def predict(self, enc_hidden, context, context_lengths, batch, beam_size, max_code_length, generator, replace_unk, vis_params):
# This decoder does not have input feeding. Parent state replces that
decState = DecoderState(
enc_hidden, #encoder hidden
Variable(torch.zeros(1, 1, self.opt.rnn_size).cuda(), requires_grad=False) # parent state
)
# Repeat everything beam_size times.
def rvar(a, beam_size):
return Variable(a.repeat(beam_size, 1, 1), volatile=True)
context = rvar(context.data, beam_size)
context_lengths = context_lengths.repeat(beam_size)
decState.repeat_beam_size_times(beam_size) # TODO: get back to this
# Use only one beam
beam = TreeBeam(beam_size, True, self.vocabs, self.opt.rnn_size)
for count in range(0, max_code_length): # We will break when we have the required number of terminals
# to be consistent with seq2seq
if beam.done(): # TODO: fix b.done
break
# Construct batch x beam_size nxt words.
# Get all the pending current beam words and arrange for forward.
# Uses the start symbol in the beginning
inp = beam.getCurrentState() # Should return a batch of the frontier
# Run one step., decState gets automatically updated
output, attn, copy_attn = self.forward(inp, context, context_lengths, decState)
scores = generator(bottle(output), bottle(copy_attn), batch['src_map'], inp) #generator needs the non-terminals
out = generator.collapseCopyScores(unbottle(scores.data.clone(), beam_size), batch) # needs seq2seq from batch
out = out.log()
# beam x tgt_vocab
beam.advance(out[:, 0], attn.data[:, 0], output)
decState.beam_update(beam.getCurrentOrigin(), beam_size)
score, times, k = beam.getFinal() # times is the length of the prediction
#hyp, att = beam.getHyp(times, k)
goldNl = self.vocabs['seq2seq'].addStartOrEnd(batch['raw_seq2seq'][0]) # because batch = 1
goldCode = self.vocabs['code'].addStartOrEnd(batch['raw_code'][0])
# goldProd = self.vocabs['next_rules'].addStartOrEnd(batch['raw_next_rules'][0])
predictions = []
for score, times, k in beam.finished:
hyp, att = beam.getHyp(times, k)
predSent = self.buildTargetTokens(
hyp,
self.vocabs,
goldNl,
att,
batch['seq2seq_vocab'][0],
replace_unk
)
predSent = ProdDecoder.rulesToCode(predSent)
predictions.append(Prediction(goldNl, goldCode, predSent, att, score))
return predictions
def computeLoss(self, scores, batch):
batch_size = batch['seq2seq'].size(0)
target = Variable(batch['next_rules'].contiguous().cuda().view(-1),
requires_grad=False)
if self.opt.decoder_type == "prod":
align = Variable(
batch['next_rules_in_src_nums'].contiguous().cuda().view(-1),
requires_grad=False)
align_unk = batch['seq2seq_vocab'][0].stoi['<unk>']
elif self.opt.decoder_type in ["concode"]:
align = Variable(batch['concode_next_rules_in_src_nums'].
contiguous().cuda().view(-1),
requires_grad=False)
align_unk = batch['concode_vocab'][0].stoi['<unk>']
offset = len(self.vocabs['next_rules'])
out = scores.gather(
1,
align.view(-1, 1) + offset).view(-1).mul(
align.ne(align_unk).float()) # all where copy is not unk
tmp = scores.gather(1, target.view(-1, 1)).view(-1)
unk_mask = target.data.ne(self.tgt_unks[0])
for unk in self.tgt_unks:
unk_mask = unk_mask & target.data.ne(unk)
unk_mask_var = Variable(unk_mask, requires_grad=False)
inv_unk_mask_var = Variable(~unk_mask, requires_grad=False)
out = out + 1e-20 + tmp.mul(unk_mask_var.float()) + \
tmp.mul(align.eq(align_unk).float()).mul(inv_unk_mask_var.float()) # copy and target are unks
# Drop padding.
loss = -out.log().mul(target.ne(self.tgt_pad).float()).sum()
scores_data = scores.data.clone()
target_data = target.data.clone() #computeLoss populates this
scores_data = self.collapseCopyScores(
unbottle(scores_data, batch_size), batch)
scores_data = bottle(scores_data)
# Correct target copy token instead of <unk>
# tgt[i] = align[i] + len(tgt_vocab)
# for i such that tgt[i] == 0 and align[i] != 0
# when target is <unk> but can be copied, make sure we get the copy index right
correct_mask = inv_unk_mask_var.data * align.data.ne(align_unk)
correct_copy = (align.data + offset) * correct_mask.long()
target_data = (target_data * (~correct_mask).long()) + correct_copy
pred = scores_data.max(1)[1]
non_padding = target_data.ne(self.tgt_pad)
num_correct = pred.eq(target_data).masked_select(non_padding).sum()
return loss, non_padding.sum(), num_correct #, stats
def computeLoss(self, scores, batch):
"""
Args:
batch: the current batch.
target: the validate target to compare output with.
align: the align info.
"""
batch_size = batch['seq2seq'].size(0)
self.target = Variable(shiftLeft(batch['code'].cuda(),
self.tgt_padding_idx).view(-1),
requires_grad=False)
align = Variable(
shiftLeft(batch['code_in_src_nums'].cuda(),
self.vocabs['seq2seq'].stoi['<blank>']).view(-1),
requires_grad=False)
# All individual vocabs have the same unk index
align_unk = batch['seq2seq_vocab'][0].stoi['<unk>']
loss = self.criterion(scores, self.target, align, align_unk)
scores_data = scores.data.clone()
target_data = self.target.data.clone() #computeLoss populates this
if self.opt.copy_attn:
scores_data = self.collapseCopyScores(
unbottle(scores_data, batch_size), batch)
scores_data = bottle(scores_data)
# Correct target copy token instead of <unk>
# tgt[i] = align[i] + len(tgt_vocab)
# for i such that tgt[i] == 0 and align[i] != 0
# when target is <unk> but can be copied, make sure we get the copy index right
correct_mask = target_data.eq(
self.tgt_unk_idx) * align.data.ne(align_unk)
correct_copy = (align.data +
self.tgt_dict_size) * correct_mask.long()
target_data = (target_data *
(1 - correct_mask).long()) + correct_copy
pred = scores_data.max(1)[1]
non_padding = target_data.ne(self.tgt_padding_idx)
num_correct = pred.eq(target_data).masked_select(non_padding).sum()
return loss, non_padding.sum(), num_correct #, stats
def predict(self, enc_hidden, context, context_lengths, batch, beam_size,
max_code_length, generator, replace_unk, vis_params):
# This decoder does not have input feeding. Parent state replces that
decState = DecoderState(
enc_hidden, #encoder hidden
Variable(torch.zeros(1, 1, self.opt.decoder_rnn_size).cuda(),
requires_grad=False) # parent state
)
# Repeat everything beam_size times.
def rvar(a, beam_size):
return Variable(a.repeat(beam_size, 1, 1), volatile=True)
context = tuple(
rvar(context[i].data, beam_size) for i in range(0, len(context)))
context_lengths = tuple(context_lengths[i].repeat(beam_size, 1)
for i in range(0, len(context_lengths)))
decState.repeat_beam_size_times(beam_size)
# Use only one beam
beam = TreeBeam(beam_size, True, self.vocabs,
self.opt.decoder_rnn_size)
for count in range(
0, max_code_length
): # We will break when we have the required number of terminals
# to be consistent with seq2seq
if beam.done():
break
# Construct batch x beam_size nxt words.
# Get all the pending current beam words and arrange for forward.
# Uses the start symbol in the beginning
inp = beam.getCurrentState(
) # Should return a batch of the frontier
# Run one step., decState gets automatically updated
output, attn, copy_attn = self.forward(inp, context,
context_lengths, decState)
src_map = torch.zeros(0, 0)
if self.opt.var_names:
src_map = torch.cat((src_map, batch['concode_src_map_vars']),
1)
if self.opt.method_names:
src_map = torch.cat(
(src_map, batch['concode_src_map_methods']), 1)
scores = generator(bottle(output), bottle(copy_attn), src_map,
inp) #generator needs the non-terminals
out = generator.collapseCopyScores(
unbottle(scores.data.clone(), beam_size),
batch) # needs seq2seq from batch
out = out.log()
# beam x tgt_vocab
beam.advance(out[:, 0], attn.data[:, 0], output)
decState.beam_update(beam.getCurrentOrigin(), beam_size)
pred_score_total = 0
pred_words_total = 0
score, times, k = beam.getFinal(
) # times is the length of the prediction
hyp, att = beam.getHyp(times, k)
goldNl = []
if self.opt.var_names:
goldNl += batch['concode_var'][0] # because batch = 1
if self.opt.method_names:
goldNl += batch['concode_method'][0] # because batch = 1
goldCode = self.vocabs['code'].addStartOrEnd(batch['raw_code'][0])
predSent, copied_tokens, replaced_tokens = self.buildTargetTokens(
hyp, self.vocabs, goldNl, att, batch['concode_vocab'][0],
replace_unk)
predSent = ConcodeDecoder.rulesToCode(predSent)
pred_score_total += score
pred_words_total += len(predSent)
return Prediction(goldNl, goldCode, predSent, att)