Jan,
as always, I might be missing something of importance, but I believe a Closure
does not have a return type at all (or, more precisely, the return type of all
Closures is, by definition, Object).
After all, is there a way to define a closure which returns a non-object, say,
int? I think not.
All the best,
OC
> On 18. 1. 2021, at 9:55 AM, Jan Lukavský <je...@seznam.cz> wrote:
>
> Hi,
>
> resending this to dev@ (originally users@). Would anyone know if what I'm
> trying to achieve is possible? I think the compiler has enough information
> and (using either @TypeChecked or @CompileStatic) it should be possible to
> get the return type of Closure at runtime.
>
> Thanks for any comments,
>
> Jan
>
> On 1/12/21 10:36 AM, Jan Lukavský wrote:
>> Hi,
>>
>> I'm struggling with something I believe should be possible - when a Closure
>> is parsed at runtime, it should be possible to retrieve its generic return
>> type.
>>
>> I have the following (in Java):
>>
>> @Test
>> public void testClosureReturnTypeExtraction() {
>> String script = "def a = { 1L }";
>> Closure<?> closure = (Closure<?>) compile(script).run();
>> Class<?> returnType = retrieveReturnTypeFrom(closure); // how to
>> implement this??
>> assertEquals(Long.class, returnType);
>> }
>>
>> What I cannot figure out is how to extract the type information from the
>> generated closure. I believe the type information should be there (or at
>> least it should be possible to put it there). So far, my best attempt was,
>> that I got that the type argument is "V". :-)
>>
>> Any pointers would be appreciated.
>>
>> Cheers,
>>
>> Jan
>>
