Try with exception logging

Question

Scala\'s Try is very useful.

I\'d like to use that pattern, but log all exceptions.

How can I do this?

Answer 1

Starting Scala 2.13, the chaining operation tap can be used to apply a side effect (in this case some logging) on any value while returning the original value:

import util.chaining._

val x = Try("aa".toInt).tap(_.failed.foreach(println))
// java.lang.NumberFormatException: For input string: "aa"
// x: Try[Int] = Failure(java.lang.NumberFormatException: For input string: "aa")

Or an equivalent pattern matching version:

val x = Try("aa".toInt).tap { case Failure(e) => println(e) case _ => }
// java.lang.NumberFormatException: For input string: "aa"
// x: Try[Int] = Failure(java.lang.NumberFormatException: For input string: "aa")

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The tap chaining operation applies a side effect (in this case println or some logging) on a value (in this case a Try) while returning the original unmodified value on which tap is applied (the Try):

def tap[U](f: (A) => U): A