Function reduce

Standard reducer for the iterable, extended for fully async syntax + iteration state.

Below is an example of calculating the average from a sequence of numbers:

import {pipe, reduce} from 'iter-ops';

const input = [3, 0, -2, 5, 9, 4];

const i = pipe(input, reduce((p, c, idx, state) => {
    state.sum = (state.sum ?? p) + c;
    return p && state.sum / (idx + 1);
}));

console.log(...i); //=> 3.1666(6)
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See

• Array.reduce