Don'tcreatestacktraceswhenconfigcan'tbefound

Sometimes you want to distinguish between a value not found, and a default value. For example, in Play there are many times when we only want to do something if a value is configured, one good example is when we offer configuration for third party libraries, and we want that library to be responsible for choosing the default value if it's not configured, so we want to know if no value is configured - this means we don't put a value in reference.conf, nor do we pass a default value to the lookup method.

The only mechanism Typesafe config offers to achieve this is throwing an exception. While not ideal, it's workable with Scala. But it's very slow, because creating stack traces is slow. If Typesafe config is going to use exceptions for control flow like that, then it should not fill in the stack trace of those exceptions. This can be done by overriding the

method on the exceptions it throws to do nothing.

This would fix some significant performance problems in Play, as described here.

该提问来源于开源项目：lightbend/config