Class: Boxcars::Train Abstract

Inherits:
EngineBoxcar show all
Defined in:
lib/boxcars/train.rb

Overview

This class is abstract.

Direct Known Subclasses

XMLTrain, ZeroShot

Instance Attribute Summary collapse

Attributes inherited from EngineBoxcar

#engine, #prompt, #stop, #top_k

Attributes inherited from Boxcar

#description, #name, #parameters, #return_direct

Instance Method Summary collapse

Methods inherited from EngineBoxcar

#apply, #check_output_keys, #extract_code, #generate, #input_key, #output_key, #predict, #prediction_additional, #prediction_input, #prediction_variables

Methods inherited from Boxcar

#apply, assi, #conduct, hist, #load, #run, #save, #schema, syst, user, #validate_inputs, #validate_outputs

Constructor Details

#initialize(boxcars:, prompt:, engine: nil, **kwargs) ⇒ Train

This method is abstract.

A Train will use a engine to run a series of boxcars.

Parameters:

  • boxcars (Array<Boxcars::Boxcar>) —

    The boxcars to run.

  • prompt (Boxcars::Prompt) —

    The prompt to use.

  • engine (Boxcars::Engine) (defaults to: nil) —

    The engine to use for this train.

  • kwargs (Hash) —

    Additional arguments including: name, description, top_k, return_direct, and stop



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# File 'lib/boxcars/train.rb', line 16

def initialize(boxcars:, prompt:, engine: nil, **kwargs)
  @boxcars = boxcars
  @name_to_boxcar_map = boxcars.to_h { |boxcar| [boxcar.name, boxcar] }
  @return_values = [:output]
  @return_intermediate_steps = kwargs.fetch(:return_intermediate_steps, true)
  kwargs.delete(:return_intermediate_steps)
  @max_iterations = kwargs.delete(:max_iterations) || 25
  @early_stopping_method = kwargs.delete(:early_stopping_method) || "force"
  init_prefixes
  kwargs[:stop] = ["\n#{observation_prefix}"] unless kwargs.key?(:stop)

  super(prompt: prompt, engine: engine, **kwargs)
end

Instance Attribute Details

#answer_prefix ⇒ Object (readonly)

Returns the value of attribute answer_prefix.



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# File 'lib/boxcars/train.rb', line 6

def answer_prefix
  @answer_prefix
end

#boxcars ⇒ Object (readonly)

Returns the value of attribute boxcars.



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# File 'lib/boxcars/train.rb', line 6

def boxcars
  @boxcars
end

#early_stopping_method ⇒ Object (readonly)

Returns the value of attribute early_stopping_method.



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# File 'lib/boxcars/train.rb', line 6

def early_stopping_method
  @early_stopping_method
end

#engine_prefix ⇒ Object (readonly)

Returns the value of attribute engine_prefix.



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# File 'lib/boxcars/train.rb', line 6

def engine_prefix
  @engine_prefix
end

#final_answer_prefix ⇒ Object (readonly)

Returns the value of attribute final_answer_prefix.



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# File 'lib/boxcars/train.rb', line 6

def final_answer_prefix
  @final_answer_prefix
end

#max_iterations ⇒ Object (readonly)

Returns the value of attribute max_iterations.



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# File 'lib/boxcars/train.rb', line 6

def max_iterations
  @max_iterations
end

#name_to_boxcar_map ⇒ Object (readonly)

Returns the value of attribute name_to_boxcar_map.



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# File 'lib/boxcars/train.rb', line 6

def name_to_boxcar_map
  @name_to_boxcar_map
end

#observation_prefix ⇒ Object (readonly)

Returns the value of attribute observation_prefix.



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# File 'lib/boxcars/train.rb', line 6

def observation_prefix
  @observation_prefix
end

#question_prefix ⇒ Object (readonly)

Returns the value of attribute question_prefix.



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# File 'lib/boxcars/train.rb', line 6

def question_prefix
  @question_prefix
end

#return_intermediate_steps ⇒ Object (readonly)

Returns the value of attribute return_intermediate_steps.



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# File 'lib/boxcars/train.rb', line 6

def return_intermediate_steps
  @return_intermediate_steps
end

#return_values ⇒ Object (readonly)

Returns the value of attribute return_values.



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# File 'lib/boxcars/train.rb', line 6

def return_values
  @return_values
end

#thought_prefix ⇒ Object (readonly)

Returns the value of attribute thought_prefix.



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# File 'lib/boxcars/train.rb', line 6

def thought_prefix
  @thought_prefix
end

#using_xml ⇒ Object (readonly)

Returns the value of attribute using_xml.



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# File 'lib/boxcars/train.rb', line 6

def using_xml
  @using_xml
end

Instance Method Details

#boxcar_descriptions ⇒ Object 



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# File 'lib/boxcars/train.rb', line 262

def boxcar_descriptions
  @boxcar_descriptions ||= boxcars.map { |boxcar| "#{boxcar.name}: #{boxcar.description}" }.join("\n")
end

#boxcar_names ⇒ Object 



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# File 'lib/boxcars/train.rb', line 258

def boxcar_names
  @boxcar_names ||= boxcars.map(&:name).join(', ')
end

#call(inputs:) ⇒ Hash

execute the train train

Parameters:

  • inputs (Hash) —

    The inputs.

Returns:

  • (Hash) —

    The output.



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# File 'lib/boxcars/train.rb', line 202

def call(inputs:)
  prepare_for_new_call
  intermediate_steps = []
  iterations = 0
  while should_continue?(iterations)
    output = plan(intermediate_steps, **inputs)
    return pre_return(output, intermediate_steps) if output.is_a?(TrainFinish)

    if (boxcar = name_to_boxcar_map[output.boxcar])
      begin
        observation = Observation.ok(get_boxcar_result(boxcar, output.boxcar_input))
        return_direct = boxcar.return_direct
      rescue Boxcars::ConfigurationError, Boxcars::SecurityError => e
        raise e
      rescue StandardError => e
        Boxcars.error "Error in #{boxcar.name} train#call: #{e}\nbt:#{caller[0..5].join("\n   ")}", :red
        observation = Observation.err("Error - #{e}, correct and try again.")
      end
    elsif output.boxcar == :error
      observation = output.log
      return_direct = false
    else
      observation = Observation.err("Error - #{output.boxcar} is not a valid action, try again.")
      return_direct = false
    end
    Boxcars.debug "Observation: #{observation}", :green
    intermediate_steps.append([output, observation])
    if return_direct
      output = TrainFinish.new({ return_values[0] => observation }, "")
      return pre_return(output, intermediate_steps)
    end
    iterations += 1
  end
  output = return_stopped_response(early_stopping_method, intermediate_steps, **inputs)
  pre_return(output, intermediate_steps)
end

#construct_scratchpad(intermediate_steps) ⇒ String

build the scratchpad for the engine

Parameters:

  • intermediate_steps (Array) —

    The intermediate steps to build the scratchpad from.

Returns:

  • (String) —

    The scratchpad.



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# File 'lib/boxcars/train.rb', line 47

def construct_scratchpad(intermediate_steps)
  thoughts = engine_prefix.to_s
  intermediate_steps.each do |action, observation|
    thoughts += action.is_a?(String) ? action : " #{action.log}"
    thoughts += "\n#{observation_text(observation)}\n#{engine_prefix}"
  end
  thoughts
end

#extract_boxcar_and_input(text) ⇒ Object

Callback to process the action/action input of a train.

Parameters:

  • text (String) —

    The text to extract from.



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# File 'lib/boxcars/train.rb', line 40

def extract_boxcar_and_input(text)
  Result.new(status: :ok, answer: text, explanation: engine_output)
end

#finish_boxcar_name ⇒ Object

Name of the boxcar to use to finish the chain



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# File 'lib/boxcars/train.rb', line 95

def finish_boxcar_name
  "Final Answer"
end

#get_boxcar_result(boxcar, boxcar_input) ⇒ Object 



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# File 'lib/boxcars/train.rb', line 187

def get_boxcar_result(boxcar, boxcar_input)
  boxcar_result = boxcar.run(boxcar_input)
  return boxcar_result unless using_xml

  if boxcar_result.is_a?(Result)
    boxcar_result.answer = boxcar_result.answer.encode(xml: :text) if boxcar_result.answer.is_a?(String)
  elsif boxcar_result.is_a?(String)
    boxcar_result = boxcar_result.encode(xml: :text)
  end
  boxcar_result
end

#get_next_action(full_inputs) ⇒ Boxcars::Action

determine the next action

Parameters:

  • full_inputs (Hash) —

    The inputs to the engine.

Returns:

  • (Boxcars::Action) —

    The next action.



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# File 'lib/boxcars/train.rb', line 59

def get_next_action(full_inputs)
  full_output = ""
  parsed_output = nil
  loop do
    full_inputs[:agent_scratchpad] += full_output
    output = predict(**full_inputs)
    full_output += output.to_s
    parsed_output = extract_boxcar_and_input(full_output)
    break unless parsed_output.nil?
  end
  if parsed_output.is_a?(Result)
    TrainAction.from_result(boxcar: "Final Answer", result: parsed_output, log: full_output)
  # elsif parsed_output[0] == "Error"
  else
    TrainAction.new(boxcar: parsed_output[0], boxcar_input: parsed_output[1], log: full_output)
  end
end

#init_prefixes ⇒ Object 



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# File 'lib/boxcars/train.rb', line 30

def init_prefixes
  @thought_prefix ||= "Thought: "
  @observation_prefix ||= "Observation: "
  @final_answer_prefix ||= "Final Answer: "
  @answer_prefix ||= "Answer:"
  @question_prefix ||= "Question: "
end

#input_keys ⇒ Array<Symbol>

the input keys

Returns:

  • (Array<Symbol>) —

    The input keys.



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# File 'lib/boxcars/train.rb', line 101

def input_keys
  prompt.input_variables - [:agent_scratchpad]
end

#key_and_value_text(key, value) ⇒ Object 



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# File 'lib/boxcars/train.rb', line 239

def key_and_value_text(key, value)
  value = value.to_s
  if key =~ /^<(?<tag_name>[[:word:]]+)>$/
    # we need a close tag too
    "#{key}#{value}</#{Regexp.last_match[:tag_name]}>"
  else
    "#{key}#{value}"
  end
end

#next_actions ⇒ Object 



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# File 'lib/boxcars/train.rb', line 266

def next_actions
  if wants_next_actions
    "Next Actions: Up to 3 logical suggested next questions for the user to ask after getting this answer.\n"
  else
    ""
  end
end

#observation_text(observation) ⇒ Object

this is for the scratchpad



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# File 'lib/boxcars/train.rb', line 250

def observation_text(observation)
  key_and_value_text(observation_prefix, observation)
end

#output_keys ⇒ Object

the output keys



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# File 'lib/boxcars/train.rb', line 106

def output_keys
  return return_values + [:intermediate_steps] if return_intermediate_steps

  return_values
end

#plan(intermediate_steps, **kwargs) ⇒ Boxcars::Action

Given input, decided what to do.

Parameters:

  • intermediate_steps (Array<Hash>) —

    The intermediate steps taken so far along with observations.

  • kwargs (Hash) —

    User inputs.

Returns:

  • (Boxcars::Action) —

    Action specifying what boxcar to use.



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# File 'lib/boxcars/train.rb', line 81

def plan(intermediate_steps, **kwargs)
  thoughts = construct_scratchpad(intermediate_steps)
  full_inputs = prediction_additional(kwargs).merge(kwargs).merge(agent_scratchpad: thoughts)
  action = get_next_action(full_inputs)
  return TrainFinish.new({ output: action.boxcar_input }, log: action.log) if action.boxcar == finish_boxcar_name

  action
end

#pre_return(output, intermediate_steps) ⇒ Hash

handler before returning

Parameters:

  • output (Boxcars::TrainFinish) —

    The output.

  • intermediate_steps (Array<Hash>) —

    The intermediate steps.

Returns:

  • (Hash) —

    The final output.



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# File 'lib/boxcars/train.rb', line 125

def pre_return(output, intermediate_steps)
  Boxcars.debug output.log, :yellow, style: :bold
  final_output = output.return_values
  final_output[:intermediate_steps] = intermediate_steps if return_intermediate_steps
  final_output
end

#prepare_for_new_call ⇒ Object

Prepare the agent for new call, if needed



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# File 'lib/boxcars/train.rb', line 91

def prepare_for_new_call
end

#question_text(question) ⇒ Object 



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# File 'lib/boxcars/train.rb', line 254

def question_text(question)
  key_and_value_text(question_prefix, question)
end

#return_stopped_response(early_stopping_method, intermediate_steps, **kwargs) ⇒ Boxcars::Action

get the stopped response

Parameters:

  • early_stopping_method (String) —

    The early stopping method.

  • intermediate_steps (Array) —

    The intermediate steps.

  • kwargs (Hash) —

    extra keword arguments.

Returns:

  • (Boxcars::Action) —

    The action to take.



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# File 'lib/boxcars/train.rb', line 156

def return_stopped_response(early_stopping_method, intermediate_steps, **kwargs)
  case early_stopping_method
  when "force"
    TrainFinish.new({ output: "Agent stopped due to max iterations." }, "")
  when "generate"
    thoughts = ""
    intermediate_steps.each do |action, observation|
      thoughts += action.log
      thoughts += "\n#{observation_text(observation)}\n#{engine_prefix}"
    end
    thoughts += "\n\nI now need to return a final answer based on the previous steps:"
    new_inputs = { agent_scratchpad: thoughts, stop: _stop }
    full_inputs = kwargs.merge(new_inputs)
    full_output = predict(**full_inputs)
    parsed_output = extract_boxcar_and_input(full_output)
    if parsed_output.nil?
      TrainFinish.new({ output: full_output }, full_output)
    else
      boxcar, boxcar_input = parsed_output
      Boxcars.debug "Got boxcar #{boxcar} and input #{boxcar_input}"
      if boxcar == finish_boxcar_name
        TrainFinish.new({ output: boxcar_input }, full_output)
      else
        TrainFinish.new({ output: full_output }, full_output)
      end
    end
  else
    raise "early_stopping_method should be one of `force` or `generate`, got #{early_stopping_method}"
  end
end

#should_continue?(iterations) ⇒ Boolean

should we continue to run?

Parameters:

  • iterations (Integer) —

    The number of iterations.

Returns:

  • (Boolean) —

    Whether to continue.



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# File 'lib/boxcars/train.rb', line 115

def should_continue?(iterations)
  return true if max_iterations.nil?

  iterations < max_iterations
end

#validate_prompt(values:) ⇒ Hash

validate the prompt

Parameters:

  • values (Hash) —

    The values to validate.

Returns:

  • (Hash) —

    The validated values.

Raises:

  • (RuntimeError) —

    If the prompt is invalid.



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# File 'lib/boxcars/train.rb', line 136

def validate_prompt(values:)
  prompt = values["engine_chain"].prompt
  unless prompt.input_variables.include?(:agent_scratchpad)
    logger.warning("`agent_scratchpad` should be a variable in prompt.input_variables. Not found, adding it at the end.")
    prompt.input_variables.append(:agent_scratchpad)
    case prompt
    when Prompt
      prompt.template += "\n%<agent_scratchpad>s"
    else
      raise ValueError, "Got unexpected prompt type #{type(prompt)}"
    end
  end
  values
end