# Natural Language Toolkit: Interface to Boxer # # # Author: Dan Garrette # # Copyright (C) 2001-2013 NLTK Project # URL: # For license information, see LICENSE.TXT """ An interface to Boxer. This interface relies on the latest version of the development (subversion) version of C&C and Boxer. Usage: Set the environment variable CANDCHOME to the bin directory of your CandC installation. The models directory should be in the CandC root directory. For example: /path/to/candc/ bin/ candc boxer models/ boxer/ """ from __future__ import print_function, unicode_literals import os import re import operator import subprocess from optparse import OptionParser import tempfile from functools import reduce from nltk.internals import Counter, find_binary from nltk.sem.logic import (ExpectedMoreTokensException, ParseException, UnexpectedTokenException, Variable) from nltk.sem.drt import (DRS, DrtApplicationExpression, DrtEqualityExpression, DrtNegatedExpression, DrtOrExpression, DrtParser, DrtProposition, DrtTokens, DrtVariableExpression) from nltk.compat import python_2_unicode_compatible class Boxer(object): """ This class is an interface to Johan Bos's program Boxer, a wide-coverage semantic parser that produces Discourse Representation Structures (DRSs). """ def __init__(self, boxer_drs_interpreter=None, elimeq=False, bin_dir=None, verbose=False): """ :param boxer_drs_interpreter: A class that converts from the ``AbstractBoxerDrs`` object hierarchy to a different object. The default is ``NltkDrtBoxerDrsInterpreter``, which converts to the NLTK DRT hierarchy. :param elimeq: When set to true, Boxer removes all equalities from the DRSs and discourse referents standing in the equality relation are unified, but only if this can be done in a meaning-preserving manner. """ if boxer_drs_interpreter is None: boxer_drs_interpreter = NltkDrtBoxerDrsInterpreter() self._boxer_drs_interpreter = boxer_drs_interpreter self._elimeq = elimeq self.set_bin_dir(bin_dir, verbose) def set_bin_dir(self, bin_dir, verbose=False): self._candc_bin = self._find_binary('candc', bin_dir, verbose) self._candc_models_path = os.path.normpath(os.path.join(self._candc_bin[:-5], '../models')) self._boxer_bin = self._find_binary('boxer', bin_dir, verbose) def interpret(self, input, discourse_id=None, question=False, verbose=False): """ Use Boxer to give a first order representation. :param input: str Input sentence to parse :param occur_index: bool Should predicates be occurrence indexed? :param discourse_id: str An identifier to be inserted to each occurrence-indexed predicate. :return: ``drt.AbstractDrs`` """ discourse_ids = ([discourse_id] if discourse_id is not None else None) d, = self.batch_interpret_multisentence([[input]], discourse_ids, question, verbose) if not d: raise Exception('Unable to interpret: "%s"' % input) return d def interpret_multisentence(self, input, discourse_id=None, question=False, verbose=False): """ Use Boxer to give a first order representation. :param input: list of str Input sentences to parse as a single discourse :param occur_index: bool Should predicates be occurrence indexed? :param discourse_id: str An identifier to be inserted to each occurrence-indexed predicate. :return: ``drt.AbstractDrs`` """ discourse_ids = ([discourse_id] if discourse_id is not None else None) d, = self.batch_interpret_multisentence([input], discourse_ids, question, verbose) if not d: raise Exception('Unable to interpret: "%s"' % input) return d def batch_interpret(self, inputs, discourse_ids=None, question=False, verbose=False): """ Use Boxer to give a first order representation. :param inputs: list of str Input sentences to parse as individual discourses :param occur_index: bool Should predicates be occurrence indexed? :param discourse_ids: list of str Identifiers to be inserted to each occurrence-indexed predicate. :return: list of ``drt.AbstractDrs`` """ return self.batch_interpret_multisentence([[input] for input in inputs], discourse_ids, question, verbose) def batch_interpret_multisentence(self, inputs, discourse_ids=None, question=False, verbose=False): """ Use Boxer to give a first order representation. :param inputs: list of list of str Input discourses to parse :param occur_index: bool Should predicates be occurrence indexed? :param discourse_ids: list of str Identifiers to be inserted to each occurrence-indexed predicate. :return: ``drt.AbstractDrs`` """ if discourse_ids is not None: assert len(inputs) == len(discourse_ids) assert reduce(operator.and_, (id is not None for id in discourse_ids)) use_disc_id = True else: discourse_ids = list(map(str, range(len(inputs)))) use_disc_id = False candc_out = self._call_candc(inputs, discourse_ids, question, verbose=verbose) boxer_out = self._call_boxer(candc_out, verbose=verbose) # if 'ERROR: input file contains no ccg/2 terms.' in boxer_out: # raise UnparseableInputException('Could not parse with candc: "%s"' % input_str) drs_dict = self._parse_to_drs_dict(boxer_out, use_disc_id) return [drs_dict.get(id, None) for id in discourse_ids] def _call_candc(self, inputs, discourse_ids, question, verbose=False): """ Call the ``candc`` binary with the given input. :param inputs: list of list of str Input discourses to parse :param discourse_ids: list of str Identifiers to be inserted to each occurrence-indexed predicate. :param filename: str A filename for the output file :return: stdout """ args = ['--models', os.path.join(self._candc_models_path, ['boxer','questions'][question]), '--candc-printer', 'boxer'] return self._call('\n'.join(sum((["'%s'" % id] + d for d,id in zip(inputs,discourse_ids)), [])), self._candc_bin, args, verbose) def _call_boxer(self, candc_out, verbose=False): """ Call the ``boxer`` binary with the given input. :param candc_out: str output from C&C parser :return: stdout """ f = None try: fd, temp_filename = tempfile.mkstemp(prefix='boxer-', suffix='.in', text=True) f = os.fdopen(fd, 'w') f.write(candc_out) finally: if f: f.close() args = ['--box', 'false', '--semantics', 'drs', '--flat', 'false', '--resolve', 'true', '--elimeq', ['false','true'][self._elimeq], '--format', 'prolog', '--instantiate', 'true', '--input', temp_filename] stdout = self._call(None, self._boxer_bin, args, verbose) os.remove(temp_filename) return stdout def _find_binary(self, name, bin_dir, verbose=False): return find_binary(name, path_to_bin=bin_dir, env_vars=['CANDCHOME'], url='http://svn.ask.it.usyd.edu.au/trac/candc/', binary_names=[name, name + '.exe'], verbose=verbose) def _call(self, input_str, binary, args=[], verbose=False): """ Call the binary with the given input. :param input_str: A string whose contents are used as stdin. :param binary: The location of the binary to call :param args: A list of command-line arguments. :return: stdout """ if verbose: print('Calling:', binary) print('Args:', args) print('Input:', input_str) print('Command:', binary + ' ' + ' '.join(args)) # Call via a subprocess if input_str is None: cmd = [binary] + args p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE) else: cmd = 'echo "%s" | %s %s' % (input_str, binary, ' '.join(args)) p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True) stdout, stderr = p.communicate() if verbose: print('Return code:', p.returncode) if stdout: print('stdout:\n', stdout, '\n') if stderr: print('stderr:\n', stderr, '\n') if p.returncode != 0: raise Exception('ERROR CALLING: %s %s\nReturncode: %d\n%s' % (binary, ' '.join(args), p.returncode, stderr)) return stdout def _parse_to_drs_dict(self, boxer_out, use_disc_id): lines = boxer_out.split('\n') drs_dict = {} i = 0 while i < len(lines): line = lines[i] if line.startswith('id('): comma_idx = line.index(',') discourse_id = line[3:comma_idx] if discourse_id[0] == "'" and discourse_id[-1] == "'": discourse_id = discourse_id[1:-1] drs_id = line[comma_idx+1:line.index(')')] i += 1 line = lines[i] assert line.startswith('sem(%s,' % drs_id) assert line.endswith(').') search_start = len('sem(%s,[' % drs_id) brace_count = 1 drs_start = -1 for j,c in enumerate(line[search_start:]): if(c == '['): brace_count += 1 if(c == ']'): brace_count -= 1 if(brace_count == 0): drs_start = search_start + j + 2 break assert drs_start > -1 drs_input = line[drs_start:-2].strip() parsed = self._parse_drs(drs_input, discourse_id, use_disc_id) drs_dict[discourse_id] = self._boxer_drs_interpreter.interpret(parsed) i += 1 return drs_dict def _parse_drs(self, drs_string, discourse_id, use_disc_id): return BoxerOutputDrsParser([None,discourse_id][use_disc_id]).parse(drs_string) class BoxerOutputDrsParser(DrtParser): def __init__(self, discourse_id=None): """ This class is used to parse the Prolog DRS output from Boxer into a hierarchy of python objects. """ DrtParser.__init__(self) self.discourse_id = discourse_id self.sentence_id_offset = None self.quote_chars = [("'", "'", "\\", False)] self._label_counter = None def parse(self, data, signature=None): self._label_counter = Counter(-1) return DrtParser.parse(self, data, signature) def get_all_symbols(self): return ['(', ')', ',', '[', ']',':'] def handle(self, tok, context): return self.handle_drs(tok) def attempt_adjuncts(self, expression, context): return expression def parse_condition(self, indices): """ Parse a DRS condition :return: list of ``AbstractDrs`` """ tok = self.token() accum = self.handle_condition(tok, indices) if accum is None: raise UnexpectedTokenException(tok) return accum def handle_drs(self, tok): if tok == 'drs': return self.parse_drs() elif tok in ['merge', 'smerge']: return self._handle_binary_expression(self._make_merge_expression)(None, []) elif tok in ['alfa']: return self._handle_alfa(self._make_merge_expression)(None, []) def handle_condition(self, tok, indices): """ Handle a DRS condition :param indices: list of int :return: list of ``AbstractDrs`` """ if tok == 'not': return [self._handle_not()] if tok == 'or': conds = [self._handle_binary_expression(self._make_or_expression)] elif tok == 'imp': conds = [self._handle_binary_expression(self._make_imp_expression)] elif tok == 'eq': conds = [self._handle_eq()] elif tok == 'prop': conds = [self._handle_prop()] elif tok == 'pred': conds = [self._handle_pred()] elif tok == 'named': conds = [self._handle_named()] elif tok == 'rel': conds = [self._handle_rel()] elif tok == 'timex': conds = self._handle_timex() elif tok == 'card': conds = [self._handle_card()] elif tok == 'whq': conds = [self._handle_whq()] else: conds = [] return sum([[cond(sent_index, word_indices) for cond in conds] for sent_index, word_indices in self._sent_and_word_indices(indices)], []) def _handle_not(self): self.assertToken(self.token(), '(') drs = self.parse_Expression(None) self.assertToken(self.token(), ')') return BoxerNot(drs) def _handle_pred(self): #pred(_G3943, dog, n, 0) self.assertToken(self.token(), '(') variable = self.parse_variable() self.assertToken(self.token(), ',') name = self.token() self.assertToken(self.token(), ',') pos = self.token() self.assertToken(self.token(), ',') sense = int(self.token()) self.assertToken(self.token(), ')') def _handle_pred_f(sent_index, word_indices): return BoxerPred(self.discourse_id, sent_index, word_indices, variable, name, pos, sense) return _handle_pred_f def _handle_named(self): #named(x0, john, per, 0) self.assertToken(self.token(), '(') variable = self.parse_variable() self.assertToken(self.token(), ',') name = self.token() self.assertToken(self.token(), ',') type = self.token() self.assertToken(self.token(), ',') sense = int(self.token()) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerNamed(self.discourse_id, sent_index, word_indices, variable, name, type, sense) def _handle_rel(self): #rel(_G3993, _G3943, agent, 0) self.assertToken(self.token(), '(') var1 = self.parse_variable() self.assertToken(self.token(), ',') var2 = self.parse_variable() self.assertToken(self.token(), ',') rel = self.token() self.assertToken(self.token(), ',') sense = int(self.token()) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerRel(self.discourse_id, sent_index, word_indices, var1, var2, rel, sense) def _handle_timex(self): #timex(_G18322, date([]: (+), []:'XXXX', [1004]:'04', []:'XX')) self.assertToken(self.token(), '(') arg = self.parse_variable() self.assertToken(self.token(), ',') new_conds = self._handle_time_expression(arg) self.assertToken(self.token(), ')') return new_conds def _handle_time_expression(self, arg): #date([]: (+), []:'XXXX', [1004]:'04', []:'XX') tok = self.token() self.assertToken(self.token(), '(') if tok == 'date': conds = self._handle_date(arg) elif tok == 'time': conds = self._handle_time(arg) else: return None self.assertToken(self.token(), ')') return [lambda sent_index, word_indices: BoxerPred(self.discourse_id, sent_index, word_indices, arg, tok, 'n', 0)] + \ [lambda sent_index, word_indices: cond for cond in conds] def _handle_date(self, arg): #[]: (+), []:'XXXX', [1004]:'04', []:'XX' conds = [] (sent_index, word_indices), = self._sent_and_word_indices(self._parse_index_list()) self.assertToken(self.token(), '(') pol = self.token() self.assertToken(self.token(), ')') conds.append(BoxerPred(self.discourse_id, sent_index, word_indices, arg, 'date_pol_%s' % (pol), 'a', 0)) self.assertToken(self.token(), ',') (sent_index, word_indices), = self._sent_and_word_indices(self._parse_index_list()) year = self.token() if year != 'XXXX': year = year.replace(':', '_') conds.append(BoxerPred(self.discourse_id, sent_index, word_indices, arg, 'date_year_%s' % (year), 'a', 0)) self.assertToken(self.token(), ',') (sent_index, word_indices), = self._sent_and_word_indices(self._parse_index_list()) month = self.token() if month != 'XX': conds.append(BoxerPred(self.discourse_id, sent_index, word_indices, arg, 'date_month_%s' % (month), 'a', 0)) self.assertToken(self.token(), ',') (sent_index, word_indices), = self._sent_and_word_indices(self._parse_index_list()) day = self.token() if day != 'XX': conds.append(BoxerPred(self.discourse_id, sent_index, word_indices, arg, 'date_day_%s' % (day), 'a', 0)) return conds def _handle_time(self, arg): #time([1018]:'18', []:'XX', []:'XX') conds = [] self._parse_index_list() hour = self.token() if hour != 'XX': conds.append(self._make_atom('r_hour_2',arg,hour)) self.assertToken(self.token(), ',') self._parse_index_list() min = self.token() if min != 'XX': conds.append(self._make_atom('r_min_2',arg,min)) self.assertToken(self.token(), ',') self._parse_index_list() sec = self.token() if sec != 'XX': conds.append(self._make_atom('r_sec_2',arg,sec)) return conds def _handle_card(self): #card(_G18535, 28, ge) self.assertToken(self.token(), '(') variable = self.parse_variable() self.assertToken(self.token(), ',') value = self.token() self.assertToken(self.token(), ',') type = self.token() self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerCard(self.discourse_id, sent_index, word_indices, variable, value, type) def _handle_prop(self): #prop(_G15949, drs(...)) self.assertToken(self.token(), '(') variable = self.parse_variable() self.assertToken(self.token(), ',') drs = self.parse_Expression(None) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerProp(self.discourse_id, sent_index, word_indices, variable, drs) def _parse_index_list(self): #[1001,1002]: indices = [] self.assertToken(self.token(), '[') while self.token(0) != ']': indices.append(self.parse_index()) if self.token(0) == ',': self.token() #swallow ',' self.token() #swallow ']' self.assertToken(self.token(), ':') return indices def parse_drs(self): #drs([[1001]:_G3943], # [[1002]:pred(_G3943, dog, n, 0)] # ) label = self._label_counter.get() self.assertToken(self.token(), '(') self.assertToken(self.token(), '[') refs = set() while self.token(0) != ']': indices = self._parse_index_list() refs.add(self.parse_variable()) if self.token(0) == ',': self.token() #swallow ',' self.token() #swallow ']' self.assertToken(self.token(), ',') self.assertToken(self.token(), '[') conds = [] while self.token(0) != ']': indices = self._parse_index_list() conds.extend(self.parse_condition(indices)) if self.token(0) == ',': self.token() #swallow ',' self.token() #swallow ']' self.assertToken(self.token(), ')') return BoxerDrs(label, list(refs), conds) def _handle_binary_expression(self, make_callback): self.assertToken(self.token(), '(') drs1 = self.parse_Expression(None) self.assertToken(self.token(), ',') drs2 = self.parse_Expression(None) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: make_callback(sent_index, word_indices, drs1, drs2) def _handle_alfa(self, make_callback): self.assertToken(self.token(), '(') type = self.token() self.assertToken(self.token(), ',') drs1 = self.parse_Expression(None) self.assertToken(self.token(), ',') drs2 = self.parse_Expression(None) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: make_callback(sent_index, word_indices, drs1, drs2) def _handle_eq(self): self.assertToken(self.token(), '(') var1 = self.parse_variable() self.assertToken(self.token(), ',') var2 = self.parse_variable() self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerEq(self.discourse_id, sent_index, word_indices, var1, var2) def _handle_whq(self): self.assertToken(self.token(), '(') self.assertToken(self.token(), '[') ans_types = [] while self.token(0) != ']': cat = self.token() self.assertToken(self.token(), ':') if cat == 'des': ans_types.append(self.token()) elif cat == 'num': ans_types.append('number') typ = self.token() if typ == 'cou': ans_types.append('count') else: ans_types.append(typ) else: ans_types.append(self.token()) self.token() #swallow the ']' self.assertToken(self.token(), ',') d1 = self.parse_Expression(None) self.assertToken(self.token(), ',') ref = self.parse_variable() self.assertToken(self.token(), ',') d2 = self.parse_Expression(None) self.assertToken(self.token(), ')') return lambda sent_index, word_indices: BoxerWhq(self.discourse_id, sent_index, word_indices, ans_types, d1, ref, d2) def _make_merge_expression(self, sent_index, word_indices, drs1, drs2): return BoxerDrs(drs1.label, drs1.refs + drs2.refs, drs1.conds + drs2.conds) def _make_or_expression(self, sent_index, word_indices, drs1, drs2): return BoxerOr(self.discourse_id, sent_index, word_indices, drs1, drs2) def _make_imp_expression(self, sent_index, word_indices, drs1, drs2): return BoxerDrs(drs1.label, drs1.refs, drs1.conds, drs2) def parse_variable(self): var = self.token() assert re.match('^[ex]\d+$', var), var return int(var[1:]) def parse_index(self): return int(self.token()) def _sent_and_word_indices(self, indices): """ :return: list of (sent_index, word_indices) tuples """ sent_indices = set((i / 1000)-1 for i in indices if i>=0) if sent_indices: pairs = [] for sent_index in sent_indices: word_indices = [(i % 1000)-1 for i in indices if sent_index == (i / 1000)-1] pairs.append((sent_index, word_indices)) return pairs else: word_indices = [(i % 1000)-1 for i in indices] return [(None, word_indices)] class BoxerDrsParser(DrtParser): """ Reparse the str form of subclasses of ``AbstractBoxerDrs`` """ def __init__(self, discourse_id=None): DrtParser.__init__(self) self.discourse_id = discourse_id def get_all_symbols(self): return [DrtTokens.OPEN, DrtTokens.CLOSE, DrtTokens.COMMA, DrtTokens.OPEN_BRACKET, DrtTokens.CLOSE_BRACKET] def attempt_adjuncts(self, expression, context): return expression def handle(self, tok, context): try: if tok == 'drs': self.assertNextToken(DrtTokens.OPEN) label = int(self.token()) self.assertNextToken(DrtTokens.COMMA) refs = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) conds = self.handle_conds(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerDrs(label, refs, conds) elif tok == 'pred': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) variable = int(self.token()) self.assertNextToken(DrtTokens.COMMA) name = self.token() self.assertNextToken(DrtTokens.COMMA) pos = self.token() self.assertNextToken(DrtTokens.COMMA) sense = int(self.token()) self.assertNextToken(DrtTokens.CLOSE) return BoxerPred(disc_id, sent_id, word_ids, variable, name, pos, sense) elif tok == 'named': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = int(self.token()) self.assertNextToken(DrtTokens.COMMA) word_ids = map(int, self.handle_refs()) self.assertNextToken(DrtTokens.COMMA) variable = int(self.token()) self.assertNextToken(DrtTokens.COMMA) name = self.token() self.assertNextToken(DrtTokens.COMMA) type = self.token() self.assertNextToken(DrtTokens.COMMA) sense = int(self.token()) self.assertNextToken(DrtTokens.CLOSE) return BoxerNamed(disc_id, sent_id, word_ids, variable, name, type, sense) elif tok == 'rel': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) var1 = int(self.token()) self.assertNextToken(DrtTokens.COMMA) var2 = int(self.token()) self.assertNextToken(DrtTokens.COMMA) rel = self.token() self.assertNextToken(DrtTokens.COMMA) sense = int(self.token()) self.assertNextToken(DrtTokens.CLOSE) return BoxerRel(disc_id, sent_id, word_ids, var1, var2, rel, sense) elif tok == 'prop': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = int(self.token()) self.assertNextToken(DrtTokens.COMMA) word_ids = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) variable = int(self.token()) self.assertNextToken(DrtTokens.COMMA) drs = self.parse_Expression(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerProp(disc_id, sent_id, word_ids, variable, drs) elif tok == 'not': self.assertNextToken(DrtTokens.OPEN) drs = self.parse_Expression(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerNot(drs) elif tok == 'imp': self.assertNextToken(DrtTokens.OPEN) drs1 = self.parse_Expression(None) self.assertNextToken(DrtTokens.COMMA) drs2 = self.parse_Expression(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerDrs(drs1.label, drs1.refs, drs1.conds, drs2) elif tok == 'or': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = map(int, self.handle_refs()) self.assertNextToken(DrtTokens.COMMA) drs1 = self.parse_Expression(None) self.assertNextToken(DrtTokens.COMMA) drs2 = self.parse_Expression(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerOr(disc_id, sent_id, word_ids, drs1, drs2) elif tok == 'eq': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) var1 = int(self.token()) self.assertNextToken(DrtTokens.COMMA) var2 = int(self.token()) self.assertNextToken(DrtTokens.CLOSE) return BoxerEq(disc_id, sent_id, word_ids, var1, var2) elif tok == 'card': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = map(int, self.handle_refs()) self.assertNextToken(DrtTokens.COMMA) var = int(self.token()) self.assertNextToken(DrtTokens.COMMA) value = self.token() self.assertNextToken(DrtTokens.COMMA) type = self.token() self.assertNextToken(DrtTokens.CLOSE) return BoxerCard(disc_id, sent_id, word_ids, var, value, type) elif tok == 'whq': self.assertNextToken(DrtTokens.OPEN) disc_id = (self.token(), self.discourse_id)[self.discourse_id is not None] self.assertNextToken(DrtTokens.COMMA) sent_id = self.nullableIntToken() self.assertNextToken(DrtTokens.COMMA) word_ids = list(map(int, self.handle_refs())) self.assertNextToken(DrtTokens.COMMA) ans_types = self.handle_refs() self.assertNextToken(DrtTokens.COMMA) drs1 = self.parse_Expression(None) self.assertNextToken(DrtTokens.COMMA) var = int(self.token()) self.assertNextToken(DrtTokens.COMMA) drs2 = self.parse_Expression(None) self.assertNextToken(DrtTokens.CLOSE) return BoxerWhq(disc_id, sent_id, word_ids, ans_types, drs1, var, drs2) except Exception as e: raise ParseException(self._currentIndex, str(e)) assert False, repr(tok) def nullableIntToken(self): t = self.token() return [None,int(t)][t != 'None'] def get_next_token_variable(self, description): try: return self.token() except ExpectedMoreTokensException as e: raise ExpectedMoreTokensException(e.index, 'Variable expected.') class AbstractBoxerDrs(object): def variables(self): """ :return: (set, set, set) """ variables, events, propositions = self._variables() return (variables - (events | propositions), events, propositions - events) def variable_types(self): vartypes = {} for t,vars in zip(('z','e','p'), self.variables()): for v in vars: vartypes[v] = t return vartypes def _variables(self): """ :return: (set, set, set) """ return (set(), set(), set()) def atoms(self): return set() def clean(self): return self def _clean_name(self, name): return name.replace('-','_').replace("'", "_") def renumber_sentences(self, f): return self def __hash__(self): return hash("%s" % self) @python_2_unicode_compatible class BoxerDrs(AbstractBoxerDrs): def __init__(self, label, refs, conds, consequent=None): AbstractBoxerDrs.__init__(self) self.label = label self.refs = refs self.conds = conds self.consequent = consequent def _variables(self): variables = (set(), set(), set()) for cond in self.conds: for s,v in zip(variables, cond._variables()): s.update(v) if self.consequent is not None: for s,v in zip(variables, self.consequent._variables()): s.update(v) return variables def atoms(self): atoms = reduce(operator.or_, (cond.atoms() for cond in self.conds), set()) if self.consequent is not None: atoms.update(self.consequent.atoms()) return atoms def clean(self): consequent = (self.consequent.clean() if self.consequent else None) return BoxerDrs(self.label, self.refs, [c.clean() for c in self.conds], consequent) def renumber_sentences(self, f): consequent = (self.consequent.renumber_sentences(f) if self.consequent else None) return BoxerDrs(self.label, self.refs, [c.renumber_sentences(f) for c in self.conds], consequent) def __repr__(self): s = 'drs(%s, [%s], [%s])' % (self.label, ', '.join("%s" % r for r in self.refs), ', '.join("%s" % c for c in self.conds)) if self.consequent is not None: s = 'imp(%s, %s)' % (s, self.consequent) return s def __eq__(self, other): return self.__class__ == other.__class__ and \ self.label == other.label and \ self.refs == other.refs and \ len(self.conds) == len(other.conds) and \ reduce(operator.and_, (c1==c2 for c1,c2 in zip(self.conds, other.conds))) and \ self.consequent == other.consequent def __ne__(self, other): return not self == other __hash__ = AbstractBoxerDrs.__hash__ @python_2_unicode_compatible class BoxerNot(AbstractBoxerDrs): def __init__(self, drs): AbstractBoxerDrs.__init__(self) self.drs = drs def _variables(self): return self.drs._variables() def atoms(self): return self.drs.atoms() def clean(self): return BoxerNot(self.drs.clean()) def renumber_sentences(self, f): return BoxerNot(self.drs.renumber_sentences(f)) def __repr__(self): return 'not(%s)' % (self.drs) def __eq__(self, other): return self.__class__ == other.__class__ and self.drs == other.drs def __ne__(self, other): return not self == other __hash__ = AbstractBoxerDrs.__hash__ @python_2_unicode_compatible class BoxerIndexed(AbstractBoxerDrs): def __init__(self, discourse_id, sent_index, word_indices): AbstractBoxerDrs.__init__(self) self.discourse_id = discourse_id self.sent_index = sent_index self.word_indices = word_indices def atoms(self): return set([self]) def __eq__(self, other): return self.__class__ == other.__class__ and \ self.discourse_id == other.discourse_id and \ self.sent_index == other.sent_index and \ self.word_indices == other.word_indices and \ reduce(operator.and_, (s==o for s,o in zip(self, other))) def __ne__(self, other): return not self == other __hash__ = AbstractBoxerDrs.__hash__ def __repr__(self): s = '%s(%s, %s, [%s]' % (self._pred(), self.discourse_id, self.sent_index, ', '.join("%s" % wi for wi in self.word_indices)) for v in self: s += ', %s' % v return s + ')' class BoxerPred(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var, name, pos, sense): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var = var self.name = name self.pos = pos self.sense = sense def _variables(self): return (set([self.var]), set(), set()) def change_var(self, var): return BoxerPred(self.discourse_id, self.sent_index, self.word_indices, var, self.name, self.pos, self.sense) def clean(self): return BoxerPred(self.discourse_id, self.sent_index, self.word_indices, self.var, self._clean_name(self.name), self.pos, self.sense) def renumber_sentences(self, f): new_sent_index = f(self.sent_index) return BoxerPred(self.discourse_id, new_sent_index, self.word_indices, self.var, self.name, self.pos, self.sense) def __iter__(self): return iter((self.var, self.name, self.pos, self.sense)) def _pred(self): return 'pred' class BoxerNamed(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var, name, type, sense): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var = var self.name = name self.type = type self.sense = sense def _variables(self): return (set([self.var]), set(), set()) def change_var(self, var): return BoxerNamed(self.discourse_id, self.sent_index, self.word_indices, var, self.name, self.type, self.sense) def clean(self): return BoxerNamed(self.discourse_id, self.sent_index, self.word_indices, self.var, self._clean_name(self.name), self.type, self.sense) def renumber_sentences(self, f): return BoxerNamed(self.discourse_id, f(self.sent_index), self.word_indices, self.var, self.name, self.type, self.sense) def __iter__(self): return iter((self.var, self.name, self.type, self.sense)) def _pred(self): return 'named' class BoxerRel(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var1, var2, rel, sense): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var1 = var1 self.var2 = var2 self.rel = rel self.sense = sense def _variables(self): return (set([self.var1, self.var2]), set(), set()) def clean(self): return BoxerRel(self.discourse_id, self.sent_index, self.word_indices, self.var1, self.var2, self._clean_name(self.rel), self.sense) def renumber_sentences(self, f): return BoxerRel(self.discourse_id, f(self.sent_index), self.word_indices, self.var1, self.var2, self.rel, self.sense) def __iter__(self): return iter((self.var1, self.var2, self.rel, self.sense)) def _pred(self): return 'rel' class BoxerProp(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var, drs): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var = var self.drs = drs def _variables(self): return tuple(map(operator.or_, (set(), set(), set([self.var])), self.drs._variables())) def referenced_labels(self): return set([self.drs]) def atoms(self): return self.drs.atoms() def clean(self): return BoxerProp(self.discourse_id, self.sent_index, self.word_indices, self.var, self.drs.clean()) def renumber_sentences(self, f): return BoxerProp(self.discourse_id, f(self.sent_index), self.word_indices, self.var, self.drs.renumber_sentences(f)) def __iter__(self): return iter((self.var, self.drs)) def _pred(self): return 'prop' class BoxerEq(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var1, var2): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var1 = var1 self.var2 = var2 def _variables(self): return (set([self.var1, self.var2]), set(), set()) def atoms(self): return set() def renumber_sentences(self, f): return BoxerEq(self.discourse_id, f(self.sent_index), self.word_indices, self.var1, self.var2) def __iter__(self): return iter((self.var1, self.var2)) def _pred(self): return 'eq' class BoxerCard(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, var, value, type): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.var = var self.value = value self.type = type def _variables(self): return (set([self.var]), set(), set()) def renumber_sentences(self, f): return BoxerCard(self.discourse_id, f(self.sent_index), self.word_indices, self.var, self.value, self.type) def __iter__(self): return iter((self.var, self.value, self.type)) def _pred(self): return 'card' class BoxerOr(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, drs1, drs2): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.drs1 = drs1 self.drs2 = drs2 def _variables(self): return tuple(map(operator.or_, self.drs1._variables(), self.drs2._variables())) def atoms(self): return self.drs1.atoms() | self.drs2.atoms() def clean(self): return BoxerOr(self.discourse_id, self.sent_index, self.word_indices, self.drs1.clean(), self.drs2.clean()) def renumber_sentences(self, f): return BoxerOr(self.discourse_id, f(self.sent_index), self.word_indices, self.drs1, self.drs2) def __iter__(self): return iter((self.drs1, self.drs2)) def _pred(self): return 'or' class BoxerWhq(BoxerIndexed): def __init__(self, discourse_id, sent_index, word_indices, ans_types, drs1, variable, drs2): BoxerIndexed.__init__(self, discourse_id, sent_index, word_indices) self.ans_types = ans_types self.drs1 = drs1 self.variable = variable self.drs2 = drs2 def _variables(self): return tuple(map(operator.or_, (set([self.variable]), set(), set()), self.drs1._variables(), self.drs2._variables())) def atoms(self): return self.drs1.atoms() | self.drs2.atoms() def clean(self): return BoxerWhq(self.discourse_id, self.sent_index, self.word_indices, self.ans_types, self.drs1.clean(), self.variable, self.drs2.clean()) def renumber_sentences(self, f): return BoxerWhq(self.discourse_id, f(self.sent_index), self.word_indices, self.ans_types, self.drs1, self.variable, self.drs2) def __iter__(self): return iter(('['+','.join(self.ans_types)+']', self.drs1, self.variable, self.drs2)) def _pred(self): return 'whq' class PassthroughBoxerDrsInterpreter(object): def interpret(self, ex): return ex class NltkDrtBoxerDrsInterpreter(object): def __init__(self, occur_index=False): self._occur_index = occur_index def interpret(self, ex): """ :param ex: ``AbstractBoxerDrs`` :return: ``AbstractDrs`` """ if isinstance(ex, BoxerDrs): drs = DRS([Variable('x%d' % r) for r in ex.refs], list(map(self.interpret, ex.conds))) if ex.label is not None: drs.label = Variable('x%d' % ex.label) if ex.consequent is not None: drs.consequent = self.interpret(ex.consequent) return drs elif isinstance(ex, BoxerNot): return DrtNegatedExpression(self.interpret(ex.drs)) elif isinstance(ex, BoxerPred): pred = self._add_occur_indexing('%s_%s' % (ex.pos, ex.name), ex) return self._make_atom(pred, 'x%d' % ex.var) elif isinstance(ex, BoxerNamed): pred = self._add_occur_indexing('ne_%s_%s' % (ex.type, ex.name), ex) return self._make_atom(pred, 'x%d' % ex.var) elif isinstance(ex, BoxerRel): pred = self._add_occur_indexing('%s' % (ex.rel), ex) return self._make_atom(pred, 'x%d' % ex.var1, 'x%d' % ex.var2) elif isinstance(ex, BoxerProp): return DrtProposition(Variable('x%d' % ex.var), self.interpret(ex.drs)) elif isinstance(ex, BoxerEq): return DrtEqualityExpression(DrtVariableExpression(Variable('x%d' % ex.var1)), DrtVariableExpression(Variable('x%d' % ex.var2))) elif isinstance(ex, BoxerCard): pred = self._add_occur_indexing('card_%s_%s' % (ex.type, ex.value), ex) return self._make_atom(pred, 'x%d' % ex.var) elif isinstance(ex, BoxerOr): return DrtOrExpression(self.interpret(ex.drs1), self.interpret(ex.drs2)) elif isinstance(ex, BoxerWhq): drs1 = self.interpret(ex.drs1) drs2 = self.interpret(ex.drs2) return DRS(drs1.refs + drs2.refs, drs1.conds + drs2.conds) assert False, '%s: %s' % (ex.__class__.__name__, ex) def _make_atom(self, pred, *args): accum = DrtVariableExpression(Variable(pred)) for arg in args: accum = DrtApplicationExpression(accum, DrtVariableExpression(Variable(arg))) return accum def _add_occur_indexing(self, base, ex): if self._occur_index and ex.sent_index is not None: if ex.discourse_id: base += '_%s' % ex.discourse_id base += '_s%s' % ex.sent_index base += '_w%s' % sorted(ex.word_indices)[0] return base class UnparseableInputException(Exception): pass if __name__ == '__main__': opts = OptionParser("usage: %prog TEXT [options]") opts.add_option("--verbose", "-v", help="display verbose logs", action="store_true", default=False, dest="verbose") opts.add_option("--fol", "-f", help="output FOL", action="store_true", default=False, dest="fol") opts.add_option("--question", "-q", help="input is a question", action="store_true", default=False, dest="question") opts.add_option("--occur", "-o", help="occurrence index", action="store_true", default=False, dest="occur_index") (options, args) = opts.parse_args() if len(args) != 1: opts.error("incorrect number of arguments") interpreter = NltkDrtBoxerDrsInterpreter(occur_index=options.occur_index) drs = Boxer(interpreter).interpret_multisentence(args[0].split(r'\n'), question=options.question, verbose=options.verbose) if drs is None: print(None) else: drs = drs.simplify().eliminate_equality() if options.fol: print(drs.fol().normalize()) else: drs.normalize().pprint()