spaCy/spacy/syntax/transition_system.pyx
2017-05-27 15:52:20 -05:00

149 lines
4.9 KiB
Cython

# cython: infer_types=True
# coding: utf-8
from __future__ import unicode_literals
from cpython.ref cimport PyObject, Py_INCREF, Py_XDECREF
from cymem.cymem cimport Pool
from thinc.typedefs cimport weight_t
from collections import defaultdict, OrderedDict
from ..structs cimport TokenC
from .stateclass cimport StateClass
from ..attrs cimport TAG, HEAD, DEP, ENT_TYPE, ENT_IOB
cdef weight_t MIN_SCORE = -90000
class OracleError(Exception):
pass
cdef void* _init_state(Pool mem, int length, void* tokens) except NULL:
cdef StateClass st = StateClass.init(<const TokenC*>tokens, length)
Py_INCREF(st)
return <void*>st
cdef class TransitionSystem:
def __init__(self, StringStore string_table, labels_by_action):
self.mem = Pool()
self.strings = string_table
self.n_moves = 0
self._size = 100
self.c = <Transition*>self.mem.alloc(self._size, sizeof(Transition))
for action, label_strs in labels_by_action.items():
for label_str in label_strs:
self.add_action(int(action), label_str)
self.root_label = self.strings['ROOT']
self.init_beam_state = _init_state
def __reduce__(self):
labels_by_action = OrderedDict()
cdef Transition t
for trans in self.c[:self.n_moves]:
label_str = self.strings[trans.label]
labels_by_action.setdefault(trans.move, []).append(label_str)
return (self.__class__,
(self.strings, labels_by_action),
None, None)
def init_batch(self, docs):
cdef StateClass state
states = []
offset = 0
for doc in docs:
state = StateClass(doc, offset=offset)
self.initialize_state(state.c)
states.append(state)
offset += len(doc)
return states
def get_oracle_sequence(self, doc, GoldParse gold):
cdef Pool mem = Pool()
costs = <float*>mem.alloc(self.n_moves, sizeof(float))
is_valid = <int*>mem.alloc(self.n_moves, sizeof(int))
cdef StateClass state = StateClass(doc, offset=0)
self.initialize_state(state.c)
history = []
while not state.is_final():
self.set_costs(is_valid, costs, state, gold)
for i in range(self.n_moves):
if is_valid[i] and costs[i] <= 0:
action = self.c[i]
history.append(i)
action.do(state.c, action.label)
break
else:
print(gold.words)
print(gold.ner)
print(history)
raise ValueError("Could not find gold move")
return history
cdef int initialize_state(self, StateC* state) nogil:
pass
cdef int finalize_state(self, StateC* state) nogil:
pass
def finalize_doc(self, doc):
pass
def preprocess_gold(self, GoldParse gold):
raise NotImplementedError
cdef Transition lookup_transition(self, object name) except *:
raise NotImplementedError
cdef Transition init_transition(self, int clas, int move, int label) except *:
raise NotImplementedError
def is_valid(self, StateClass stcls, move_name):
action = self.lookup_transition(move_name)
return action.is_valid(stcls.c, action.label)
cdef int set_valid(self, int* is_valid, const StateC* st) nogil:
cdef int i
for i in range(self.n_moves):
is_valid[i] = self.c[i].is_valid(st, self.c[i].label)
cdef int set_costs(self, int* is_valid, weight_t* costs,
StateClass stcls, GoldParse gold) except -1:
cdef int i
self.set_valid(is_valid, stcls.c)
cdef int n_gold = 0
for i in range(self.n_moves):
if is_valid[i]:
costs[i] = self.c[i].get_cost(stcls, &gold.c, self.c[i].label)
n_gold += costs[i] <= 0
else:
costs[i] = 9000
if n_gold <= 0:
print(gold.words)
print(gold.ner)
raise ValueError(
"Could not find a gold-standard action to supervise "
"the entity recognizer\n"
"The transition system has %d actions.\n"
"%s" % (self.n_moves))
def add_action(self, int action, label):
if not isinstance(label, int):
label = self.strings[label]
# Check we're not creating a move we already have, so that this is
# idempotent
for trans in self.c[:self.n_moves]:
if trans.move == action and trans.label == label:
return 0
if self.n_moves >= self._size:
self._size *= 2
self.c = <Transition*>self.mem.realloc(self.c, self._size * sizeof(self.c[0]))
self.c[self.n_moves] = self.init_transition(self.n_moves, action, label)
self.n_moves += 1
return 1