import yap # this class is not being used # we rely on namedtuples instead. class T(tuple): """Represents a non-interned Prolog atom""" def __new__(self, s, tple): self.tuple.__new__(self, tple) self.name = s def __repr__(self): return "yapex.T(" + self.name + " , " + tuple.__repr__(self) + ")" def __str__(self): return str(self.name) + str(self.tuple) def query_prolog(engine, s): q = engine.query(s) ask = True while q.next(): vs = q.namedVarsCopy() if vs: i = 0 for eq in vs: name = eq[0] bind = eq[1] if bind.isVar(): var = yap.YAPAtom('$VAR') f = yap.YAPFunctor(var, 1) bind.unify(yap.YAPApplTerm(f, (name))) else: i = bind.numberVars(i, True) print(name.text() + " = " + bind.text()) print("yes") if q.deterministic(): q.close() return if ask: s = input("more(;/y), all(!/a), no ?").lstrip() if s.startswith(';') or s.startswith('y'): continue elif s.startswith('#'): exec(s.lstrip('#')) elif s.startswith('a'): ask = False else: break print("No (more) answers") q.close() return def live(): engine = yap.YAPEngine() loop = True while loop: try: s = input("?- ") if not s: loop = False query_prolog(engine, s) except SyntaxError as err: print("Syntax Error error: {0}".format(err)) except EOFError: return except RuntimeError as err: print("YAP Execution Error: {0}".format(err)) except ValueError: print("Could not convert data to an integer.") except: print("Unexpected error:", sys.exc_info()[0]) raise # # initialize engine # engine = yap.YAPEngine(); # engine = yap.YAPEngine(yap.YAPParams());