# Natural Language Toolkit: Interface to Boxer
# <http://svn.ask.it.usyd.edu.au/trac/candc/wiki/boxer>
#
# Author: Dan Garrette <dhgarrette@gmail.com>
#
# Copyright (C) 2001-2023 NLTK Project
# URL: <https://www.nltk.org/>
# 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 CANDC 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/
"""
import operator
import os
import re
import subprocess
import tempfile
from functools import reduce
from optparse import OptionParser
from nltk.internals import find_binary
from nltk.sem.drt import (
DRS,
DrtApplicationExpression,
DrtEqualityExpression,
DrtNegatedExpression,
DrtOrExpression,
DrtParser,
DrtProposition,
DrtTokens,
DrtVariableExpression,
)
from nltk.sem.logic import (
ExpectedMoreTokensException,
LogicalExpressionException,
UnexpectedTokenException,
Variable,
)
[docs]class Boxer:
"""
This class is an interface to Johan Bos's program Boxer, a wide-coverage
semantic parser that produces Discourse Representation Structures (DRSs).
"""
[docs] def __init__(
self,
boxer_drs_interpreter=None,
elimeq=False,
bin_dir=None,
verbose=False,
resolve=True,
):
"""
: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.
:param resolve: When set to true, Boxer will resolve all anaphoric DRSs and perform merge-reduction.
Resolution follows Van der Sandt's theory of binding and accommodation.
"""
if boxer_drs_interpreter is None:
boxer_drs_interpreter = NltkDrtBoxerDrsInterpreter()
self._boxer_drs_interpreter = boxer_drs_interpreter
self._resolve = resolve
self._elimeq = elimeq
self.set_bin_dir(bin_dir, verbose)
[docs] 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)
[docs] 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.DrtExpression``
"""
discourse_ids = [discourse_id] if discourse_id is not None else None
(d,) = self.interpret_multi_sents([[input]], discourse_ids, question, verbose)
if not d:
raise Exception(f'Unable to interpret: "{input}"')
return d
[docs] def interpret_multi(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.DrtExpression``
"""
discourse_ids = [discourse_id] if discourse_id is not None else None
(d,) = self.interpret_multi_sents([input], discourse_ids, question, verbose)
if not d:
raise Exception(f'Unable to interpret: "{input}"')
return d
[docs] def interpret_sents(
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.DrtExpression``
"""
return self.interpret_multi_sents(
[[input] for input in inputs], discourse_ids, question, verbose
)
[docs] def interpret_multi_sents(
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.DrtExpression``
"""
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(
([f"<META>'{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.decode("utf-8"))
finally:
if f:
f.close()
args = [
"--box",
"false",
"--semantics",
"drs",
#'--flat', 'false', # removed from boxer
"--resolve",
["false", "true"][self._resolve],
"--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=["CANDC"],
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 "{}" | {} {}'.format(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: {} {}\nReturncode: {}\n{}".format(
binary, " ".join(args), p.returncode, stderr
)
)
return stdout
def _parse_to_drs_dict(self, boxer_out, use_disc_id):
lines = boxer_out.decode("utf-8").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(f"sem({drs_id},")
if line[-4:] == "').'":
line = line[:-4] + ")."
assert line.endswith(")."), f"can't parse line: {line}"
search_start = len(f"sem({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 + 1
if line[drs_start : drs_start + 3] == "','":
drs_start = drs_start + 3
else:
drs_start = drs_start + 1
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)
[docs]class BoxerOutputDrsParser(DrtParser):
[docs] 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)]
[docs] def parse(self, data, signature=None):
return DrtParser.parse(self, data, signature)
[docs] def get_all_symbols(self):
return ["(", ")", ",", "[", "]", ":"]
[docs] def handle(self, tok, context):
return self.handle_drs(tok)
[docs] def attempt_adjuncts(self, expression, context):
return expression
[docs] def parse_condition(self, indices):
"""
Parse a DRS condition
:return: list of ``DrtExpression``
"""
tok = self.token()
accum = self.handle_condition(tok, indices)
if accum is None:
raise UnexpectedTokenException(tok)
return accum
[docs] 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, [])
[docs] def handle_condition(self, tok, indices):
"""
Handle a DRS condition
:param indices: list of int
:return: list of ``DrtExpression``
"""
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()]
elif tok == "duplex":
conds = [self._handle_duplex()]
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.process_next_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_duplex(self):
# duplex(whq, drs(...), var, drs(...))
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(), "whq")
self.assertToken(self.token(), ",")
d1 = self.process_next_expression(None)
self.assertToken(self.token(), ",")
ref = self.parse_variable()
self.assertToken(self.token(), ",")
d2 = self.process_next_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 _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 = self.token() # as per boxer rev 2554
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,
f"date_pol_{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,
f"date_year_{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,
f"date_month_{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,
f"date_day_{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.process_next_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
[docs] def parse_drs(self):
# drs([[1001]:_G3943],
# [[1002]:pred(_G3943, dog, n, 0)]
# )
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(list(refs), conds)
def _handle_binary_expression(self, make_callback):
self.assertToken(self.token(), "(")
drs1 = self.process_next_expression(None)
self.assertToken(self.token(), ",")
drs2 = self.process_next_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.process_next_expression(None)
self.assertToken(self.token(), ",")
drs2 = self.process_next_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.process_next_expression(None)
self.assertToken(self.token(), ",")
ref = self.parse_variable()
self.assertToken(self.token(), ",")
d2 = self.process_next_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.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.refs, drs1.conds, drs2)
[docs] def parse_variable(self):
var = self.token()
assert re.match(r"^[exps]\d+$", var), var
return var
[docs] 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 = {(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)]
[docs]class BoxerDrsParser(DrtParser):
"""
Reparse the str form of subclasses of ``AbstractBoxerDrs``
"""
[docs] def __init__(self, discourse_id=None):
DrtParser.__init__(self)
self.discourse_id = discourse_id
[docs] def get_all_symbols(self):
return [
DrtTokens.OPEN,
DrtTokens.CLOSE,
DrtTokens.COMMA,
DrtTokens.OPEN_BRACKET,
DrtTokens.CLOSE_BRACKET,
]
[docs] def attempt_adjuncts(self, expression, context):
return expression
[docs] 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)
if tok == "pred":
self.assertNextToken(DrtTokens.OPEN)
disc_id = (
self.discourse_id if self.discourse_id is not None else self.token()
)
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.discourse_id if self.discourse_id is not None else self.token()
)
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.discourse_id if self.discourse_id is not None else self.token()
)
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.discourse_id if self.discourse_id is not None else self.token()
)
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.process_next_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.process_next_expression(None)
self.assertNextToken(DrtTokens.CLOSE)
return BoxerNot(drs)
elif tok == "imp":
self.assertNextToken(DrtTokens.OPEN)
drs1 = self.process_next_expression(None)
self.assertNextToken(DrtTokens.COMMA)
drs2 = self.process_next_expression(None)
self.assertNextToken(DrtTokens.CLOSE)
return BoxerDrs(drs1.refs, drs1.conds, drs2)
elif tok == "or":
self.assertNextToken(DrtTokens.OPEN)
disc_id = (
self.discourse_id if self.discourse_id is not None else self.token()
)
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.process_next_expression(None)
self.assertNextToken(DrtTokens.COMMA)
drs2 = self.process_next_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.discourse_id if self.discourse_id is not None else self.token()
)
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.discourse_id if self.discourse_id is not None else self.token()
)
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.discourse_id if self.discourse_id is not None else self.token()
)
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.process_next_expression(None)
self.assertNextToken(DrtTokens.COMMA)
var = int(self.token())
self.assertNextToken(DrtTokens.COMMA)
drs2 = self.process_next_expression(None)
self.assertNextToken(DrtTokens.CLOSE)
return BoxerWhq(disc_id, sent_id, word_ids, ans_types, drs1, var, drs2)
except Exception as e:
raise LogicalExpressionException(self._currentIndex, str(e)) from e
assert False, repr(tok)
[docs] def nullableIntToken(self):
t = self.token()
return int(t) if t != "None" else None
[docs] def get_next_token_variable(self, description):
try:
return self.token()
except ExpectedMoreTokensException as e:
raise ExpectedMoreTokensException(e.index, "Variable expected.") from e
[docs]class AbstractBoxerDrs:
[docs] def variables(self):
"""
:return: (set<variables>, set<events>, set<propositions>)
"""
variables, events, propositions = self._variables()
return (variables - (events | propositions), events, propositions - events)
[docs] 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<variables>, set<events>, set<propositions>)
"""
return (set(), set(), set())
[docs] def atoms(self):
return set()
[docs] def clean(self):
return self
def _clean_name(self, name):
return name.replace("-", "_").replace("'", "_")
[docs] def renumber_sentences(self, f):
return self
def __hash__(self):
return hash(f"{self}")
[docs]class BoxerDrs(AbstractBoxerDrs):
[docs] def __init__(self, refs, conds, consequent=None):
AbstractBoxerDrs.__init__(self)
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
[docs] 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
[docs] def clean(self):
consequent = self.consequent.clean() if self.consequent else None
return BoxerDrs(self.refs, [c.clean() for c in self.conds], consequent)
[docs] def renumber_sentences(self, f):
consequent = self.consequent.renumber_sentences(f) if self.consequent else None
return BoxerDrs(
self.refs, [c.renumber_sentences(f) for c in self.conds], consequent
)
def __repr__(self):
s = "drs([{}], [{}])".format(
", ".join("%s" % r for r in self.refs),
", ".join("%s" % c for c in self.conds),
)
if self.consequent is not None:
s = f"imp({s}, {self.consequent})"
return s
def __eq__(self, other):
return (
self.__class__ == other.__class__
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__
[docs]class BoxerNot(AbstractBoxerDrs):
[docs] def __init__(self, drs):
AbstractBoxerDrs.__init__(self)
self.drs = drs
def _variables(self):
return self.drs._variables()
[docs] def atoms(self):
return self.drs.atoms()
[docs] def clean(self):
return BoxerNot(self.drs.clean())
[docs] 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__
[docs]class BoxerIndexed(AbstractBoxerDrs):
[docs] 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
[docs] def atoms(self):
return {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 = "{}({}, {}, [{}]".format(
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 + ")"
[docs]class BoxerPred(BoxerIndexed):
[docs] 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 ({self.var}, set(), set())
[docs] def change_var(self, var):
return BoxerPred(
self.discourse_id,
self.sent_index,
self.word_indices,
var,
self.name,
self.pos,
self.sense,
)
[docs] 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,
)
[docs] 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"
[docs]class BoxerNamed(BoxerIndexed):
[docs] 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 ({self.var}, set(), set())
[docs] def change_var(self, var):
return BoxerNamed(
self.discourse_id,
self.sent_index,
self.word_indices,
var,
self.name,
self.type,
self.sense,
)
[docs] 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,
)
[docs] 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"
[docs]class BoxerRel(BoxerIndexed):
[docs] 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 ({self.var1, self.var2}, set(), set())
[docs] 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,
)
[docs] 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"
[docs]class BoxerProp(BoxerIndexed):
[docs] 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(), {self.var}), self.drs._variables())
)
[docs] def referenced_labels(self):
return {self.drs}
[docs] def atoms(self):
return self.drs.atoms()
[docs] def clean(self):
return BoxerProp(
self.discourse_id,
self.sent_index,
self.word_indices,
self.var,
self.drs.clean(),
)
[docs] 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"
[docs]class BoxerEq(BoxerIndexed):
[docs] 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 ({self.var1, self.var2}, set(), set())
[docs] def atoms(self):
return set()
[docs] 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"
[docs]class BoxerCard(BoxerIndexed):
[docs] 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 ({self.var}, set(), set())
[docs] 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"
[docs]class BoxerOr(BoxerIndexed):
[docs] 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()))
[docs] def atoms(self):
return self.drs1.atoms() | self.drs2.atoms()
[docs] def clean(self):
return BoxerOr(
self.discourse_id,
self.sent_index,
self.word_indices,
self.drs1.clean(),
self.drs2.clean(),
)
[docs] 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"
[docs]class BoxerWhq(BoxerIndexed):
[docs] 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_,
({self.variable}, set(), set()),
self.drs1._variables(),
self.drs2._variables(),
)
)
[docs] def atoms(self):
return self.drs1.atoms() | self.drs2.atoms()
[docs] 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(),
)
[docs] 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"
[docs]class PassthroughBoxerDrsInterpreter:
[docs] def interpret(self, ex):
return ex
[docs]class NltkDrtBoxerDrsInterpreter:
[docs] def __init__(self, occur_index=False):
self._occur_index = occur_index
[docs] def interpret(self, ex):
"""
:param ex: ``AbstractBoxerDrs``
:return: ``DrtExpression``
"""
if isinstance(ex, BoxerDrs):
drs = DRS(
[Variable(r) for r in ex.refs], list(map(self.interpret, ex.conds))
)
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(f"{ex.pos}_{ex.name}", ex)
return self._make_atom(pred, ex.var)
elif isinstance(ex, BoxerNamed):
pred = self._add_occur_indexing(f"ne_{ex.type}_{ex.name}", ex)
return self._make_atom(pred, ex.var)
elif isinstance(ex, BoxerRel):
pred = self._add_occur_indexing("%s" % (ex.rel), ex)
return self._make_atom(pred, ex.var1, ex.var2)
elif isinstance(ex, BoxerProp):
return DrtProposition(Variable(ex.var), self.interpret(ex.drs))
elif isinstance(ex, BoxerEq):
return DrtEqualityExpression(
DrtVariableExpression(Variable(ex.var1)),
DrtVariableExpression(Variable(ex.var2)),
)
elif isinstance(ex, BoxerCard):
pred = self._add_occur_indexing(f"card_{ex.type}_{ex.value}", ex)
return self._make_atom(pred, 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, f"{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
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_multi(
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.pretty_print()