Bikeshed-ish issue: Optional

David M. Lloyd david.lloyd at
Thu Mar 3 03:42:05 UTC 2016

I notice that Jigsaw is making arguably excessive use of Optional. 
Reinier Zwitzerloot [1] quoted Brian Goetz about this topic; the full 
quote [2] is as follows:

"Of course, people will do what they want. But we did have a clear 
intention when adding this feature, and it was not to be a general 
purpose Maybe or Some type, as much as many people would have liked us 
to do so. Our intention was to provide a limited mechanism for library 
method return types where there needed to be a clear way to represent 
"no result", and using null for such was overwhelmingly likely to cause 

"For example, you probably should never use it for something that 
returns an array of results, or a list of results; instead return an 
empty array or list. You should almost never use it as a field of 
something or a method parameter.

"I think routinely using it as a return value for getters would 
definitely be over-use.

"There's nothing wrong with Optional that it should be avoided, it's 
just not what many people wish it were, and accordingly we were fairly 
concerned about the risk of zealous over-use."

Incidentally [1] is also the go-to reference when people have questions 
about Optional<> in the ##java IRC channel on



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