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yap-6.3/packages/python/yapex.py
Vitor Santos Costa b2156aad2d python swig work
2016-09-21 14:55:09 -05:00

85 lines
2.1 KiB
Python

import yap
import sys
# 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
engine.close()
#
# initialize engine
# engine = yap.YAPEngine();
# engine = yap.YAPEngine(yap.YAPParams());
live()