Question

我正在查看RxJS 5 combineLatest的源代码，并发现了大量带编号参数的调用的排列。

为什么有休息参数时会这样做？

是否有任何即将推出的TypeScript功能会减少这种功能？

我想知道是否与输入休息参数或智能感知有关？

export interface CombineLatestSignature<T> {
  <R>(project: (v1: T) => R): Observable<R>;
  <T2, R>(v2: ObservableInput<T2>, project: (v1: T, v2: T2) => R): Observable<R>;
  <T2, T3, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, project: (v1: T, v2: T2, v3: T3) => R): Observable<R>;
  <T2, T3, T4, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, project: (v1: T, v2: T2, v3: T3, v4: T4) => R): Observable<R>;
  <T2, T3, T4, T5, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, project: (v1: T, v2: T2, v3: T3, v4: T4, v5: T5) => R): Observable<R>;
  <T2, T3, T4, T5, T6, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>, project: (v1: T, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6) => R): Observable<R>;

  <T2>(v2: ObservableInput<T2>): Observable<[T, T2]>;
  <T2, T3>(v2: ObservableInput<T2>, v3: ObservableInput<T3>): Observable<[T, T2, T3]>;
  <T2, T3, T4>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>): Observable<[T, T2, T3, T4]>;
  <T2, T3, T4, T5>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>): Observable<[T, T2, T3, T4, T5]>;
  <T2, T3, T4, T5, T6>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>): Observable<[T, T2, T3, T4, T5, T6]>;

  <R>(...observables: Array<ObservableInput<any> | ((...values: Array<any>) => R)>): Observable<R>;
  <R>(array: ObservableInput<any>[]): Observable<R>;
  <R>(array: ObservableInput<any>[], project: (...values: Array<any>) => R): Observable<R>;
}

Answer 1

所有必须使用相同类型声明休息参数，因此不可能仅使用其他参数来精确建模此特定界面。在没有丢失有用的类型信息的情况下，我没有看到任何方式可以使这个界面更简洁。

为什么在这个TypeScript代码中有如此多的参数排列

1 个答案: