#!/usr/bin/env python2
# -*- coding: utf-8 -*-
# This code is PEP8-compliant. See http://www.python.org/dev/peps/pep-0008.
from __future__ import unicode_literals
import re
from alex.utils.config import load_as_module
from alex.utils.cache import lru_cache
[docs]class OntologyException(Exception):
pass
[docs]class Ontology(object):
"""Represents an ontology for a dialogue domain.
"""
def __init__(self, file_name=None):
self.ontology = {}
if file_name:
self.load(file_name)
def __getitem__(self, key):
return self.ontology[key]
def __contains__(self, key):
return key in self.ontology
[docs] def load(self, file_name):
on_mod = load_as_module(file_name, force=True)
if not hasattr(on_mod, 'ontology'):
raise OntologyException("The ontology file does not define the 'ontology' object!")
self.ontology = on_mod.ontology
[docs] def slot_has_value(self, name, value):
""" Check whether the slot and the value are compatible.
"""
return value in self.ontology['slots'][name]
[docs] def slot_is_binary(self, name):
"""Check whether the given slot has a binary value (using the 'binary' key in the 'slot_attributes' for the
given slot name).
:param name: name of the slot being checked
"""
return 'binary' in self.ontology['slot_attributes'][name]
@lru_cache(maxsize=10)
[docs] def slots_system_requests(self):
""" Return all slots the system can request.
"""
return [slot for slot in self.ontology['slots'] if 'system_requests' in self.ontology['slot_attributes'][slot]]
@lru_cache(maxsize=10)
[docs] def slots_system_confirms(self):
""" Return all slots the system can request.
"""
return [slot for slot in self.ontology['slots'] if 'system_confirms' in self.ontology['slot_attributes'][slot]]
@lru_cache(maxsize=10)
[docs] def slots_system_selects(self):
""" Return all slots the system can request.
"""
return [slot for slot in self.ontology['slots'] if 'system_selects' in self.ontology['slot_attributes'][slot]]
@lru_cache(maxsize=1000)
[docs] def last_talked_about(self, da_type, name, value):
"""Returns a list of slots and values that should be used to for tracking about what was talked about recently,
given the input dialogue acts.
:param da_type: the source dialogue act type
:param name: the source slot name
:param value: the source slot value
:return: returns a list of target slot names and values used for tracking
"""
lta_tsv = []
da_type = da_type if da_type else ''
name = name if name else ''
value = value if value else ''
for target_slot, target_values in self.ontology['last_talked_about'].iteritems():
for target_value, source_patterns in target_values.iteritems():
for source_dat, source_name, source_value in source_patterns:
if re.match(source_dat, da_type) and re.match(source_name, name) and re.match(source_value, value):
lta_tsv.append((target_slot, target_value))
return lta_tsv
@lru_cache(maxsize=1000)
[docs] def reset_on_change(self, slot, changed_slot):
if slot in self.ontology['reset_on_change']:
for pattern in self.ontology['reset_on_change'][slot]:
if re.match(pattern, changed_slot):
return True
else:
return False
[docs] def get_compatible_vals(self, slot_pair, value):
"""Given a slot pair (key to 'compatible_values' in ontology data), this returns the set of compatible values
for the given key. If there is no information about the given pair, None is returned.
:param slot_pair: key to 'compatible_values' in ontology data
:param value: the subkey to check compatible values for
:rtype: set
"""
if slot_pair in self.ontology['compatible_values']:
return self.ontology['compatible_values'][slot_pair].get(value, set()).copy()
return None
[docs] def is_compatible(self, slot_pair, val1, val2):
"""Given a slot pair and a pair of values, this tests whether the values are compatible. If there is no
information about the slot pair or the first value, returns False. If the second value is None, returns
always True (i.e. None is compatible with anything).
:param slot_pair: key to 'compatible_values' in ontology data
:param val1: value of the 1st slot
:param val2: value of the 2nd slot
:rtype: Boolean
"""
if slot_pair in self.ontology['compatible_values']:
return val2 is None or val2 in self.ontology['compatible_values'][slot_pair].get(val1, set())
return False
[docs] def get_default_value(self, slot):
"""Given a slot name, get its default value (if set in the ontology). Returns None
if the default value is not set for the given slot.
:param slot: the name of the desired slot
:rtype: unicode
"""
if slot in self.ontology['default_values']:
return self.ontology['default_values'][slot]
return None