[jira] [Commented] (GROOVY-7789) ClosureParams type inference compilation error when wrapping closure with object

["Eric Milles (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/GROOVY-7789?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17433849#comment-17433849 ] 

Eric Milles commented on GROOVY-7789:
-------------------------------------

{{wrap}} returns a raw type {{A}} regardless of what "IN" can be determined to be.  There is no actual type witness for "IN".  One can be supplied like this:  {{def a_of_list = this.<List>wrap \{ i -> i.size() \};}} -- I'm assuming {{def <IN> A<IN> wrap(...)}}

In the case where an explicit type argument is supplied to the method call, Groovy 2.5 does not properly propagate the closure param type to the variable expression "i" in "i.size()".

{code:groovy}
import groovy.transform.stc.*

class A<T> {
  Closure c
  A(@ClosureParams(value=FromString, options='T') Closure c) {
    this.c = c
  }
  def call(T param) {
    c.call(param)
  }
}

def <U> A<U> wrap(@ClosureParams(value=FromString, options='U') Closure c) {
    new A<U>(c)
}

@groovy.transform.CompileStatic
def test7789() {
  def a_of_list = this.<List>wrap { i -> i.size(); } // STC error in Groovy 2.5: Cannot find matching method Object#size()
  def x = a_of_list.call([])
}
{code}

> ClosureParams type inference compilation error when wrapping closure with object
> --------------------------------------------------------------------------------
>
>                 Key: GROOVY-7789
>                 URL: https://issues.apache.org/jira/browse/GROOVY-7789
>             Project: Groovy
>          Issue Type: Bug
>          Components: Static compilation
>    Affects Versions: 2.4.6
>            Reporter: Krzysztof Białek
>            Priority: Major
>
> The following code does not compile:
> {code}
> import groovy.transform.*
> import groovy.transform.stc.*
> @CompileStatic
> class Test {
>     class A<IN> {
>         Closure c
>         A(@ClosureParams(value = FromString, options = 'IN') Closure c) {
>             this.c = c
>         }
>         void call(IN param) {
>             c.call(param)
>         }
>     }
>     def <IN> A wrap(@ClosureParams(value = FromString, options = 'IN') Closure c) {
>         new A<IN>(c)
>     }
>     def test() {
>         (wrap { i -> i.size() }).call([])
>     }
> }
> {code}
> Compilation error:
> {code}
> org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
> /tmp/groovy-2.4.6/test.groovy: 25: [Static type checking] - Cannot find matching method java.lang.Object#size(). Please check if the declared type is right and if the method exists.
>  @ line 24, column 22.
>            (wrap { i -> i.size() }).call([])
> {code}
> I'd expect 'i' being infered as java.util.List
> Explicit this.<List>wrap does not help neither



--
This message was sent by Atlassian Jira
(v8.3.4#803005)