if edge.prefix and starts_with(frag, edge.prefix) then
    if edge.suffix and ends_with(frag, edge.suffix) then
      Current_state = edge.target
      break
    end
  end
      Current_state = edge.target
      break
    end
  end
end
function switch_color_based_on_suffix(frag)
  if Next_state[Current_state] == nil then
    return
  end
  frag = rtrim(frag)
  for _,edge in pairs(Next_state[Current_state]) do

function rfind(s, pat, i, plain)

-- TODO: avoid the expensive reverse() operations
-- Particularly if we only care about literal matches, we don't need all of string.find

function rfind(s, pat, i, plain)