This article presents a visualization tool for designing and debugging deterministic finite-state machines in FSM -- a domain specific language for the automata theory classroom. Like other automata visualization tools, users can edit machines and observe their execution, given some input. Unlike other automata visualization tools, the user is not burdened nor distracted with rendering a machine as a graph. Furthermore, emphasis is placed on the design of machines and this article presents a novel design recipe for deterministic finite-state machines. In support of the design process, the visualization tool allows for each state to be associated with an invariant predicate. During machine execution, the visualization tool indicates if the proposed invariant holds or does not hold after each transition. In this manner, students can validate and debug their machines before attempting to prove partial correctness or submitting for grading. In addition, any machine edited with the visualization tool can be rendered as executable code. The interface of the visualization tool along with extended examples of its use are presented.

中文翻译：

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FSM 中确定性有限状态机的可视化设计和调试

本文介绍了一种用于在 FSM 中设计和调试确定性有限状态机的可视化工具——一种用于自动机理论课堂的领域特定语言。与其他自动机可视化工具一样，给定一些输入，用户可以编辑机器并观察它们的执行情况。与其他自动机可视化工具不同，用户不会因为将机器渲染为图形而感到负担或分心。此外，重点放在机器的设计上，本文提出了确定性有限状态机的新颖设计方法。为了支持设计过程，可视化工具允许每个状态与一个不变的谓词相关联。在机器执行期间，可视化工具会指示建议的不变量在每次转换后是否成立。以这种方式，学生可以在尝试证明部分正确性或提交评分之前验证和调试他们的机器。此外，使用可视化工具编辑的任何机器都可以呈现为可执行代码。展示了可视化工具的界面及其使用的扩展示例。