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distinctObservablePipe

Alternative: distinct$$$

Inlined: distinctObservable, distinct$$

Types​

function distinctObservablePipe<GValue>(
  options?: IDistinctOptions<GValue>,
): IObservablePipe<GValue, GValue>
interface IDistinctOptions<GValue> {
  initialValue?: GValue;
  equal?: (a: GValue, b: GValue) => boolean;
}

Definition​

Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from the last previous value.

The RxJS equivalent is distinctUntilChanged.

It accepts an optional options argument:

  • initialValue: if provided, the pipe is initialized with this value, and the first emitted value is compared with this one (initialValue). Else, the first value is always transmitted.
  • equal: this function is called to compare the previous and current value. By default, it is the strict equality comparison ===.

Diagram​

Algorithm​

Example​

Example​

Emit only distinct values​

const subscribe = pipe$$(of(0, 1, 1, 2, 1), [
  distinct$$$(),
]);

subscribe((value) => {
  console.log(value);
});

Output:

0
1
2
1