinstance(subj, Word) and \
not isinstance(subj, ClassVar) and \
not isinstance(subj, ClassVarVar):
raise ValueError('Not a proper subject for fact')
self.subject = subj
subj = self.subject
if not isinstance(subj, ClassVar) and \
not isinstance(subj, ClassVarVar) and \
(not isinstance(self.predicate, ClassVar) and
not isinstance(self.predicate, ClassVarVar) and
not isinstance(subj, self.predicate.subject)):
raise ValueError('Not a proper subject for %s' %
self.predicate.__class__.__name__)
if isinstance(t, Namable):
self.time = t
else:
self.time = Instant(t)
class Fact(Namable):
"""
A fact is built with a subj and a pred positional arguments.
subj is either an object of Thing or any of its subclasses,
or a class chosen among Thing, Exists, or any subclass of them.
It can also take a named argument, often given as a 3rd
positional arg, that has to be of type Time,
and a named arg 'truth', that is either 0 or 1.
"""
def __init__(self, subj, pred, t=Instant('now'), truth=1):
self.truth = truth
if isinstance(pred, str):
self.predicate = Exists(pred)
else:
if not isinstance(pred, Exists) and \
not isinstance(pred, ClassVarVar):
raise ValueError('The predicate of a fact has to be a verb')
self.predicate = pred
if isinstance(subj, str):
if utils.varpat.match(subj):
self.subject = self.pred.subject(subj)
else:
from nl import kb
self.subject = kb.ask_obj(Thing(subj))[0]
if not self.subject:
raise ValueError('If Fact receives a string as subject'
'It has to be a variable or a thing'
'already defined in the knowledge base')
else:
if not isinstance(subj, Thing) and \
not isinstance(subj, Word) and \
not isinstance(subj, ClassVar) and \
not isinstance(subj, ClassVarVar):
raise ValueError('Not a proper subject for fact')
self.subject = subj
if not isinstance(subj, ClassVar) and \
not isinstance(subj, ClassVarVar) and \
(not isinstance(self.predicate, ClassVar) and
not isinstance(self.predicate, ClassVarVar) and
not isinstance(subj, self.predicate.subject)):
raise ValueError('Not a proper subject for %s' %
self.predicate.__class__.__name__)
if isinstance(t, Namable):
self.time = t
else:
self.time = Instant(t)
def __str__(self):
negation = not self.truth and ' not' or ''
return '%s%s %s at %s' % (str(self.subject),
negation,
str(self.predicate),
str(self.time))
@classmethod
def from_clips(cls, instance):
if not isinstance(instance, clips._clips_wrap.Instance):
instance = clips.FindInstance(instance)
s = instance.GetSlot('subject')
if isinstance(instance, clips._clips_wrap.Class):
s = Word.from_clips(s)
else:
s = Namable.from_clips(s)
p = Exists.from_clips(instance.GetSlot('predicate'))
t = Time.from_clips(instance.GetSlot('time'))
truth = instance.GetSlot('truth')
return Fact(s, p, t, truth=truth)
def negate(self):
self.truth = not self.truth and 1 or 0
negated = str(self)
self.truth = not self.truth and 1 or 0
return negated
def get_ism(self, templs, queries, vrs, newvar='fact'):
"""
get instance-set method;
return (instance-set templates, instance-set queries)
"""
templs.append((newvar, self.__class__.__name__))
isc_meth = getattr(self.subject, 'get_isc_cls', self.subject.get_isc)
isc_meth(queries, vrs, newvar, ('subject',))
self.predicate.get_isc(queries, vrs, newvar, ('predicate',))
self.time.get_isc(queries, vrs, newvar, ('time',))
queries.append('(eq ?%s:truth %s)' % (newvar,
self.truth))
return newvar
def get_ce(self, vrs=None):
"""
put proposition in clips as a conditional element of a rule
"""
if vrs is None: vrs = []
ce = '(logical (object (is-a Fact) (subject %s) (predicate %s) (time %s) (truth %s)))'
constraint_meth = getattr(self.subject, 'clsput', self.subject.get_slot_constraint)
s = constraint_meth(vrs)
constraint_meth = getattr(self.predicate, 'clsput', self.predicate.get_slot_constraint)
p = constraint_meth(vrs)
return ce % (s, p,
self.time.get_slot_constraint(vrs),
self.truth)
def put_action(self, vrs=None):
"""
put proposition in clips as an action that makes the proposition
"""
if vrs is None:
vrs = {}
put_meth = getattr(self.subject, 'clsput', self.subject.put)
s = put_meth(vrs)
put_meth = getattr(self.predicate, 'clsput', self.predicate.put)
p = put_meth(vrs)
t = self.time.put(vrs)
return '(add-prop %s %s %s %s)' % (s, p, t, self.truth)