Flora2KB.py

# -*- coding: utf-8 -*-
from logic import KB
from pyxf import flora2


class Flora2KB(KB):
    '''Flora2 knowledge base'''
    def __init__(self, sentence=None, path='runflora'):
        '''Constructor method
        Usage: Flora2KB( sentence, path )
        sentence - F-logic sentence to be added to the KB (default: None)
        path - path to Flora2 executable (default: 'runflora')'''
        self.flora2 = flora2(path)
        if sentence:
            self.tell(sentence)

    def tell(self, sentence, type='insert'):
        '''Adds sentence to KB
        Usage: instance.tell( sentence, type )
        sentence - frame logic sentence to be added to KB
        type - insertion type (one of insert, insertall, t_insert, t_insertall, insertrule, newmodule; default: 'insert')'''
        sentence = sentence.strip()
        if sentence[-1] == '.':
            sentence = sentence[:-1]
        return self.flora2.query(type + '{' + sentence + '}')

    def ask(self, query):
        '''Queries the KB'''
        return self.flora2.query(query)

    def retract(self, sentence, type='delete'):
        '''Deletes sentence from KB
        Usage: instance.retract( sentence, type )
        sentence - frame logic sentence to be deleted from KB
        type - deletion type (one of delete, deleteall, erase, eraseall, t_delete, t_deleteall, t_erase, t_eraseall, deletetrule, erasemodule; default: 'delete')'''
        sentence = sentence.strip()
        if sentence[-1] == '.':
            sentence = sentence[:-1]
        return self.flora2.query(type + '{' + sentence + '}')

    def loadModule(self, module):
        '''Loads module to KB
        Usage: instance.loadModule( path )
        path - path to module'''
        self.flora2.load(module)

if __name__ == '__main__':
    kb = Flora2KB()
    kb.tell('a[ b->c ]')
    kb.tell('( ?x[ c->?y ] :- ?x[ b->?y ] )', 'insertrule')
    for result in kb.ask('?x[ ?y->?z ]'):
        print( result )
    kb.retract('a[ b->c ]')