## Creature Project
## CSC323
## 4/17/10
## rule.py: Contains methods associated with the class Rule.

#Add Import Statement Here

class Rule():
    """Holds a predicate and a list of actions to execute if
       the predicate holds true"""
    def __init__(self, pred, instructions):
        self.predicate = pred
        self.instructions = instructions
              
    def holds(self, world, coordinates):
        """If the predicate resolves as true, returns true,
           otherwise returns false."""
        if self.predicate.holds(world, coordinates):
            return True
        else:
            return False

    def getInstructions(self, coordinates):
        """Returns a list of packed instruction objects.
        These are all the instructions that are to used if the rule's predicate
        holds."""
        packedInstructions = []
        for i in self.instructions:
            packedInstructions.append(i.pack(coordinates))
        return packedInstructions

    def __str__(self):
        """Overwrites the to string method for a rule."""
        ruleString = "Predicate: " + str(self.predicate)+ "\n Instructions: { "  
        for i in self.instructions:
            ruleString += str(i) + " "
        ruleString += "}"
        return ruleString
    
    def save_the_rule(self):
        """A method for saving rules"""
        ruleString = "R{P" + str(self.predicate)
        for i in self.instructions:
            ruleString += "\n" + i.save_the_instruction()
        ruleString += "}"
        return ruleString