state->start
    input->remember-starting-position
    
    while (input->has-more) {
        if (state->attempt-transition-for (input->current-char)) { # move
            if (state->accepts) {                                  # memo
                last-accept-state = state
                input->remember-accept-position
            }
            input->advance                                         # advance
        } else {
            push (output-queue, token {                            # token
                type = last-accept-state->type
                value = input->last-accepted-string
            })
            input->rewind                                          # rewind
            state = start                                          # restart
            input->remember-starting-position
        }
    }