Scala Language Dynamic Invocation Field Accesses
Example
This:
class Foo extends Dynamic {
// Expressions are only rewritten to use Dynamic if they are not already valid
// Therefore foo.realField will not use select/updateDynamic
var realField: Int = 5
// Called for expressions of the type foo.field
def selectDynamic(fieldName: String) = ???
def updateDynamic(fieldName: String)(value: Int) = ???
}
allows for simple access to fields:
val foo: Foo = ???
foo.realField // Does NOT use Dynamic; accesses the actual field
foo.realField = 10 // Actual field access here too
foo.unrealField // Becomes foo.selectDynamic(unrealField)
foo.field = 10 // Becomes foo.updateDynamic("field")(10)
foo.field = "10" // Does not compile; "10" is not an Int.
foo.x() // Does not compile; Foo does not define applyDynamic, which is used for methods.
foo.x.apply() // DOES compile, as Nothing is a subtype of () => Any
// Remember, the compiler is still doing static type checks, it just has one more way to
// "recover" and rewrite otherwise invalid code now.
