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by yummyfajitas 4532 days ago
Scala has value types.

    case class MyNewType(x: String) extends AnyVal
What do you want to do that that isn't sufficient for?
1 comments
kasey_junk 4532 days ago
AnyVal's would probably be sufficient except for the following: - Instantiation of the MyNewType happens all the time and is not obvious from inspection of the code (generics, use as another type if we implement a trait, etc). - If we want to call any of the methods on the wrapped type we have to call directly to the wrapped type violating Demeter. - Verbosity.
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yummyfajitas 4532 days ago
If we want to call any of the methods on the wrapped type we have to call directly to the wrapped type violating Demeter.

You can also use tagged types:

http://eed3si9n.com/learning-scalaz/Tagged+type.html

But most of the methods will untag the type. I.e., ("foo" @@ ValidJsonString).substring(3,7) will be a String, not a String @@ ValidJsonString.

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