yield from a list of generators created from an array

Answer 1

The map is a good idea, but you need to reduce the resulting array of generator objects to just one generator object:

function *flat(x) {
    if (Array.isArray(x)) 
        yield *x.map(flat).reduce((a, b) => function*() { yield *a; yield *b }());
    else
        yield 'foo' + x;
}

var obj = [1,2,3,[4,5,[6,7,8],9],10];
console.log([...flat(obj)]);

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