[英]Cannot breakout of foreach loop in scala
i have this below code我有下面的代码
> .foreach("${plist}", "newshole") {
> exec(
> http("get the user id")
> .get("${newshole}/jcr:content.1.json")
> .headers(headers_2)
> .check(bodyString.saveAs("Res1"))
> )
> exec(session => {
> var mynewshole = session("Res1").as[String]
> if (!mynewshole.contains("testingInProgress")) {
> println("Doesn't contain: " + mynewshole)
> (http("post the user id")
> .post("${newshole}/jcr:content")
> .headers(headers_2)
> .formParam("testingInProgress", session.userId))
> exec(http("Create print package")
> .post("/bin/cqtg-create-print-package.do")
> .headers(headers_2)
> .formParam("newsholeId", "${plist}")
> .formParam("digitalMasterId", "1adpy8")
> .check(status.is(200)))
>
> }
> session
> })
> }
i want to break out of :我想摆脱:
> if (!mynewshole.contains("testingInProgress")) {
> println("Doesn't contain: " + mynewshole)
> (http("post the user id")
> .post("${newshole}/jcr:content")
> .headers(headers_2)
> .formParam("testingInProgress", session.userId))
> exec(http("Create print package")
> .post("/bin/cqtg-create-print-package.do")
> .headers(headers_2)
> .formParam("newsholeId", "${plist}")
> .formParam("digitalMasterId", "1adpy8")
> .check(status.is(200)))
>
> }
> session
basically i want break out from the loop when my first condition meet.So i want to use the below code as per scala tutorials but don't know where to put the breakable command as it is giving me errors.基本上我想在我的第一个条件满足时从循环中跳出。所以我想按照 scala 教程使用下面的代码,但不知道在哪里放置可破解命令,因为它给了我错误。
> breakable{
> code ()
> break;
> }
but don't know where to put it.Any Idea????但不知道把它放在哪里。任何想法????
Scala doesn't really offer any easy-to-use break
/ continue
control flow primitives. Scala 并没有真正提供任何易于使用的break
/ continue
控制流原语。 It's not the functional way of doing things.这不是做事的功能方式。
Most of the methods available on Scala collections, like foreach
, are designed to inspect/modify the entire collection. Scala 集合上可用的大多数方法,如foreach
,旨在检查/修改整个集合。 The exceptions include: contains
, corresponds
, exists
, forall
, indexWhere
, etc. You'll note that most (all?) deal with Booleans, either as an argument (a predicate function) or as the return type.例外情况包括: contains
, corresponds
, exists
, forall
, indexWhere
等,你会注意到,大多数(所有?)处理布尔值,无论是作为一个参数(谓语功能)或作为返回类型。
If your algorithm can't be reworked to utilize one of these lazy-evaluated methods then I'd recommend following @pietro909's advice and redesign it as a recursive function which tests for one or more exit conditions on every invocation/recursion.如果您的算法无法重新设计以使用这些惰性评估方法之一,那么我建议您遵循 @pietro909 的建议并将其重新设计为递归函数,该函数在每次调用/递归时测试一个或多个退出条件。
I know that isn't really what you asked for, and it's true you can achieve what you want by inserting a breakable
block in your code, but if you inspect the source you'll see that the breaks are implemented by throwing/catching exceptions, which is pretty inefficient and usually worth avoiding.我知道这是不是真的你要的,你可以通过将实现你想要的这是真的breakable
在你的代码块,但是如果你查看源代码,你会看到符抛出/捕获异常实现,这是非常低效的,通常值得避免。
But if you're determined to go down that road, this should provide some guidance:但是,如果您决心走这条路,这应该会提供一些指导:
scala> import util.control.Breaks
import util.control.Breaks
scala> val mybreaks = new Breaks
mybreaks: scala.util.control.Breaks = scala.util.control.Breaks@69ea3742
scala> import mybreaks.{break, breakable}
import mybreaks.{break, breakable}
scala> breakable {
| (1 to 34).foreach(x => if (x > 9) break else println(x))
| println("all done")
| }
1
2
3
4
5
6
7
8
9
Note: The break
doesn't just terminate the foreach()
statement, it breaks out of the entire breakable
block.注意: break
不仅仅终止foreach()
语句,它打破了整个breakable
块。
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