如何在不可变地图中对项目进行排序(交换)?

问题描述：

我想交换项目在Map内的不可变列表内，例如:

I want to swap items inside an immutable list within a Map, example:

const Map = Immutable.fromJS({
    name:'lolo',
    ids:[3,4,5]
});

我正在尝试使用拼接来进行交换，也尝试过使用insert()不可变方法.

i am trying to use splice to do the swapping, also tried with insert() an Immutable method.

让我说我想从[3, 4, 5]交换到[3, 5, 4]，我正在进行类似以下的事情:

Lets say i want to swap from [3, 4, 5] to [3, 5, 4], i am truing something like this:

list.set('ids', list.get('ids').splice(2, 0, list.get('ids').splice(1, 1)[0])

使用 Immutable.js 对不可变数据结构中的元素进行排序的最佳方法是什么?

What's the best way to sort elements inside an Immutable data structures with Immutable.js ?

答

您应使用 List.withMutations() 为此:

You should use Map.update() and List.withMutations() for that matter:

map.update('ids', idsList => idsList.withMutations(function (idsList) {
    let temp = idsList.get(2);
    return idsList.set(2, idsList.get(1)).set(1, temp);
}));

请注意，我将您的list重命名为map-实际上是Map.

对于简单的排序，请选择

Notice that I renamed your list to map - this is actually a Map.

And for simple sorting go for

map.update('ids', idsList => idsList.sort(function (a, b) {
    // magic
});

如何在不可变地图中对项目进行排序(交换)?

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