spaCy/spacy/syntax/transition_system.pyx
2017-03-16 11:59:11 -05:00

110 lines
3.7 KiB
Cython

# cython: infer_types=True
from cymem.cymem cimport Pool
from thinc.typedefs cimport weight_t
from collections import defaultdict
from ..structs cimport TokenC
from .stateclass cimport StateClass
from ..attrs cimport TAG, HEAD, DEP, ENT_TYPE, ENT_IOB
from cpython.ref cimport PyObject, Py_INCREF, Py_XDECREF
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, dict labels_by_action, _freqs=None):
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 sorted(labels_by_action.items()):
for label_str in sorted(label_strs):
self.add_action(int(action), label_str)
self.root_label = self.strings['ROOT']
self.freqs = {} if _freqs is None else _freqs
for attr in (TAG, HEAD, DEP, ENT_TYPE, ENT_IOB):
self.freqs[attr] = defaultdict(int)
self.freqs[attr][0] = 1
# Ensure we've seen heads. Need an official dependency length limit...
for i in range(10024):
self.freqs[HEAD][i] = 1
self.freqs[HEAD][-i] = 1
self.init_beam_state = _init_state
def __reduce__(self):
labels_by_action = {}
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, self.freqs),
None, None)
cdef int initialize_state(self, StateC* state) nogil:
pass
cdef int finalize_state(self, StateC* state) nogil:
pass
def finalize_doc(self, doc):
pass
cdef int preprocess_gold(self, GoldParse gold) except -1:
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)
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)
else:
costs[i] = 9000
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