Function scan

scan<T, O>(
reducerFunction: ReduceFunction<T, O>,
initialValue: ValueOrFactory<O>,
): OperationFunction<T, O>
Returns an OperationFunction that yields the result of applying the reducer function to each element of the source.
Type Parameters
- T
  Type of items in the source.
- O
  Type of items to yield.
Parameters
- reducerFunction: ReduceFunction<T, O>
  A function that reduces the source to a single value.
- initialValue: ValueOrFactory<O>
  Initial value or factory function to use as the first argument to the reducer function.
Returns OperationFunction<T, O>
An OperationFunction that yields the result of applying the reducer function to each element of the source.
Example
```
const result = scan<number, number>((prev, curr) => prev + curr, 0)([1, 2, 3]);
console.log([...result]); // [1, 3, 6]
```
- Defined in operations/sync/scan.ts:45