spaCy/spacy/syntax/arc_eager.pyx

452 lines
16 KiB
Cython

# cython: profile=True
from __future__ import unicode_literals
import ctypes
import os
from ._state cimport State
from ._state cimport has_head, get_idx, get_s0, get_n0, get_left, get_right
from ._state cimport is_final, at_eol, pop_stack, push_stack, add_dep
from ._state cimport head_in_buffer, children_in_buffer
from ._state cimport head_in_stack, children_in_stack
from ._state cimport count_left_kids
from ..structs cimport TokenC
from .transition_system cimport do_func_t, get_cost_func_t
from .transition_system cimport move_cost_func_t, label_cost_func_t
from ..gold cimport GoldParse
from ..gold cimport GoldParseC
from libc.stdint cimport uint32_t
from libc.string cimport memcpy
from cymem.cymem cimport Pool
from .stateclass cimport StateClass
DEF NON_MONOTONIC = True
DEF USE_BREAK = True
cdef weight_t MIN_SCORE = -90000
# Break transition from here
# http://www.aclweb.org/anthology/P13-1074
cdef enum:
SHIFT
REDUCE
LEFT
RIGHT
BREAK
N_MOVES
MOVE_NAMES = [None] * N_MOVES
MOVE_NAMES[SHIFT] = 'S'
MOVE_NAMES[REDUCE] = 'D'
MOVE_NAMES[LEFT] = 'L'
MOVE_NAMES[RIGHT] = 'R'
MOVE_NAMES[BREAK] = 'B'
# Helper functions for the arc-eager oracle
cdef int push_cost(const State* st, const GoldParseC* gold, int target) except -1:
cdef StateClass stcls = StateClass(st.sent_len)
stcls.from_struct(st)
cdef int cost = 0
cdef int i, S_i
for i in range(stcls.stack_depth()):
S_i = stcls.S(i)
if gold.heads[target] == S_i:
cost += 1
if gold.heads[S_i] == target and (NON_MONOTONIC or not stcls.has_head(S_i)):
cost += 1
cost += Break.is_valid(stcls, -1) and Break.move_cost(st, gold) == 0
return cost
cdef int pop_cost(const State* st, const GoldParseC* gold, int target) except -1:
cdef StateClass stcls = StateClass(st.sent_len)
stcls.from_struct(st)
cdef int cost = 0
cdef int i, B_i
for i in range(stcls.buffer_length()):
B_i = stcls.B(i)
cost += gold.heads[B_i] == target
cost += gold.heads[target] == B_i
if gold.heads[B_i] == B_i or gold.heads[B_i] < target:
break
return cost
cdef int arc_cost(const State* st, const GoldParseC* gold, int head, int child) except -1:
cdef StateClass stcls = StateClass(st.sent_len)
stcls.from_struct(st)
if arc_is_gold(gold, head, child):
return 0
elif stcls.H(child) == gold.heads[child]:
return 1
elif gold.heads[child] >= stcls.B(0):
return 1
else:
return 0
cdef bint arc_is_gold(const GoldParseC* gold, int head, int child) except -1:
if gold.labels[child] == -1:
return True
elif _is_gold_root(gold, head) and _is_gold_root(gold, child):
return True
elif gold.heads[child] == head:
return True
else:
return False
cdef bint label_is_gold(const GoldParseC* gold, int head, int child, int label) except -1:
if gold.labels[child] == -1:
return True
elif label == -1:
return True
elif gold.labels[child] == label:
return True
else:
return False
cdef bint _is_gold_root(const GoldParseC* gold, int word) except -1:
return gold.labels[word] == -1 or gold.heads[word] == word
cdef class Shift:
@staticmethod
cdef bint is_valid(StateClass st, int label) except -1:
return not st.eol()
@staticmethod
cdef int transition(State* state, int label) except -1:
# Set the dep label, in case we need it after we reduce
if NON_MONOTONIC:
state.sent[state.i].dep = label
push_stack(state)
@staticmethod
cdef int cost(const State* s, const GoldParseC* gold, int label) except -1:
return Shift.move_cost(s, gold) + Shift.label_cost(s, gold, label)
@staticmethod
cdef int move_cost(const State* s, const GoldParseC* gold) except -1:
return push_cost(s, gold, s.i)
@staticmethod
cdef int label_cost(const State* s, const GoldParseC* gold, int label) except -1:
return 0
cdef class Reduce:
@staticmethod
cdef bint is_valid(StateClass st, int label) except -1:
if NON_MONOTONIC:
return st.stack_depth() >= 2 #and not missing_brackets(s)
else:
return st.stack_depth() >= 2 and st.has_head(st.S(0))
@staticmethod
cdef int transition(State* state, int label) except -1:
if NON_MONOTONIC and not has_head(get_s0(state)) and state.stack_len >= 2:
add_dep(state, state.stack[-1], state.stack[0], get_s0(state).dep)
pop_stack(state)
@staticmethod
cdef int cost(const State* s, const GoldParseC* gold, int label) except -1:
return Reduce.move_cost(s, gold) + Reduce.label_cost(s, gold, label)
@staticmethod
cdef int move_cost(const State* s, const GoldParseC* gold) except -1:
if NON_MONOTONIC:
return pop_cost(s, gold, s.stack[0])
else:
return children_in_buffer(s, s.stack[0], gold.heads)
@staticmethod
cdef int label_cost(const State* s, const GoldParseC* gold, int label) except -1:
return 0
cdef class LeftArc:
@staticmethod
cdef bint is_valid(StateClass st, int label) except -1:
if NON_MONOTONIC:
return st.stack_depth() >= 1 #and not missing_brackets(s)
else:
return st.stack_depth() >= 1 and not st.has_head(st.S(0))
@staticmethod
cdef int transition(State* state, int label) except -1:
# Interpret left-arcs from EOL as attachment to root
if at_eol(state):
add_dep(state, state.stack[0], state.stack[0], label)
else:
add_dep(state, state.i, state.stack[0], label)
pop_stack(state)
@staticmethod
cdef int cost(const State* s, const GoldParseC* gold, int label) except -1:
return LeftArc.move_cost(s, gold) + LeftArc.label_cost(s, gold, label)
@staticmethod
cdef int move_cost(const State* s, const GoldParseC* gold) except -1:
if arc_is_gold(gold, s.i, s.stack[0]):
return 0
else:
return pop_cost(s, gold, s.stack[0]) + arc_cost(s, gold, s.i, s.stack[0])
@staticmethod
cdef int label_cost(const State* s, const GoldParseC* gold, int label) except -1:
return arc_is_gold(gold, s.i, s.stack[0]) and not label_is_gold(gold, s.i, s.stack[0], label)
cdef class RightArc:
@staticmethod
cdef bint is_valid(StateClass st, int label) except -1:
return st.stack_depth() >= 1 and not st.eol()
@staticmethod
cdef int transition(State* state, int label) except -1:
add_dep(state, state.stack[0], state.i, label)
push_stack(state)
@staticmethod
cdef int cost(const State* s, const GoldParseC* gold, int label) except -1:
return RightArc.move_cost(s, gold) + RightArc.label_cost(s, gold, label)
@staticmethod
cdef int move_cost(const State* s, const GoldParseC* gold) except -1:
if arc_is_gold(gold, s.stack[0], s.i):
return 0
else:
return push_cost(s, gold, s.i) + arc_cost(s, gold, s.stack[0], s.i)
@staticmethod
cdef int label_cost(const State* s, const GoldParseC* gold, int label) except -1:
return arc_is_gold(gold, s.stack[0], s.i) and not label_is_gold(gold, s.stack[0], s.i, label)
cdef class Break:
@staticmethod
cdef bint is_valid(StateClass st, int label) except -1:
cdef int i
if not USE_BREAK:
return False
elif st.eol():
return False
elif st.stack_depth() < 1:
return False
elif NON_MONOTONIC:
return True
else:
# In the Break transition paper, they have this constraint that prevents
# Break if stack is disconnected. But, if we're doing non-monotonic parsing,
# we prefer to relax this constraint. This is helpful in parsing whole
# documents, because then we don't get stuck with words on the stack.
seen_headless = False
for i in range(st.stack_depth()):
if not st.has_head(st.S(i)):
if seen_headless:
return False
else:
seen_headless = True
# TODO: Constituency constraints
return True
@staticmethod
cdef int transition(State* state, int label) except -1:
state.sent[state.i-1].sent_end = True
while state.stack_len != 0:
if get_s0(state).head == 0:
get_s0(state).dep = label
state.stack -= 1
state.stack_len -= 1
@staticmethod
cdef int cost(const State* s, const GoldParseC* gold, int label) except -1:
return Break.move_cost(s, gold) + Break.label_cost(s, gold, label)
@staticmethod
cdef int move_cost(const State* s, const GoldParseC* gold) except -1:
# When we break, we Reduce all of the words on the stack.
cdef int cost = 0
# Number of deps between S0...Sn and N0...Nn
for i in range(s.i, s.sent_len):
cost += children_in_stack(s, i, gold.heads)
cost += head_in_stack(s, i, gold.heads)
return cost
@staticmethod
cdef int label_cost(const State* s, const GoldParseC* gold, int label) except -1:
return 0
cdef class ArcEager(TransitionSystem):
@classmethod
def get_labels(cls, gold_parses):
move_labels = {SHIFT: {'': True}, REDUCE: {'': True}, RIGHT: {},
LEFT: {'ROOT': True}, BREAK: {'ROOT': True}}
for raw_text, sents in gold_parses:
for (ids, words, tags, heads, labels, iob), ctnts in sents:
for child, head, label in zip(ids, heads, labels):
if label != 'ROOT':
if head < child:
move_labels[RIGHT][label] = True
elif head > child:
move_labels[LEFT][label] = True
return move_labels
cdef int preprocess_gold(self, GoldParse gold) except -1:
for i in range(gold.length):
if gold.heads[i] is None: # Missing values
gold.c.heads[i] = i
gold.c.labels[i] = -1
else:
gold.c.heads[i] = gold.heads[i]
gold.c.labels[i] = self.strings[gold.labels[i]]
for end, brackets in gold.brackets.items():
for start, label_strs in brackets.items():
gold.c.brackets[start][end] = 1
for label_str in label_strs:
# Add the encoded label to the set
gold.brackets[end][start].add(self.strings[label_str])
cdef Transition lookup_transition(self, object name) except *:
if '-' in name:
move_str, label_str = name.split('-', 1)
label = self.label_ids[label_str]
else:
label = 0
move = MOVE_NAMES.index(move_str)
for i in range(self.n_moves):
if self.c[i].move == move and self.c[i].label == label:
return self.c[i]
def move_name(self, int move, int label):
label_str = self.strings[label]
if label_str:
return MOVE_NAMES[move] + '-' + label_str
else:
return MOVE_NAMES[move]
cdef Transition init_transition(self, int clas, int move, int label) except *:
# TODO: Apparent Cython bug here when we try to use the Transition()
# constructor with the function pointers
cdef Transition t
t.score = 0
t.clas = clas
t.move = move
t.label = label
if move == SHIFT:
t.is_valid = Shift.is_valid
t.do = Shift.transition
t.get_cost = Shift.cost
elif move == REDUCE:
t.is_valid = Reduce.is_valid
t.do = Reduce.transition
t.get_cost = Reduce.cost
elif move == LEFT:
t.is_valid = LeftArc.is_valid
t.do = LeftArc.transition
t.get_cost = LeftArc.cost
elif move == RIGHT:
t.is_valid = RightArc.is_valid
t.do = RightArc.transition
t.get_cost = RightArc.cost
elif move == BREAK:
t.is_valid = Break.is_valid
t.do = Break.transition
t.get_cost = Break.cost
else:
raise Exception(move)
return t
cdef int initialize_state(self, State* state) except -1:
push_stack(state)
cdef int finalize_state(self, State* state) except -1:
cdef int root_label = self.strings['ROOT']
for i in range(state.sent_len):
if state.sent[i].head == 0 and state.sent[i].dep == 0:
state.sent[i].dep = root_label
cdef int set_valid(self, bint* output, StateClass stcls) except -1:
cdef bint[N_MOVES] is_valid
is_valid[SHIFT] = Shift.is_valid(stcls, -1)
is_valid[REDUCE] = Reduce.is_valid(stcls, -1)
is_valid[LEFT] = LeftArc.is_valid(stcls, -1)
is_valid[RIGHT] = RightArc.is_valid(stcls, -1)
is_valid[BREAK] = Break.is_valid(stcls, -1)
cdef int i
for i in range(self.n_moves):
output[i] = is_valid[self.c[i].move]
cdef int set_costs(self, int* output, const State* s, GoldParse gold) except -1:
cdef int i, move, label
cdef label_cost_func_t[N_MOVES] label_cost_funcs
cdef move_cost_func_t[N_MOVES] move_cost_funcs
cdef int[N_MOVES] move_costs
for i in range(N_MOVES):
move_costs[i] = -1
move_cost_funcs[SHIFT] = Shift.move_cost
move_cost_funcs[REDUCE] = Reduce.move_cost
move_cost_funcs[LEFT] = LeftArc.move_cost
move_cost_funcs[RIGHT] = RightArc.move_cost
move_cost_funcs[BREAK] = Break.move_cost
label_cost_funcs[SHIFT] = Shift.label_cost
label_cost_funcs[REDUCE] = Reduce.label_cost
label_cost_funcs[LEFT] = LeftArc.label_cost
label_cost_funcs[RIGHT] = RightArc.label_cost
label_cost_funcs[BREAK] = Break.label_cost
cdef int* labels = gold.c.labels
cdef int* heads = gold.c.heads
cdef StateClass stcls = StateClass(s.sent_len)
stcls.from_struct(s)
self.set_valid(self._is_valid, stcls)
for i in range(self.n_moves):
if not self._is_valid[i]:
output[i] = 9000
else:
move = self.c[i].move
label = self.c[i].label
if move_costs[move] == -1:
move_costs[move] = move_cost_funcs[move](s, &gold.c)
output[i] = move_costs[move] + label_cost_funcs[move](s, &gold.c, label)
cdef Transition best_valid(self, const weight_t* scores, StateClass stcls) except *:
cdef bint[N_MOVES] is_valid
is_valid[SHIFT] = Shift.is_valid(stcls, -1)
is_valid[REDUCE] = Reduce.is_valid(stcls, -1)
is_valid[LEFT] = LeftArc.is_valid(stcls, -1)
is_valid[RIGHT] = RightArc.is_valid(stcls, -1)
is_valid[BREAK] = Break.is_valid(stcls, -1)
cdef Transition best
cdef weight_t score = MIN_SCORE
cdef int i
for i in range(self.n_moves):
if scores[i] > score and is_valid[self.c[i].move]:
best = self.c[i]
score = scores[i]
assert best.clas < self.n_moves
assert score > MIN_SCORE
# Label Shift moves with the best Right-Arc label, for non-monotonic
# actions
if best.move == SHIFT:
score = MIN_SCORE
for i in range(self.n_moves):
if self.c[i].move == RIGHT and scores[i] > score:
best.label = self.c[i].label
score = scores[i]
return best