On 26.10.2016 00:08, [email protected] wrote:
[...]
And just to interject the question the OP is probably going to ask:
Why should it matter whether it's an "extension" or not? Is it
documented that the methods available on a Delegate exclude what
Groovy has added to the class?
Jochen or someone other probably could give a better explanation, but myself, I
would dare a guess that the problem is that @Delegate is not a true redirector
(which I am still not quite sure is even possible to write Java-side!), but
(essentially) a request for the compiler to add redirection stubs for all the
known delegate methods.
The trick is that Groovy extensions are *not* known methods: they are not part
of the class API, instead, they are added metaclass-level. Thus, the @Delegate
AST does not know of them, and does not add appropriate stubs.
exactly. The same applies to the usage of categories and to methods
added to the meta class. The problem is reduced if we delegate to the
implementation of an interface and all the important logic is based on
the interface type. Because @Delegate per default implements the
interfaces of the delegates.
If you stayed completely at the dynamic side instead of using generated stubs
through @Delegate, it would work; on the other hand, it would not work from
Java code:
===
class Example {
Date when
def methodMissing(String name, args) {
when."$name"(*args)
}
}
def x = new Example(when: new Date())
println x.next() // works
===
It is not an either-or. You can do both, causing less load for
methodMissing and faster dispatch.
Finally, as for the presumed question whether the @Delegate AST _could_ find
the methods added through extensions... I am not entirely sure. I think it
could, but it might get a bit difficult and perhaps even sort of unreliable.
Definitely it would be problematic if called from Java.
Presuming the availability and usage of certain extension methods is
imho ok for the static compiler, but not for dynamic Groovy - not if you
expect a runtime added extension method to have influence
bye Jochen
