Class: Transformers::Distilbert::Transformer

Inherits:
Torch::NN::Module
  • Object
show all
Defined in:
lib/transformers/models/distilbert/modeling_distilbert.rb

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ Transformer

Returns a new instance of Transformer.



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# File 'lib/transformers/models/distilbert/modeling_distilbert.rb', line 238

def initialize(config)
  super()
  @n_layers = config.n_layers
  @layer = Torch::NN::ModuleList.new(config.n_layers.times.map { TransformerBlock.new(config) })
  @gradient_checkpointing = false
end

Instance Method Details

#forward(x:, attn_mask: nil, head_mask: nil, output_attentions: false, output_hidden_states: false, return_dict: nil) ⇒ Object 



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# File 'lib/transformers/models/distilbert/modeling_distilbert.rb', line 245

def forward(
  x:,
  attn_mask: nil,
  head_mask: nil,
  output_attentions: false,
  output_hidden_states: false,
  return_dict: nil
)
  all_hidden_states = output_hidden_states ? [] : nil
  all_attentions = output_attentions ? [] : nil

  hidden_state = x
  @layer.each_with_index do |layer_module, i|
    if output_hidden_states
      all_hidden_states = all_hidden_states + [hidden_state]
    end

    if @gradient_checkpointing && training
      layer_outputs =
        _gradient_checkpointing_func(
          layer_module.__call__,
          hidden_state,
          attn_mask,
          head_mask[i],
          output_attentions,
        )
    else
      layer_outputs =
        layer_module.(
          x: hidden_state,
          attn_mask: attn_mask,
          head_mask: head_mask[i],
          output_attentions: output_attentions
        )
    end

    hidden_state = layer_outputs[-1]

    if output_attentions
      if layer_outputs.length != 2
        raise ArgumentError, "The length of the layer_outputs should be 2, but it is #{layer_outputs.length}"
      end

      attentions = layer_outputs[0]
      all_attentions = all_attentions + [attentions]
    else
      if layer_outputs.length != 1
        raise ArgumentError, "The length of the layer_outputs should be 1, but it is #{layer_outputs.length}"
      end
    end
  end

  # Add last layer
  if output_hidden_states
    all_hidden_states = all_hidden_states + [hidden_state]
  end

  if !return_dict
    raise Todo
  end
  BaseModelOutput.new(
    last_hidden_state: hidden_state, hidden_states: all_hidden_states, attentions: all_attentions
  )
end