A sound gradual type system ensures that untyped components of a program can never break the guarantees of statically typed components. This assurance relies on runtime checks, which in turn impose performance overhead in proportion to the frequency and nature of interaction between typed and untyped components. The literature on gradual typing lacks rigorous descriptions of methods for measuring the performance of gradual type systems. This gap has consequences for the implementors of gradual type systems and developers who use such systems. Without systematic evaluation of mixed-typed programs, implementors cannot precisely determine how improvements to a gradual type system affect performance. Developers cannot predict whether adding types to part of a program will significantly degrade (or improve) its performance. This paper presents the first method for evaluating the performance of sound gradual type systems. The method quantifies both the absolute performance of a gradual type system and the relative performance of two implementations of the same gradual type system. To validate the method, the paper reports on its application to 20 programs and 3 implementations of Typed Racket.

中文翻译：

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如何评估渐进式系统的性能

一个健全的渐进类型系统确保程序的无类型组件永远不会破坏静态类型组件的保证。这种保证依赖于运行时检查，这反过来又会根据类型化组件和非类型化组件之间交互的频率和性质施加性能开销。关于渐进类型的文献缺乏对衡量渐进类型系统性能的方法的严格描述。这种差距会对渐进类型系统的实现者和使用此类系统的开发人员产生影响。如果没有对混合类型程序的系统评估，实现者就无法准确确定对渐进类型系统的改进如何影响性能。开发人员无法预测向程序的一部分添加类型是否会显着降低（或提高）其性能。本文介绍了评估声音渐变型系统性能的第一种方法。该方法量化了渐变类型系统的绝对性能和同一渐变类型系统的两个实现的相对性能。为了验证该方法，本文报告了它在 20 个程序和 3 个 Typed Racket 实现中的应用。