import { isPromise } from './isPromise.js';
import type { PromiseOrValue } from './PromiseOrValue.js';
export function promiseReduce<T, U>(
values: Iterable<T>,
callbackFn: (accumulator: U, currentValue: T) => PromiseOrValue<U>,
initialValue: PromiseOrValue<U>,
): PromiseOrValue<U> {
let accumulator = initialValue;
for (const value of values) {
accumulator = isPromise(accumulator)
? accumulator.then((resolved) => callbackFn(resolved, value))
: callbackFn(accumulator, value);
}
return accumulator;
}