[英]Better syntax for Scala anonymous function?
Experimenting with Scala... I'm trying to define something analogous to the "@" hack in PHP (which means, ignore any exception in the following statement). 尝试使用Scala ...我试图在PHP中定义类似于“@”hack的东西(这意味着,忽略以下语句中的任何异常)。
I managed to get a definition that works: 我设法得到一个有效的定义:
def ignoreException(f: () => Unit) = { try { f(); } catch { case e: Exception => println("exception ignored: " + e); } }
And use it like this: 并像这样使用它:
ignoreException( () => { someExceptionThrowingCodeHere() } );
Now here is my question... Is there anyway I can simplify the usage and get rid of the () =>, and maybe even the brackets? 现在这里是我的问题......无论如何,我可以简化用法并摆脱()=>,甚至括号?
Ultimately I'd like the usage to be something like this: 最终我希望用法是这样的:
`@` { someExceptionThrowingCodeHere(); }
@
is reserved in Scala (for pattern matching), but would you accept @@
? 在Scala中保留@
(用于模式匹配),但是你会接受@@
吗?
scala> def @@(block: => Unit): Unit = try {
block
} catch {
case e => printf("Exception ignored: %s%n", e)
}
$at$at: (=> Unit)Unit
scala> @@ {
println("before exception")
throw new RuntimeException()
println("after exception")
}
before exception
Exception ignored: java.lang.RuntimeException
I'm not convinced this is a good idea, however ☺ 我不相信这是个好主意,不过☺
You don't have to use a function as your parameter, a "by-name" parameter will do: 您不必使用函数作为参数,“by-name”参数将执行以下操作:
def ignoreException(f: =>Unit) = {
try {
f
}
catch {
case e: Exception => println("exception ignored: " + e)
}
}
ignoreException(someExceptionThrowingCodeHere())
Eric. 埃里克。
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