如何很好地阅读& quot;替代& amp;"线? [英] How to nicely read "alternating" lines?

问题描述

我有一个文本文件，其中包含遵循替代模式的行，例如:

I have a text file that contains lines that follow an alternate pattern, like:

name: SomeName 
counterA: 0, counterB: 0, counterC: 0
name: SomeNameB 
counterA: 1, counterB: 2, counterC: 3
...

我想编写一个简单的解析器来推送SameName，并将计数器A到C推送到一个新对象中.

I want to write a simple parser that pushes SameName, and the counters A to C into a new object.

因此，基本上，任务是总是一起处理两条行.

So the task is basically to process always two lines together.

我从以下代码开始:

fun readFileAsLinesUsingReadLines(fileName: String): List<String> = File(fileName).readLines()

fun main(args: Array<String>) {
    val lines = readFileAsLinesUsingReadLines("Whatever")
    for (i in (0 .. lines.size-1 step 2)) {
        println(lines[i]+lines[i+1])
    }
}

是的，可以打印

name: SomeName counterA: 0, counterB: 0, counterC: 0

然后我可以进一步解析.

which I can then further parse.

但是我发现(0 .. lines-size-1 step)的用法不是很优雅.

But I find that usage of (0 .. lines-size-1 step) to be not very elegant.

是否有更优雅或更多科特林"的方式来获取这些信息?

Are there more elegant, or "more kotlin" ways of pulling that information?

推荐答案

使用

With useLines, you can read the lines as a (lazy) sequence, and then use chunked with a transform lambda to parse and format as you see fit:

val result = File("file.txt").useLines { lines ->
    lines.chunked(2) { (l1, l2) -> l1 + l2 }.toList()
}

result.forEach { println(it) }

如果出于某种原因要首先将所有内容流式传输到内存中，则还可以使用

If, for some reason, you want to stream everything into memory first, you can also use readLines with the list-based version of chunked:

val result = File("file.txt").readLines().chunked(2) { (l1, l2) -> l1 + l2 }

result.forEach { println(it) }

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