Class: Ibex::LALR::IELR::Pipeline

Inherits:
Object
  • Object
show all
Defined in:
lib/ibex/lalr/ielr/pipeline.rb

Overview

Coordinates the canonical-free direct IELR phases. The returned profile deliberately reports canonical metrics as unavailable.

Instance Method Summary collapse

Constructor Details

#initialize(grammar, sets, starts: nil, profile: false) ⇒ Pipeline

Returns a new instance of Pipeline.



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# File 'lib/ibex/lalr/ielr/pipeline.rb', line 21

def initialize(grammar, sets, starts: nil, profile: false)
  @grammar = grammar
  @sets = sets
  @starts = starts || grammar.starts
  @profile = profile
end

Instance Method Details

#build ⇒ Object 



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# File 'lib/ibex/lalr/ielr/pipeline.rb', line 29

def build
  states, transitions = LR0Collection.new(@grammar, starts: @starts).build
  seeds = @starts.each_with_index.map do |name, index|
    augmented = -1 - @grammar.starts.index(name)
    [index, [augmented, 0], 0]
  end
  initial_propagation = LookaheadPropagation.new(
    @grammar, @sets, states, transitions, seeds: seeds
  )
  items = initial_propagation.build
  goto_follows = GotoFollows.new(
    @grammar, @sets, states, transitions, @starts.each_index.to_a, start_names: @starts
  )
  splitter = StateSplitter.new(@grammar, states, transitions, items, goto_follows)
  _split_items, split_transitions = splitter.build
  split_states = splitter.states.map { |state| states.fetch(state.lalr_isocore) }
  phase4_items = LookaheadPropagation.new(
    @grammar, @sets, split_states, split_transitions, seeds: seeds
  ).build
  profile = {
    construction_states: phase4_items.length,
    canonical_states: nil,
    strategy: :ielr_direct,
    lr0_states: @profile ? states.length : nil,
    lr0_items: @profile ? states.sum(&:length) : nil,
    canonical_items: nil,
    propagation_edges: @profile ? initial_propagation.propagation_edge_count : nil,
    ielr_initial_partitions: nil,
    ielr_final_partitions: nil,
    ielr_annotations: splitter.annotations.sum(&:length),
    ielr_annotated_states: splitter.annotations.count { |entries| !entries.empty? },
    ielr_inadequacies: splitter.inadequacies.sum(&:length),
    ielr_split_stable_discarded: splitter.split_stable_discarded,
    ielr_lalr_states: states.length,
    ielr_split_states: splitter.split_states,
    ielr_unreachable_removed: 0,
    ielr_remergeable_candidates: nil
  }
  [phase4_items, split_transitions, profile]
end