# PCASTLI version 1.8

auto = names("S", "Sigma", "delta", "iota", "F")

# States
auto.S = array("A", "B", "C")

# Alphabet
auto.Sigma = array("a", "b", "c")

makerule = function(start, symbol, end)
{
   a = names("start", "symbol", "end")
   a.start = start
   a.symbol = symbol
   a.end = end
   a
}

# Transition function
auto.delta = array(
   makerule("A", "a", "B"),
   makerule("A", "b", "C"),
   makerule("A", "c", "A"),
   makerule("B", "a", "A"),
   makerule("B", "b", "B"), 
   makerule("B", "c", "C"),
   makerule("C", "a", "A"),
   makerule("C", "b", "B"),
   makerule("C", "c", "C")
)

# Start state
auto.iota = "A"

# Set of accept states
auto.F = array("A", "B")


run_automaton = function(automaton, string)
{
   stringlen = strlen(string)
   state = automaton.iota

   i = 0
   found_rule = 1
   while (found_rule && i < stringlen)
   {
      j = 0
      deltaLen = length(automaton.delta)
      found_rule = 0
      while (!found_rule && j < deltaLen)
      {
         if (state == automaton.delta[j].start
            && string[i] == automaton.delta[j].symbol)
         {
            state = automaton.delta[j].end
            found_rule = 1
         }
         j++
      }
      i++
   }

   i = 0
   foundFinal = 0
   nbFinals = length(automaton.F)
   while (i < nbFinals && !foundFinal)
   {
      if (state == automaton.F[i]) foundFinal = 1
      i++
   }

   if (foundFinal) return("accepted")
   "refused"
}


run_automaton(auto, "c")
run_automaton(auto, "ac")
run_automaton(auto, "aca")