declare
fun {start StringToTokenize CurrentState}
    case StringToTokenize
    of nil then nil
    [] H|T then
        case CurrentState
        of 'char' then
            // push char on layer2
            {recurse and if statechange push layer2 to layer3}
        [] 'int' then
            // push to layer2
            {recurse and if statechange push layer2 to layer3}

        end
    end
end