common/observable.js


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/**
 * part of Hachette
 * Facilitate listening to events
 *
 * Copyright (C) 2021 Wojtek Kosior
 * Redistribution terms are gathered in the `copyright' file.
 */

function make()
{
    return new Set();
}

function subscribe(observable, cb)
{
    observable.add(cb);
}

function unsubscribe(observable, cb)
{
    observable.delete(cb);
}

function broadcast(observable, event)
{
    for (const callback of observable)
	callback(event);
}

const observables = {make, subscribe, unsubscribe, broadcast};

/*
 * EXPORTS_START
 * EXPORT observables
 * EXPORTS_END
 */