# coding=utf-8
# Copyright 2019-present, the HuggingFace Inc. team, The Google AI Language Team and Facebook, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import Callable, Optional, Tuple
import numpy as np
import flax.linen as nn
import jax
import jax.numpy as jnp
from flax.core.frozen_dict import FrozenDict
from jax import lax
from ...file_utils import add_start_docstrings, add_start_docstrings_to_model_forward
from ...modeling_flax_outputs import (
FlaxBaseModelOutput,
FlaxMaskedLMOutput,
FlaxMultipleChoiceModelOutput,
FlaxQuestionAnsweringModelOutput,
FlaxSequenceClassifierOutput,
FlaxTokenClassifierOutput,
)
from ...modeling_flax_utils import ACT2FN, FlaxPreTrainedModel, append_call_sample_docstring, overwrite_call_docstring
from ...utils import logging
from .configuration_distilbert import DistilBertConfig
logger = logging.get_logger(__name__)
_CHECKPOINT_FOR_DOC = "distilbert-base-uncased"
_CONFIG_FOR_DOC = "DistilBertConfig"
_TOKENIZER_FOR_DOC = "DistilBertTokenizer"
FLAX_DISTILBERT_START_DOCSTRING = r"""
This model inherits from :class:`~transformers.FlaxPreTrainedModel`. Check the superclass documentation for the
generic methods the library implements for all its model (such as downloading, saving and converting weights from
PyTorch models)
This model is also a Flax Linen `flax.linen.Module
<https://flax.readthedocs.io/en/latest/flax.linen.html#module>`__ subclass. Use it as a regular Flax linen Module
and refer to the Flax documentation for all matter related to general usage and behavior.
Finally, this model supports inherent JAX features such as:
- `Just-In-Time (JIT) compilation <https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit>`__
- `Automatic Differentiation <https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation>`__
- `Vectorization <https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap>`__
- `Parallelization <https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap>`__
Parameters:
config (:class:`~transformers.DistilBertConfig`): Model configuration class with all the parameters of the model.
Initializing with a config file does not load the weights associated with the model, only the
configuration. Check out the :meth:`~transformers.PreTrainedModel.from_pretrained` method to load the model
weights.
"""
DISTILBERT_INPUTS_DOCSTRING = r"""
Args:
input_ids (:obj:`numpy.ndarray` of shape :obj:`({0})`):
Indices of input sequence tokens in the vocabulary.
Indices can be obtained using :class:`~transformers.BertTokenizer`. See
:meth:`transformers.PreTrainedTokenizer.encode` and :func:`transformers.PreTrainedTokenizer.__call__` for
details.
`What are input IDs? <../glossary.html#input-ids>`__
attention_mask (:obj:`numpy.ndarray` of shape :obj:`({0})`, `optional`):
Mask to avoid performing attention on padding token indices. Mask values selected in ``[0, 1]``:
- 1 for tokens that are **not masked**,
- 0 for tokens that are **masked**.
`What are attention masks? <../glossary.html#attention-mask>`__
output_attentions (:obj:`bool`, `optional`):
Whether or not to return the attentions tensors of all attention layers. See ``attentions`` under returned
tensors for more detail.
output_hidden_states (:obj:`bool`, `optional`):
Whether or not to return the hidden states of all layers. See ``hidden_states`` under returned tensors for
more detail.
return_dict (:obj:`bool`, `optional`):
Whether or not to return a :class:`~transformers.file_utils.ModelOutput` instead of a plain tuple.
"""
def get_angles(pos, i, d_model):
angle_rates = 1 / np.power(10000, (2 * (i // 2)) / np.float32(d_model))
return pos * angle_rates
def positional_encoding(position, d_model, dtype):
# create the sinusoidal pattern for the positional encoding
angle_rads = get_angles(np.arange(position)[:, np.newaxis], np.arange(d_model)[np.newaxis, :], d_model)
# apply sin to even indices in the array; 2i
angle_rads[:, 0::2] = np.sin(angle_rads[:, 0::2])
# apply cos to odd indices in the array; 2i+1
angle_rads[:, 1::2] = np.cos(angle_rads[:, 1::2])
pos_encoding = angle_rads[np.newaxis, ...]
# cast to dtype
return jnp.array(pos_encoding, dtype=dtype)
class FlaxEmbeddings(nn.Module):
"""Construct the embeddings from word, position and token_type embeddings."""
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.word_embeddings = nn.Embed(
self.config.vocab_size,
self.config.dim,
embedding_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
dtype=self.dtype,
)
if not self.config.sinusoidal_pos_embds:
self.position_embeddings = nn.Embed(
self.config.max_position_embeddings,
self.config.dim,
embedding_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
dtype=self.dtype,
)
else:
self.pos_encoding = positional_encoding(self.config.max_position_embeddings, self.config.dim, self.dtype)
self.LayerNorm = nn.LayerNorm(epsilon=1e-12, dtype=self.dtype)
self.dropout = nn.Dropout(rate=self.config.dropout)
def __call__(self, input_ids, deterministic: bool = True):
# Embed
batch_size, seq_length = input_ids.shape
inputs_embeds = self.word_embeddings(input_ids.astype("i4"))
if not self.config.sinusoidal_pos_embds:
position_ids = jnp.arange(seq_length).astype("i4")
position_ids = jnp.broadcast_to(position_ids, shape=(batch_size, seq_length))
position_embeds = self.position_embeddings(position_ids.astype("i4"))
else:
position_embeds = self.pos_encoding[:, :seq_length, :]
# Sum all embeddings
hidden_states = inputs_embeds + position_embeds
# Layer Norm
hidden_states = self.LayerNorm(hidden_states)
hidden_states = self.dropout(hidden_states, deterministic=deterministic)
return hidden_states
class FlaxMultiHeadSelfAttention(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.n_heads = self.config.n_heads
self.dim = self.config.dim
self.dropout = nn.Dropout(rate=self.config.attention_dropout)
assert self.dim % self.n_heads == 0, f"Hidden size {self.dim} not dividable by number of heads {self.n_heads}"
self.q_lin = nn.Dense(
self.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.k_lin = nn.Dense(
self.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.v_lin = nn.Dense(
self.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.out_lin = nn.Dense(
self.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
def __call__(
self,
query,
key,
value,
mask,
deterministic: bool = True,
output_attentions: bool = False,
):
bs, q_len, dim = query.shape
k_len = key.shape[1]
# assert dim == self.dim, f'Dimensions do not match: {dim} input vs {self.dim} configured'
# assert key.size() == value.size()
dim_per_head = self.dim // self.n_heads
mask_reshp = (bs, 1, 1, k_len)
def shape(x):
"""separate heads"""
return x.reshape(bs, -1, self.n_heads, dim_per_head).transpose(0, 2, 1, 3)
def unshape(x):
"""group heads"""
return x.transpose(0, 2, 1, 3).reshape(bs, -1, self.n_heads * dim_per_head)
q = shape(self.q_lin(query)) # (bs, n_heads, q_len, dim_per_head)
k = shape(self.k_lin(key)) # (bs, n_heads, k_len, dim_per_head)
v = shape(self.v_lin(value)) # (bs, n_heads, k_len, dim_per_head)
q = q / math.sqrt(dim_per_head) # (bs, n_heads, q_len, dim_per_head)
scores = jnp.matmul(q, k.transpose(0, 1, 3, 2)) # (bs, n_heads, q_len, k_len)
mask = jnp.reshape(mask, mask_reshp)
mask = mask.astype(scores.dtype)
scores = scores - 1e30 * (1.0 - mask)
weights = nn.softmax(scores, axis=-1) # (bs, n_heads, q_len, k_len)
weights = self.dropout(weights, deterministic=deterministic)
context = jnp.matmul(weights, v) # (bs, n_heads, q_len, dim_per_head)
context = unshape(context) # (bs, q_len, dim)
context = self.out_lin(context) # (bs, q_len, dim)
if output_attentions:
return (context, weights)
else:
return (context,)
class FlaxFFN(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.dropout = nn.Dropout(rate=self.config.dropout)
self.chunk_size_feed_forward = self.config.chunk_size_feed_forward
self.seq_len_dim = 1
self.lin1 = nn.Dense(
self.config.hidden_dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.lin2 = nn.Dense(
self.config.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
assert self.config.activation in [
"relu",
"gelu",
], f"activation ({self.config.activation}) must be in ['relu', 'gelu']"
self.activation = ACT2FN[self.config.activation]
def __call__(self, hidden_states, deterministic: bool = True):
hidden_states = self.lin1(hidden_states)
hidden_states = self.activation(hidden_states)
hidden_states = self.lin2(hidden_states)
hidden_states = self.dropout(hidden_states, deterministic=deterministic)
return hidden_states
class FlaxTransformerBlock(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
assert (
self.config.dim % self.config.n_heads == 0
), f"Hidden size {self.config.dim} not dividable by number of heads {self.config.n_heads}"
self.attention = FlaxMultiHeadSelfAttention(self.config, dtype=self.dtype)
self.sa_layer_norm = nn.LayerNorm(epsilon=1e-12)
self.ffn = FlaxFFN(self.config, dtype=self.dtype)
self.output_layer_norm = nn.LayerNorm(epsilon=1e-12)
def __call__(
self,
hidden_states,
attn_mask,
output_attentions: bool = False,
deterministic: bool = True,
):
# Self-Attention
sa_output = self.attention(
query=hidden_states,
key=hidden_states,
value=hidden_states,
mask=attn_mask,
output_attentions=output_attentions,
deterministic=deterministic,
)
if output_attentions:
sa_output, sa_weights = sa_output
else:
assert type(sa_output) == tuple
sa_output = sa_output[0]
sa_output = self.sa_layer_norm(sa_output + hidden_states)
# Feed Forward Network
ffn_output = self.ffn(sa_output, deterministic=deterministic)
ffn_output = self.output_layer_norm(ffn_output + sa_output)
output = (ffn_output,)
if output_attentions:
output = (sa_weights,) + output
return output
class FlaxTransformer(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.layers = [
FlaxTransformerBlock(self.config, name=str(i), dtype=self.dtype) for i in range(self.config.n_layers)
]
def __call__(
self,
hidden_states,
attention_mask,
output_attentions: bool = False,
output_hidden_states: bool = False,
deterministic: bool = True,
return_dict: bool = False,
):
all_hidden_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
for layer_module in self.layers:
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
layer_outputs = layer_module(
hidden_states=hidden_states,
attn_mask=attention_mask,
output_attentions=output_attentions,
deterministic=deterministic,
)
hidden_states = layer_outputs[-1]
if output_attentions:
assert len(layer_outputs) == 2
attentions = layer_outputs[0]
all_attentions = all_attentions + (attentions,)
else:
assert len(layer_outputs) == 1
# Add last layer
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if not return_dict:
return tuple(v for v in [hidden_states, all_attentions, all_hidden_states] if v is not None)
return FlaxBaseModelOutput(
last_hidden_state=hidden_states, hidden_states=all_hidden_states, attentions=all_attentions
)
class FlaxTransformerEncoder(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.layer = FlaxTransformer(self.config, dtype=self.dtype)
def __call__(
self,
hidden_states,
attention_mask,
output_attentions: bool = False,
output_hidden_states: bool = False,
deterministic: bool = True,
return_dict: bool = False,
):
return self.layer(
hidden_states=hidden_states,
attention_mask=attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
deterministic=deterministic,
return_dict=return_dict,
)
class FlaxDistilBertLMDecoder(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
bias_init: Callable[..., np.ndarray] = jax.nn.initializers.zeros
def setup(self):
self.bias = self.param("bias", self.bias_init, (self.config.vocab_size,))
def __call__(self, inputs, kernel):
y = lax.dot_general(inputs, kernel, (((inputs.ndim - 1,), (0,)), ((), ())))
y = y + self.bias
return y
class FlaxDistilBertPreTrainedModel(FlaxPreTrainedModel):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = DistilBertConfig
base_model_prefix = "distilbert"
module_class: nn.Module = None
def __init__(
self,
config: DistilBertConfig,
input_shape: Tuple = (1, 1),
seed: int = 0,
dtype: jnp.dtype = jnp.float32,
**kwargs
):
module = self.module_class(config=config, dtype=dtype, **kwargs)
super().__init__(config, module, input_shape=input_shape, seed=seed, dtype=dtype)
def init_weights(self, rng: jax.random.PRNGKey, input_shape: Tuple) -> FrozenDict:
# init input tensors
input_ids = jnp.zeros(input_shape, dtype="i4")
attention_mask = jnp.ones_like(input_ids)
params_rng, dropout_rng = jax.random.split(rng)
rngs = {"params": params_rng, "dropout": dropout_rng}
return self.module.init(rngs, input_ids, attention_mask, return_dict=False)["params"]
@add_start_docstrings_to_model_forward(DISTILBERT_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
def __call__(
self,
input_ids,
attention_mask=None,
head_mask=None,
params: dict = None,
dropout_rng: jax.random.PRNGKey = None,
train: bool = False,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
):
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.return_dict
if attention_mask is None:
attention_mask = jnp.ones_like(input_ids)
# Handle any PRNG if needed
rngs = {}
if dropout_rng is not None:
rngs["dropout"] = dropout_rng
return self.module.apply(
{"params": params or self.params},
jnp.array(input_ids, dtype="i4"),
jnp.array(attention_mask, dtype="i4"),
not train,
output_attentions,
output_hidden_states,
return_dict,
rngs=rngs,
)
class FlaxDistilBertModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.embeddings = FlaxEmbeddings(self.config, dtype=self.dtype)
self.transformer = FlaxTransformerEncoder(self.config, dtype=self.dtype)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.return_dict
input_embeds = self.embeddings(input_ids, deterministic=deterministic)
return self.transformer(
hidden_states=input_embeds,
attention_mask=attention_mask,
deterministic=deterministic,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
[docs]@add_start_docstrings(
"The bare DistilBert Model transformer outputting raw hidden-states without any specific head on top.",
FLAX_DISTILBERT_START_DOCSTRING,
)
class FlaxDistilBertModel(FlaxDistilBertPreTrainedModel):
module_class = FlaxDistilBertModule
append_call_sample_docstring(FlaxDistilBertModel, _TOKENIZER_FOR_DOC, _CHECKPOINT_FOR_DOC, None, _CONFIG_FOR_DOC)
class FlaxDistilBertForMaskedLMModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32 # the dtype of the computation
def setup(self):
self.distilbert = FlaxDistilBertModule(self.config, dtype=self.dtype)
self.vocab_transform = nn.Dense(
self.config.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.vocab_layer_norm = nn.LayerNorm(epsilon=1e-12, dtype=self.dtype)
if self.config.tie_word_embeddings:
self.vocab_projector = FlaxDistilBertLMDecoder(
self.config,
dtype=self.dtype,
)
else:
self.vocab_projector = nn.Dense(
self.config.vocab_size,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
dlbrt_output = self.distilbert(
input_ids=input_ids,
attention_mask=attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
deterministic=deterministic,
return_dict=return_dict,
)
hidden_states = dlbrt_output[0]
prediction_logits = self.vocab_transform(hidden_states)
prediction_logits = ACT2FN["gelu"](prediction_logits)
prediction_logits = self.vocab_layer_norm(prediction_logits)
if self.config.tie_word_embeddings:
shared_embedding = self.distilbert.variables["params"]["embeddings"]["word_embeddings"]["embedding"]
prediction_logits = self.vocab_projector(prediction_logits, shared_embedding.T)
else:
prediction_logits = self.vocab_projector(prediction_logits)
if not return_dict:
output = (prediction_logits,) + dlbrt_output[1:]
return output
return FlaxMaskedLMOutput(
logits=prediction_logits,
hidden_states=dlbrt_output.hidden_states,
attentions=dlbrt_output.attentions,
)
append_call_sample_docstring(
FlaxDistilBertForMaskedLM, _TOKENIZER_FOR_DOC, _CHECKPOINT_FOR_DOC, FlaxMaskedLMOutput, _CONFIG_FOR_DOC
)
class FlaxDistilBertForSequenceClassificationModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32
def setup(self):
self.distilbert = FlaxDistilBertModule(config=self.config, dtype=self.dtype)
self.pre_classifier = nn.Dense(
self.config.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.dropout = nn.Dropout(rate=self.config.seq_classif_dropout)
self.classifier = nn.Dense(
self.config.num_labels,
dtype=self.dtype,
)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# Model
distilbert_output = self.distilbert(
input_ids,
attention_mask,
deterministic=deterministic,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_state = distilbert_output[0] # (bs, seq_len, dim)
pooled_output = hidden_state[:, 0] # (bs, dim)
pooled_output = self.pre_classifier(pooled_output) # (bs, dim)
pooled_output = ACT2FN["relu"](pooled_output)
pooled_output = self.dropout(pooled_output, deterministic=deterministic)
logits = self.classifier(pooled_output) # (bs, dim)
if not return_dict:
return (logits,) + distilbert_output[1:]
return FlaxSequenceClassifierOutput(
logits=logits,
hidden_states=distilbert_output.hidden_states,
attentions=distilbert_output.attentions,
)
[docs]@add_start_docstrings(
"""
DistilBert Model transformer with a sequence classification/regression head on top (a linear layer on top of the
pooled output) e.g. for GLUE tasks.
""",
FLAX_DISTILBERT_START_DOCSTRING,
)
class FlaxDistilBertForSequenceClassification(FlaxDistilBertPreTrainedModel):
module_class = FlaxDistilBertForSequenceClassificationModule
append_call_sample_docstring(
FlaxDistilBertForSequenceClassification,
_TOKENIZER_FOR_DOC,
_CHECKPOINT_FOR_DOC,
FlaxSequenceClassifierOutput,
_CONFIG_FOR_DOC,
)
class FlaxDistilBertForMultipleChoiceModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32
def setup(self):
self.distilbert = FlaxDistilBertModule(config=self.config, dtype=self.dtype)
self.pre_classifier = nn.Dense(
self.config.dim,
dtype=self.dtype,
kernel_init=jax.nn.initializers.normal(stddev=self.config.initializer_range),
)
self.dropout = nn.Dropout(rate=self.config.seq_classif_dropout)
self.classifier = nn.Dense(
1,
dtype=self.dtype,
)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
num_choices = input_ids.shape[1]
input_ids = input_ids.reshape(-1, input_ids.shape[-1]) if input_ids is not None else None
attention_mask = attention_mask.reshape(-1, attention_mask.shape[-1]) if attention_mask is not None else None
# Model
outputs = self.distilbert(
input_ids,
attention_mask,
deterministic=deterministic,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_state = outputs[0]
pooled_output = hidden_state[:, 0]
pooled_output = self.pre_classifier(pooled_output)
pooled_output = ACT2FN["relu"](pooled_output)
pooled_output = self.dropout(pooled_output, deterministic=deterministic)
logits = self.classifier(pooled_output)
reshaped_logits = logits.reshape(-1, num_choices)
if not return_dict:
return (reshaped_logits,) + outputs[2:]
return FlaxMultipleChoiceModelOutput(
logits=reshaped_logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
overwrite_call_docstring(
FlaxDistilBertForMultipleChoice, DISTILBERT_INPUTS_DOCSTRING.format("batch_size, num_choices, sequence_length")
)
append_call_sample_docstring(
FlaxDistilBertForMultipleChoice,
_TOKENIZER_FOR_DOC,
_CHECKPOINT_FOR_DOC,
FlaxMultipleChoiceModelOutput,
_CONFIG_FOR_DOC,
)
class FlaxDistilBertForTokenClassificationModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32
def setup(self):
self.distilbert = FlaxDistilBertModule(config=self.config, dtype=self.dtype)
self.dropout = nn.Dropout(rate=self.config.dropout)
self.classifier = nn.Dense(self.config.num_labels, dtype=self.dtype)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# Model
outputs = self.distilbert(
input_ids,
attention_mask,
deterministic=deterministic,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = outputs[0]
hidden_states = self.dropout(hidden_states, deterministic=deterministic)
logits = self.classifier(hidden_states)
if not return_dict:
return (logits,) + outputs[1:]
return FlaxTokenClassifierOutput(
logits=logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
[docs]@add_start_docstrings(
"""
DistilBert Model with a token classification head on top (a linear layer on top of the hidden-states output) e.g.
for Named-Entity-Recognition (NER) tasks.
""",
FLAX_DISTILBERT_START_DOCSTRING,
)
class FlaxDistilBertForTokenClassification(FlaxDistilBertPreTrainedModel):
module_class = FlaxDistilBertForTokenClassificationModule
append_call_sample_docstring(
FlaxDistilBertForTokenClassification,
_TOKENIZER_FOR_DOC,
_CHECKPOINT_FOR_DOC,
FlaxTokenClassifierOutput,
_CONFIG_FOR_DOC,
)
class FlaxDistilBertForQuestionAnsweringModule(nn.Module):
config: DistilBertConfig
dtype: jnp.dtype = jnp.float32
def setup(self):
self.distilbert = FlaxDistilBertModule(config=self.config, dtype=self.dtype)
self.qa_outputs = nn.Dense(self.config.num_labels, dtype=self.dtype)
assert self.config.num_labels == 2
self.dropout = nn.Dropout(rate=self.config.qa_dropout)
def __call__(
self,
input_ids,
attention_mask,
deterministic: bool = True,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# Model
distilbert_output = self.distilbert(
input_ids,
attention_mask,
deterministic=deterministic,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = distilbert_output[0]
hidden_states = self.dropout(hidden_states, deterministic=deterministic)
logits = self.qa_outputs(hidden_states)
start_logits, end_logits = logits.split(self.config.num_labels, axis=-1)
start_logits = start_logits.squeeze(-1)
end_logits = end_logits.squeeze(-1)
if not return_dict:
return (start_logits, end_logits) + distilbert_output[1:]
return FlaxQuestionAnsweringModelOutput(
start_logits=start_logits,
end_logits=end_logits,
hidden_states=distilbert_output.hidden_states,
attentions=distilbert_output.attentions,
)
[docs]@add_start_docstrings(
"""
DistilBert Model with a span classification head on top for extractive question-answering tasks like SQuAD (a
linear layers on top of the hidden-states output to compute `span start logits` and `span end logits`).
""",
FLAX_DISTILBERT_START_DOCSTRING,
)
class FlaxDistilBertForQuestionAnswering(FlaxDistilBertPreTrainedModel):
module_class = FlaxDistilBertForQuestionAnsweringModule
append_call_sample_docstring(
FlaxDistilBertForQuestionAnswering,
_TOKENIZER_FOR_DOC,
_CHECKPOINT_FOR_DOC,
FlaxQuestionAnsweringModelOutput,
_CONFIG_FOR_DOC,
)