promise type

promise.join

def promise.join(*args) -> promise

Join a set of promises together into a single promise.

Given a series of promises, p4 = p1.join(p2, p3) will produce a promise where the value is promise that resolves to a tuple containing the three values, those from p1, p2 and p3 respectively.

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promise.map

def promise.map(func, /) -> promise

Given a promise, apply a function to the value it contains, producing a promise with the resulting value.