class Kleene::BatchMatchTracker

def add_empty_match(nfa_with_dead_end, token_index)
  positions = empty_match_positions(nfa_with_dead_end)
  positions << token_index
end

def add_end_of_match(nfa_with_dead_end, token_index)
  # puts "add_end_of_match(#{nfa.object_id}, #{token_index})"
  positions = end_positions(nfa_with_dead_end)
  positions << token_index
end

def add_match(nfa, match)
  matches = matches_for(nfa)
  matches << match
end

def add_start_of_candidate_match(nfa_with_dead_end, token_index)
  # puts "add_start_of_candidate_match(#{nfa.object_id}, #{token_index})"
  positions = start_positions(nfa_with_dead_end)
  positions << token_index
end

def empty_match_positions(nfa)
  empty_matches[nfa] ||= Array.new
end

def end_positions(nfa)
  match_end_positions[nfa] ||= Array.new
end

def initialize
  reset
end

def invert_candidate_match_start_positions # : Hash(Int32, Array(NFA))
  index_to_nfas = Hash.new
  candidate_match_start_positions.each do |nfa_with_dead_end, indices|
    indices.each do |index|
      nfas = index_to_nfas[index] ||= Array.new
      nfas << nfa_with_dead_end
    end
  end
  index_to_nfas
end

def matches_for(nfa)
  matches[nfa] ||= Array.new
end

def reset
  @candidate_match_start_positions = Hash.new
  @match_end_positions = Hash.new
  @empty_matches = Hash.new
  @matches = Hash.new
end

def start_positions(nfa)
  candidate_match_start_positions[nfa] ||= Array.new
end