CODEWITHSUNDEEP
androidkotlin
Sergio
Sergio

Reputation: 798

Is there any possibility to make a try catch function as an infix function?

I am trying to create an infix function to my project to check the result of a try catch function.

I saw a solution out there but is passing the block as parameter and running that block inside the tryOrNull function like that.

fun <T : Any> tryOrNull(body: () -> T?): T? {
//the body returns T? so that you can give up the work by returning null
return try {
body()
} catch (e: Exception) {
e.printStackTrace()
null
}

}

and using like that 

fun parse(): MyData? {
return tryOrNull { parse1() }
?: tryOrNull { parse2() }
?: tryOrNull { parse3() }

}

this info I saw here

But I would like to know if there is a different way to this something like that 

fun parse(): MyData? {
return parse().tryOrNull() ?: false
}

I would like to create an infix or extension function but I don't know how to manage at all. Thanks!.

Upvotes: 2

Views: 280

Answers (1)

Tenfour04
Tenfour04

Reputation: 93902

The syntax you suggested (parse().tryOrNull()) would be impossible because parse() would be called and return a result before it reached tryOrNull().

However,

::parse.tryOrNull()

or 

{ parse() }.tryOrNull()

are possible if you write your utility function like this:

inline fun <T> (() -> T).tryOrNull(): T? = runCatching(this)
    .also { it.exceptionOrNull()?.printStackTrace() }
    .getOrNull()

But I think the original syntax you showed is clearer. It makes more semantic sense to see the thing you are calling wrapped in the tryOrNull call instead of tacking tryOrNull on like an afterthought.

Upvotes: 2

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