yap-6.3/packages/pyswip/examples/hanoi/hanoi.py

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

from collections import deque
from pyswip.prolog import Prolog
from pyswip.easy import getList, registerForeign

class Notifier:
    def __init__(self, fun):
        # type: (object) -> object
        self.fun = fun
        
    def notify(self, t):
        #return not self.fun(getList(t))
        return not self.fun(t)
    notify.arity = 1
    
class Tower:
    def __init__(self, N=3, interactive=False):
        # type: (object, object) -> object
        """N is the number of disks
        """
        self.N = N
        self.disks = dict(left=deque(range(N, 0, -1)), center=deque(), right=deque())
        self.started = False
        self.interactive = interactive
        self.step = 0
        
    def move(self, r):
        if not self.started:
            self.step += 1
            self.draw()
            self.started = True
        disks = self.disks
        disks[str(r[1])].append(disks[str(r[0])].pop())
        self.step += 1
        return self.draw()
        
    def draw(self):
        disks = self.disks
        print "\n Step", self.step
        for i in range(self.N):
            n = self.N - i - 1
            print " ",
            for pole in ["left", "center", "right"]:
                if len(disks[pole]) - n > 0:
                    print disks[pole][n],
                else:
                    print " ",
            print
        print "-"*9
        print " ", "L", "C", "R"        
        if self.interactive:
            cont = raw_input("Press 'n' to finish: ")
            return cont.lower() == "n"
                    

def main():
    N = 3
    INTERACTIVITY = True
    
    prolog = Prolog()
    tower = Tower(N, INTERACTIVITY)
    notifier = Notifier(tower.move)
    registerForeign(notifier.notify)
    prolog.consult("hanoi.pl")
    list(prolog.query("hanoi(%d)" % N))
    
if __name__ == "__main__":
    main()