diff options
Diffstat (limited to 'aiml/PatternMgr.py')
| -rw-r--r-- | aiml/PatternMgr.py | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/aiml/PatternMgr.py b/aiml/PatternMgr.py new file mode 100644 index 0000000..21b73f1 --- /dev/null +++ b/aiml/PatternMgr.py @@ -0,0 +1,329 @@ +# This class implements the AIML pattern-matching algorithm described +# by Dr. Richard Wallace at the following site: +# http://www.alicebot.org/documentation/matching.html + +import marshal +import pprint +import re +import string +import sys + +class PatternMgr: + # special dictionary keys + _UNDERSCORE = 0 + _STAR = 1 + _TEMPLATE = 2 + _THAT = 3 + _TOPIC = 4 + _BOT_NAME = 5 + + def __init__(self): + self._root = {} + self._templateCount = 0 + self._botName = u"Nameless" + punctuation = "\"`~!@#$%^&*()-_=+[{]}\|;:',<.>/?" + self._puncStripRE = re.compile("[" + re.escape(punctuation) + "]") + self._whitespaceRE = re.compile("\s", re.LOCALE | re.UNICODE) + + def numTemplates(self): + """Return the number of templates currently stored.""" + return self._templateCount + + def setBotName(self, name): + """Set the name of the bot, used to match <bot name="name"> tags in + patterns. The name must be a single word! + + """ + # Collapse a multi-word name into a single word + self._botName = unicode(string.join(name.split())) + + def dump(self): + """Print all learned patterns, for debugging purposes.""" + pprint.pprint(self._root) + + def save(self, filename): + """Dump the current patterns to the file specified by filename. To + restore later, use restore(). + + """ + try: + outFile = open(filename, "wb") + marshal.dump(self._templateCount, outFile) + marshal.dump(self._botName, outFile) + marshal.dump(self._root, outFile) + outFile.close() + except Exception, e: + print "Error saving PatternMgr to file %s:" % filename + raise Exception, e + + def restore(self, filename): + """Restore a previously save()d collection of patterns.""" + try: + inFile = open(filename, "rb") + self._templateCount = marshal.load(inFile) + self._botName = marshal.load(inFile) + self._root = marshal.load(inFile) + inFile.close() + except Exception, e: + print "Error restoring PatternMgr from file %s:" % filename + raise Exception, e + + def add(self, (pattern,that,topic), template): + """Add a [pattern/that/topic] tuple and its corresponding template + to the node tree. + + """ + # TODO: make sure words contains only legal characters + # (alphanumerics,*,_) + + # Navigate through the node tree to the template's location, adding + # nodes if necessary. + node = self._root + for word in string.split(pattern): + key = word + if key == u"_": + key = self._UNDERSCORE + elif key == u"*": + key = self._STAR + elif key == u"BOT_NAME": + key = self._BOT_NAME + if not node.has_key(key): + node[key] = {} + node = node[key] + + # navigate further down, if a non-empty "that" pattern was included + if len(that) > 0: + if not node.has_key(self._THAT): + node[self._THAT] = {} + node = node[self._THAT] + for word in string.split(that): + key = word + if key == u"_": + key = self._UNDERSCORE + elif key == u"*": + key = self._STAR + if not node.has_key(key): + node[key] = {} + node = node[key] + + # navigate yet further down, if a non-empty "topic" string was included + if len(topic) > 0: + if not node.has_key(self._TOPIC): + node[self._TOPIC] = {} + node = node[self._TOPIC] + for word in string.split(topic): + key = word + if key == u"_": + key = self._UNDERSCORE + elif key == u"*": + key = self._STAR + if not node.has_key(key): + node[key] = {} + node = node[key] + + + # add the template. + if not node.has_key(self._TEMPLATE): + self._templateCount += 1 + node[self._TEMPLATE] = template + + def match(self, pattern, that, topic): + """Return the template which is the closest match to pattern. The + 'that' parameter contains the bot's previous response. The 'topic' + parameter contains the current topic of conversation. + + Returns None if no template is found. + + """ + if len(pattern) == 0: + return None + # Mutilate the input. Remove all punctuation and convert the + # text to all caps. + input = string.upper(pattern) + input = re.sub(self._puncStripRE, "", input) + if that.strip() == u"": that = u"ULTRABOGUSDUMMYTHAT" # 'that' must never be empty + thatInput = string.upper(that) + thatInput = re.sub(self._whitespaceRE, " ", thatInput) + thatInput = re.sub(self._puncStripRE, "", thatInput) + if topic.strip() == u"": topic = u"ULTRABOGUSDUMMYTOPIC" # 'topic' must never be empty + topicInput = string.upper(topic) + topicInput = re.sub(self._puncStripRE, "", topicInput) + + # Pass the input off to the recursive call + patMatch, template = self._match(input.split(), thatInput.split(), topicInput.split(), self._root) + return template + + def star(self, starType, pattern, that, topic, index): + """Returns a string, the portion of pattern that was matched by a *. + + The 'starType' parameter specifies which type of star to find. + Legal values are: + - 'star': matches a star in the main pattern. + - 'thatstar': matches a star in the that pattern. + - 'topicstar': matches a star in the topic pattern. + + """ + # Mutilate the input. Remove all punctuation and convert the + # text to all caps. + input = string.upper(pattern) + input = re.sub(self._puncStripRE, "", input) + if that.strip() == u"": that = u"ULTRABOGUSDUMMYTHAT" # 'that' must never be empty + thatInput = string.upper(that) + thatInput = re.sub(self._whitespaceRE, " ", thatInput) + thatInput = re.sub(self._puncStripRE, "", thatInput) + if topic.strip() == u"": topic = u"ULTRABOGUSDUMMYTOPIC" # 'topic' must never be empty + topicInput = string.upper(topic) + topicInput = re.sub(self._puncStripRE, "", topicInput) + + # Pass the input off to the recursive pattern-matcher + patMatch, template = self._match(input.split(), thatInput.split(), topicInput.split(), self._root) + if template == None: + return "" + + # Extract the appropriate portion of the pattern, based on the + # starType argument. + words = None + if starType == 'star': + patMatch = patMatch[:patMatch.index(self._THAT)] + words = input.split() + elif starType == 'thatstar': + patMatch = patMatch[patMatch.index(self._THAT)+1 : patMatch.index(self._TOPIC)] + words = thatInput.split() + elif starType == 'topicstar': + patMatch = patMatch[patMatch.index(self._TOPIC)+1 :] + words = topicInput.split() + else: + # unknown value + raise ValueError, "starType must be in ['star', 'thatstar', 'topicstar']" + + # compare the input string to the matched pattern, word by word. + # At the end of this loop, if foundTheRightStar is true, start and + # end will contain the start and end indices (in "words") of + # the substring that the desired star matched. + foundTheRightStar = False + start = end = j = numStars = k = 0 + for i in range(len(words)): + # This condition is true after processing a star + # that ISN'T the one we're looking for. + if i < k: + continue + # If we're reached the end of the pattern, we're done. + if j == len(patMatch): + break + if not foundTheRightStar: + if patMatch[j] in [self._STAR, self._UNDERSCORE]: #we got a star + numStars += 1 + if numStars == index: + # This is the star we care about. + foundTheRightStar = True + start = i + # Iterate through the rest of the string. + for k in range (i, len(words)): + # If the star is at the end of the pattern, + # we know exactly where it ends. + if j+1 == len (patMatch): + end = len (words) + break + # If the words have started matching the + # pattern again, the star has ended. + if patMatch[j+1] == words[k]: + end = k - 1 + i = k + break + # If we just finished processing the star we cared + # about, we exit the loop early. + if foundTheRightStar: + break + # Move to the next element of the pattern. + j += 1 + + # extract the star words from the original, unmutilated input. + if foundTheRightStar: + #print string.join(pattern.split()[start:end+1]) + if starType == 'star': return string.join(pattern.split()[start:end+1]) + elif starType == 'thatstar': return string.join(that.split()[start:end+1]) + elif starType == 'topicstar': return string.join(topic.split()[start:end+1]) + else: return "" + + def _match(self, words, thatWords, topicWords, root): + """Return a tuple (pat, tem) where pat is a list of nodes, starting + at the root and leading to the matching pattern, and tem is the + matched template. + + """ + # base-case: if the word list is empty, return the current node's + # template. + if len(words) == 0: + # we're out of words. + pattern = [] + template = None + if len(thatWords) > 0: + # If thatWords isn't empty, recursively + # pattern-match on the _THAT node with thatWords as words. + try: + pattern, template = self._match(thatWords, [], topicWords, root[self._THAT]) + if pattern != None: + pattern = [self._THAT] + pattern + except KeyError: + pattern = [] + template = None + elif len(topicWords) > 0: + # If thatWords is empty and topicWords isn't, recursively pattern + # on the _TOPIC node with topicWords as words. + try: + pattern, template = self._match(topicWords, [], [], root[self._TOPIC]) + if pattern != None: + pattern = [self._TOPIC] + pattern + except KeyError: + pattern = [] + template = None + if template == None: + # we're totally out of input. Grab the template at this node. + pattern = [] + try: template = root[self._TEMPLATE] + except KeyError: template = None + return (pattern, template) + + first = words[0] + suffix = words[1:] + + # Check underscore. + # Note: this is causing problems in the standard AIML set, and is + # currently disabled. + if root.has_key(self._UNDERSCORE): + # Must include the case where suf is [] in order to handle the case + # where a * or _ is at the end of the pattern. + for j in range(len(suffix)+1): + suf = suffix[j:] + pattern, template = self._match(suf, thatWords, topicWords, root[self._UNDERSCORE]) + if template is not None: + newPattern = [self._UNDERSCORE] + pattern + return (newPattern, template) + + # Check first + if root.has_key(first): + pattern, template = self._match(suffix, thatWords, topicWords, root[first]) + if template is not None: + newPattern = [first] + pattern + return (newPattern, template) + + # check bot name + if root.has_key(self._BOT_NAME) and first == self._botName: + pattern, template = self._match(suffix, thatWords, topicWords, root[self._BOT_NAME]) + if template is not None: + newPattern = [first] + pattern + return (newPattern, template) + + # check star + if root.has_key(self._STAR): + # Must include the case where suf is [] in order to handle the case + # where a * or _ is at the end of the pattern. + for j in range(len(suffix)+1): + suf = suffix[j:] + pattern, template = self._match(suf, thatWords, topicWords, root[self._STAR]) + if template is not None: + newPattern = [self._STAR] + pattern + return (newPattern, template) + + # No matches were found. + return (None, None)
\ No newline at end of file |