Question

我很难确定<代码>Result的类型,例如:

<代码>Result应为以下模式之一:

type Result<Some> = { code: 0; some_result: ...}
// or
type Result = { code: NonZero; message: string}

如何分类?

或许这个问题可以分为:

implement NonZero (p.s. Exclude<number, 0> does not work)
give typing to the generic Result

Updates

我写了以下工作纲要:

type Result<TCode extends number, T extends {} = {}> = TCode extends 0
  ? { code: 0; } & T
  : { code: TCode; reason: string };

type SomeResult = {some_result: string}

function getSomeResult(): Result<0 | -1 | 6007 | 114514, SomeResult> {
  return {
    code: 0,
    some_result:   
  }
}

const result = getSomeResult()

switch (result.code) {
  case 0:
    // this is wrong: reason should be void
    result.reason
    // this is ok:
    result.some_result
    break
  default:
    // this is ok: there s always a reason when code is non-zero
    result.reason
}

现在,STS汇编商可以推断其他财产无效,但我需要把所有可能的非零件印成“代码<>/代码>的类型参数。

如何分类<代码>NonZero

Answer 1

enum Codes {
    Pass,
    Foo,
    Bar
}

type Result<Code extends Codes, Some=undefined> = Code extends Codes.Pass ? { code: Codes.Pass; some: Some} 
  : { code: Exclude<Codes,Codes.Pass>; message: string}

const r0: Result<0, {name:string}> = { code: 0, some:{name: ""} };
const r1: Result<1> = { code: 1, message:"foo" };

Updates

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