scala 2.8 control Exception - what is the point?

Question

In the upcoming scala 2.8, a util.control package has been added which includes a break library and a construct for handling exceptions so that code which looks lik

Answer 1

I'd say it's foremost a matter of style of expression.

Beyond being shorter than its equivalent, the new catching() method offers a more functional way to express the same behavior. Try ... catch statements are generally considered imperative style and exceptions are considered side-effects. Catching() puts a blanket on this imperative code to hide it from view.

More importantly, now that we have a function then it can be more easily composed with other things; it can be passed to other higher-order functions to create more sophisticated behavior. (You cannot pass a try .. catch statement with a parametrized exception type directly).

Another way to look at this is if Scala didn't offer this catching() function. Then most likely people would 're-invent' it independently and that would cause code duplication, and lead to more non-standard code. So I think the Scala designers believe this function is common enough to warrant including it in the standard Scala library. (And I agree)

alex