heap-data-structure/specification

export function DummyHeap(compare) {
    this.compare = function (a, b) {
        return compare(a.value, b.value);
    };

    this.array = [];
    this.length = 0;
}

DummyHeap.Reference = function (value) {
    this.value = value;
};

DummyHeap.prototype.head = function () {
    if (this.length === 0) return undefined;

    return this.array[0].value;
};

DummyHeap.prototype.headreference = function () {
    if (this.length === 0) return null;

    return this.array[0];
};

DummyHeap.prototype.pop = function () {
    if (this.length === 0) return undefined;

    --this.length;
    return this.array.shift().value;
};

DummyHeap.prototype.popreference = function () {
    if (this.length === 0) return null;

    --this.length;
    return this.array.shift();
};

DummyHeap.prototype.push = function (value) {
    const reference = new DummyHeap.Reference(value);

    this.pushreference(reference);

    return reference;
};

DummyHeap.prototype.pushreference = function (reference) {
    this.array.push(reference);

    this.array.sort(this.compare);

    ++this.length;
};

DummyHeap.prototype.merge = function (other) {
    this.array = this.array.concat(other.array).sort(this.compare);

    this.length += other.length;
};

DummyHeap.prototype.update = function (reference, value) {
    reference.value = value;

    this.array.sort(this.compare);
};

DummyHeap.prototype.decreasekey = DummyHeap.prototype.update;

DummyHeap.prototype.increasekey = DummyHeap.prototype.update;

DummyHeap.prototype.delete = function (reference) {
    this.array.splice(this.array.indexOf(reference), 1);
    --this.length;
};