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simulator.rb
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simulator.rb
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# frozen_string_literal: true
require "strscan"
module ActionDispatch
module Journey # :nodoc:
module GTG # :nodoc:
class MatchData # :nodoc:
attr_reader :memos
def initialize(memos)
@memos = memos
end
end
class Simulator # :nodoc:
INITIAL_STATE = [ [0, nil] ].freeze
attr_reader :tt
def initialize(transition_table)
@tt = transition_table
end
def memos(string)
input = StringScanner.new(string)
state = INITIAL_STATE
start_index = 0
while sym = input.scan(%r([/.?]|[^/.?]+))
end_index = start_index + sym.length
state = tt.move(state, string, start_index, end_index)
start_index = end_index
end
acceptance_states = state.each_with_object([]) do |s_d, memos|
s, idx = s_d
memos.concat(tt.memo(s)) if idx.nil? && tt.accepting?(s)
end
acceptance_states.empty? ? yield : acceptance_states
end
end
end
end
end