Question

实现像Swift一样的优雅方法是什么

sections.replaceSubrange(sectionIndex ..< (sectionIndex + 1), with: [section])

在科特林吗？

到目前为止，我的代码：

var filters = BehaviorRelay.create<List<FilterSection>>()

 fun updateFilters(type: FilterType, filtersArray: List<Filter>, state: SectionState = SectionState.Loaded){
        val sectionIndex = filters.value.indexOfFirst { it.filterType == type }
        val section =  filters.value[sectionIndex].update(state, filtersArray)
        val sections = filters.value
        //here is where I need to replace the elements
        filters.accept(sections)
    }

Answer 1

标准库中没有内置函数。但是，您可以如下定义扩展名：

fun <T> List<T>.replaceSubrange(subrange: IntRange, withItems: List<T>): List<T> =
    take(subrange.first) + withItems + drop(subrange.endInclusive + 1)

> listOf(1, 2, 3, 4, 5).replaceSubrange(1..3, listOf(0, 0, 0, 0))
[1, 0, 0, 0, 0, 5]

或者，如果您只需要在列表中插入子列表：

fun <T> List<T>.insertSubrangeAt(index: IntRange, items: List<T>): List<T> =
    take(atIndex) + items + drop(atIndex)

> listOf(1, 2, 3, 4, 5).insertSubrangeAt(1, listOf(0, 0, 0, 0))
[1, 0, 0, 0, 0, 2, 3, 4, 5]

Swift在Kotlin中的replaceSubrange

1 个答案: