An or function which returns the first non empty optional

[cbefus]

something like:

return Optional.empty() \
     .or(Optional.empty()) \
     .or(Optional.of(3)) \
     .or(Optional.of(4))

would return Optional.of(3) where as:

return Optional.empty() \
     .or(Optional.empty()) \
     .or(Optional.empty())

would return Optional.empty()

It would also be nice if we could pass suppliers, such that we only execute a supplier if the result of the previous suppliers was empty.

[dpassen]

For documentation's sake, the solution here is Python's built-in or.

The first example can be done as follows:

return Optional.empty() or \
       Optional.empty() or \
       Optional.of(3) or \
       Optional.of(4)

and the second:

return Optional.empty() or \
       Optional.empty() or \
       Optional.empty()