爱折腾的小雨
只要心在跳，就要一直折腾。
获得徽章 8
- @每日英语7
Item 7: Think of Types as Sets of Values
- Think of types as sets of values(the type's domain). These sets can either be finite(e.g., boolean or literal types) or infinite(e.g., number or string)
- 思考值设置的类型（类型的有限范围）。这些设置不单可以是有限的（boolean 或者 文字类型）而且可以说无限的（number 或者 string）
- TypeScript types form intersecting sets rather than a strict hierarchy. Two types can overlap without either being a subtype of the other.
- TS 的类型构建与相交的设置而不是严肃的登记制。两种类型可以重叠而不需要一方称为另外一方的子类型
- Remember that an object can still belong to a type even if it has additional properties that were not mentioned in the type declaration
- 记住一个对象仍然属于它之前配置了类型，即便它有了额外的在类型声明中没有被提及的属性
- Type operations apply to a set's domain. The intersection of A and B is the intersection of A's domain and B's domain. For object types, this means that values in A & B have the properties of both A and B
- 类型运行适用于设置的领域。A 和 B 的交集就是 A 领域和 B 领域的交集。对于一个对象类型的值，这意味着这个值在 A & B 类型中，就需要同时拥有 A 和 B 的属性展开赞过 评论1 - @每日英语6
Item6: Use Your Editor to Interrogate and Explore the Type System
- Take advantage of the Typescript language services by using an editor that can use them.
- 通过使用编辑器在 TS 语言系统中获取优势，编辑器可以使用 TS 语言系统；
- Use your editor to build an intuition for how the type system works and how Typescript infers types.
- 使用你的编辑器去构建一个直觉，类型是怎么样运行的，TS 怎样推断出类型的。
- Know how to jump into type declaration files to see how they model behavior
- 知道怎么条件类型断言文件去查看它们如何塑造行为。展开评论点赞 - @每日英语4
Get Comfortable with Structural Typing
- Understanding that Javascript is duck typed and Typescript uses structural typing to model this: values assignable to your interfaces might have properties beyond those explicitly listed in your type declaration. Types are not "sealed".
- Be aware that classes also follow structural typing rules. You may not have an instance of the class you expect.
- Use structural typing to facilitate unit testing.展开评论点赞 - @每日英语3Understand That Code Generation Is Independent Of Types
- Code generation is independent of type system. This means that Typescript types cannot affect the runtime behavior or performance of your code.
- It is possible for a program with type errors to build code
- Typescript types are not available at runtime. To query a type at runtime, you need some way to reconstruct it. Tagged unions and property are common ways to do this. Some constructs, such as class, introduce both a Typescript type and a value that is available at runtime.展开赞过 评论1 - @每日英语2
Know Which Typescript Options You're Using
- The Typescript compiler includes several settings which affect core aspects of the language
- TS 编译器包含了很多可以影响 ts 核心方面的设置
- Configure Typescript using tsconfig.json rather than command-line options
- 使用 tsconfig.json 来配置 TS 而不是命令行属性
- Turn on noImplicitAny unless you are transitioning a Javascript project to Typescript;
- 除非你正在从JS 转移到 TS，否则打开 noImplicitAny 配置
- Use strictNullChecks to prevent "undefined is no an object" style runtime error
- 使用 strictNullChecks 配置来保护 "undefined 不是对象"这类型的运行时错误
- Aim to enable strict to get the most thorough checking that Typescript can offer
- 以 TS 能够提供的，可以使得项目能得到更严厉彻底的检测为目标；展开赞过 评论1