Class: Lrama::Counterexamples

Inherits:
Object
  • Object
show all
Defined in:
lib/lrama/counterexamples.rb,
lib/lrama/counterexamples/node.rb,
lib/lrama/counterexamples/path.rb,
lib/lrama/counterexamples/triple.rb,
lib/lrama/counterexamples/example.rb,
lib/lrama/counterexamples/derivation.rb,
lib/lrama/counterexamples/state_item.rb

Overview

See: https://www.cs.cornell.edu/andru/papers/cupex/cupex.pdf 4. Constructing Nonunifying Counterexamples

Defined Under Namespace

Classes: Derivation, Example, Node, Path, StateItem, Triple

Constant Summary collapse

PathSearchTimeLimit =

10 sec

10
CumulativeTimeLimit =

120 sec

120

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(states) ⇒ Counterexamples

Returns a new instance of Counterexamples.



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# File 'lib/lrama/counterexamples.rb', line 38

def initialize(states)
  @states = states
  @iterate_count = 0
  @total_duration = 0
  @exceed_cumulative_time_limit = false
  @triples = {}
  setup_state_items
  setup_transitions
  setup_productions
end

Instance Attribute Details

#productions ⇒ Object (readonly)

: Hash[StateItem, Set[StateItem]]



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# File 'lib/lrama/counterexamples.rb', line 35

def productions
  @productions
end

#transitions ⇒ Object (readonly)

@rbs! @states: States @iterate_count: Integer @total_duration: Float @exceed_cumulative_time_limit: bool @state_items: Hash[[State, State::Item], StateItem] @triples: Hash[Integer, Triple] @transitions: Hash[[StateItem, Grammar::Symbol], StateItem] @reverse_transitions: Hash[[StateItem, Grammar::Symbol], Set[StateItem]] @productions: Hash[StateItem, Set[StateItem]] @reverse_productions: Hash[[State, Grammar::Symbol], Set[StateItem]] # Grammar::Symbol is nterm @state_item_shift: Integer



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# File 'lib/lrama/counterexamples.rb', line 34

def transitions
  @transitions
end

Instance Method Details

#compute(conflict_state) ⇒ Object 



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# File 'lib/lrama/counterexamples.rb', line 56

def compute(conflict_state)
  conflict_state.conflicts.flat_map do |conflict|
    # Check cumulative time limit for not each path search method call but each conflict
    # to avoid one of example's path to be nil.
    next if @exceed_cumulative_time_limit

    case conflict.type
    when :shift_reduce
      # @type var conflict: State::ShiftReduceConflict
      shift_reduce_example(conflict_state, conflict)
    when :reduce_reduce
      # @type var conflict: State::ReduceReduceConflict
      reduce_reduce_examples(conflict_state, conflict)
    end
  rescue Timeout::Error => e
    STDERR.puts "Counterexamples calculation for state #{conflict_state.id} #{e.message} with #{@iterate_count} iteration"
    increment_total_duration(PathSearchTimeLimit)
    nil
  end.compact
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/lrama/counterexamples.rb', line 50

def to_s
  "#<Counterexamples>"
end