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@kjetilv
Created June 11, 2010 15:21
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A trait for setters or stupid, non-cascading objects in general
// A simple trait:
trait CascadingActions {
implicit def tToActioneerT[T](t: T) = Actioneer(t)
case class Actioneer[T](tee: T) {
def withAction(action: (T => Unit)): T =
withActions(action)
def withActions(actions: (T => Unit)*): T = {
actions foreach (_ (tee))
tee
}
}
}
// Yet with nice properties when you're dealing with
// an object that take a lot of setters, and you really
// wish it supported cascading:
def newStupid = {
val stupidTemporaryVariable = new StupidObject
stupidTemporaryVariable setSillyProperty "foo"
stupidTemporaryVariable setAnotherOne "bar"
stupidTemporaryVariable // mention it AGAIN here, just so it gets returned
}
// But instead:
def newStupid = new StupidObject withActions(
_ setSillyProperty "foo",
_ setAnotherOne "bar")
// Wow!
@kjetilv
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kjetilv commented Jun 11, 2010

@retronym: yes, that avoids the issue with StupidObject being final, and it doesn't introduce a new subclass. However, it is no longer a single expression, but is back to being a sequence of statements, the last one being the expression returned:

def newStupid {
    val nso = new StupidObject;
    {
        import nso._
        sillyProperty = "foo"
        anotherOne = "bar"
    }
    nso // ... and an expression at the end
}

@paulp
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paulp commented Jun 11, 2010

re "although I think you mean..." I meant exactly what I wrote; unfortunately the helpful markup processor betrayed me. If you look at the raw text you will see the untainted vision.

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