Scala code often needs to deal with null references, unfortunately. Such is the price of Java interoperability. One of my favourite utility methods is:
Scala 2.8 offers this using Option(ref) instead of ?(ref). However, I can't figure out why the Scala 2.8 method accepts non-reference values as well.
Another simple thing that may come in handy is an extractor for non-null values:
What's the advantage of using an extractor? Say you have a collection of references, some of which may be null, and you want to ignore the null references:
1 comment:
The Option apply method has no constraint because the constraint doesn't accomplish anything, and it makes the method less general. Making up an example:
def f[T](x: T) = Option(x).toList
You can't write that method with ? because the constraint would needlessly prevent it.
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