What does it mean for a type system or language to be "sound"?
2023年12月14日 · A type system assigns a type to a program (or expression). The assignment is sound when indeed the evaluation of that program (or expression) always yields a value of that type. As extension of this, a type system is sound when all its type assignments are sound, that it, reflect the evaluation of the program (or expression).
Type system - Wikipedia
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type (for example, integer, floating point, string) to every term (a word, phrase, or other set of symbols).
Soundness and Completeness of the Type System | Logan's Note
2014年11月12日 · A type-system is sound implies that all of type-checked programs are correct (in the other words, all of the incorrect program can't be type checked), i.e. there won't be any false negative. A type-system is complete implies that all of the correct program can be accepted by the type checker, i.e. there won't be any false positive [2] .
类型系统里的概念 Soundness 和形式系统中的概念一致 …
你说的“每一步reduction后类型不变”的性质叫做“Subject reduction”，是type system的一种重要性质，也是证明type soundness的常用方法之一，但不是唯一的方法。 type system和形式系统（后者我并不熟悉，可能有误）的区别主要有： 形式系统没有语义。
类型系统简介 - 知乎 - 知乎专栏
类型系统(type system)的基本目标是防止程序在运行时发生类型错误。当且仅当语言运行时不存在任何形式的类型错误，那么它就是sound的。soundness是类型系统研究的重要目标。 对类型系统的描述
17 Safety and Soundness - Brown University
In a sound type system, progress offers a proof that, because this term types, and is not already a value, it can take a step of execution— which it clearly can. After one step the program reduces to 5 + 6 .
if at all possible and feasible, whole languages could be shown to be type sound. In this introductory section we present an informal nomenclature for typing, execution er- rors, and related concepts.
CIS 547 - Type Systems - Part I
Explain the concept of Type Soundness and the guarantee that a sound type system provides for well-typed programs. Understand the relationship between types in a type system and abstract values in other forms of static analysis.
Theorem 6.8 (Type Soundness) Suppose (a) λ ‘ c : ρ c is well-typed (b) µ ‘ c ⇒ µ0 execution one (c) υ ‘ c ⇒ υ0 execution two (d) dom(µ) = dom(υ) = dom(λ) (e) υ(l) = µ(l) for all l such that λ(l) ≤ τ the same low inputs Then υ0(l) = µ0(l) for all l such that λ(l) ≤ τ. the same low outputs
Dart 语言里的类型体系 | Dart
术语 sound Dart 和 type safe Dart 通常可互换使用。 你可能还会看到术语 strong mode 。 strong mode 是一种在Dart 1.x中可选的功能，可为类型安全提供部分支持。 The terms Dart and Dart are often used interchangeably. You might also see the term . Strong mode was an opt-in Dart 1.x feature that provided partial support for type safety. 有关 Dart 语言的完整介绍（包括类型），请参阅 语言指南。