Oh no, you are no using xyz_() you are overriding =. So you define xyz_=(x:Int) but to call it you do o.xyz = 5 The reason this is nice is because you can start with a simple var xyz and not need any getter/setter. Then later when you need to change the behavior of the get you make def xyz = ... and none of the calling code changes. Later still you decide you need to override the setter you do def xyz_=(x: Int)... and that overrides o.xyz=5, again without changing the calling code.
Basically the point is that scala generates these getters and setters no matter what so you might as well use the official scala mechanism. Since I am only semi-scala literate any of the above may be wrong. -Jay On Fri, May 25, 2012 at 9:42 AM, Jun Rao <jun...@gmail.com> wrote: > I think separating out the getter and setter makes the implementation > cleaner. I am not sure how intuitive it is to use xyz_() as the setter, > although it is concise. > > Thanks, > > Jun > > On Tue, May 22, 2012 at 9:13 PM, Jay Kreps <jay.kr...@gmail.com> wrote: > > > We are a little inconsistent in our use of setters and getters. I think > for > > the most part well-written code shouldn't have too many setters and > getters > > (especially setters) since they expose internal details of the object. > But > > sometimes you need them. I see three common conventions: > > > > 1. Java-style getXyz() and/or setXyz() method > > 2. xyz() plus semantically named setter that describes what it does. > > 3. In some newer code I see xyz(x: Option[Int]) > > > > There is also a forth option. My understanding of the proper scala idiom > > was actually that scala automatically created get and set methods for > you, > > and the appropriate thing to do is to override these. This is described > > here: > http://www.codecommit.com/blog/scala/scala-for-java-refugees-part-2 > > > > Essentially you can start with just > > > > val xyz = ... > > > > Then later if you want to override the getter you would do > > > > private val x = ... > > > > // getter > > > > def xyz = if(check_something) x else throw new IllegalStateException > > > > Then if you also want to add a setter you do > > > > private val x = ... > > > > def xyz = if(check_something) x else throw new IllegalStateException > > def xyz_=(x: Int) {xyz = x} > > > > Let's pick one of these and refactor towards it as we see code that > doesn't > > match. My vote would be for option 4. > > > > -Jay > > >
