使用TypeScript类型检查器查看两种类型是否可分配 [英] Using the TypeScript type checker to see if two types are assignable

问题描述

我正在构建一个小的脚本，该脚本使用 TypeScript编译器API ，其源可以在此处。我检查了这些类的成员，以了解它们是如何相互链接的。

I'm building a small script that scans for all interfaces that have a member of a given type using the TypeScript Compiler API, of which the source can be found here. I inspect the members of these classes to see how they are interlinked.

我的问题是：如何知道一个类型何时可以分配给另一个类型？我在 TypeChecker 中搜索了一种方法，但找不到。有没有人有任何指针？以下是应该能够进行分析的示例：

My question is: how do I know when a type is assignable to another type? I searched the TypeChecker for a method but I couldn't find one. Does anyone by any chance have any pointers? Here's an example of something that should be able to get analysed:

export enum ASTKind {
  Number,
  Addition,
  Multiplication,
}

export interface AST {
  kind: ASTKind  
}

export interface BinaryExpression extends AST {
  left: AST
  right: AST
}

export interface Addition extends BinaryExpression {
  kind: ASTKind.Addition 
}

export interface Multiplication extends BinaryExpression {
  kind: ASTKind.Multiplication 
}

本质上，我想要一个谓词，说明 ASTKind.Multiplication 是否可分配给 ASTKind （在这种情况下是正确的。）。

Essentially, I want a predicate that says whether ASTKind.Multiplication is assignable to ASTKind (which is true in this case).

推荐答案

我找到了它：好像是当前不可能：

I've found it: seems like it is currently not possible:

• 在TypeChecker中暴露isTypeAssignableTo吗？


• 提案：类型关系API


• 可分配性在API中检查

• Expose isTypeAssignableTo in TypeChecker?
• Proposal: Type Relationship API
• Assignability checks in API

我创建了自己的叉子公开了此功能。我将尝试维护它，以便如果有人感兴趣的话，他或她可以使用分叉直到上游跟随。

I created my own fork which exposes this function. I will try to maintain it so if anyone is interested he or she can just use the fork until upstream follows.

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