# -*- coding: utf-8 -*-

# pyswip -- Python SWI-Prolog bridge
# Copyright (c) 2007-2018 Yüce Tekol
#  
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#  
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#  
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# Demonstrates registering a Python function as a Prolog predicate through SWI-Prolog's FFI.

from __future__ import print_function
from pyswip.prolog import Prolog
from pyswip.easy import registerForeign, getAtomChars


def hello(t):
    print("Hello,", t)
hello.arity = 1


def main():
    registerForeign(hello)
    prolog = Prolog()
    prolog.assertz("father(michael,john)")
    prolog.assertz("father(michael,gina)")    
    list(prolog.query("father(michael,X), hello(X)"))

    
if __name__ =="__main__":
    main()
