Hey guys I'm trying to convert an odd lambda expre...

# getting-started

[Arimil]

Hey guys I'm trying to convert an odd lambda expression from a gradle plugin to Kotlin:

project.getExtensions().configure(PublishingExtension.class, extension -> {
            extension.getPublications().registerFactory(MavenPublication.class, new MavenPublicationFactory(
                    dependencyMetaDataProvider,
                    instantiatorFactory.decorateLenient(),
                    fileResolver,
                    project.getPluginManager(),
                    project.getExtensions()));
            realizePublishingTasksLater(project, extension);
        });

However I'm having issues with the syntax for this in Kotlin.

[Arimil]

The auto conversion tries to convert to this:

project.extensions.configure(
            PublishingExtension::class.java,
            Action<PublishingExtension> { extension: PublishingExtension ->
                extension.publications.registerFactory<MavenPublication>(
                    MavenPublication::class.java,
                    MavenPublicationFactory(
                        dependencyMetaDataProvider,
                        instantiatorFactory.decorateLenient(),
                        fileResolver,
                        project.pluginManager,
                        project.extensions
                    )
                )
                realizePublishingTasksLater(project, extension)
            })

Which is unfortunately invalid syntax.

[Roukanken]

what's invalid about it? Look fine at first glance

[Arimil]

Type mismatch: inferred type is PublishingExtension!.(PublishingExtension) -> Unit but TypeVariable(T)!.() -> Unit was expected

[Arimil]

That's the compilation error, however I have no clue what it means.

[Roukanken]

ah, it wants a lambda of type T.() -> Unit instead of T.(T) -> Unit
Basically it tells you, it wants the extension parameter as this instead

[Roukanken]

project.extensions.configure(
            PublishingExtension::class.java,
            Action<PublishingExtension> { 
                publications.registerFactory<MavenPublication>(
                    MavenPublication::class.java,
                    MavenPublicationFactory(
                        dependencyMetaDataProvider,
                        instantiatorFactory.decorateLenient(),
                        fileResolver,
                        project.pluginManager,
                        project.extensions
                    )
                )
                realizePublishingTasksLater(project, this)
            })

something like this should be minimal change to get it working I think
(bunch of stuff is still extraneous tho)

[Arimil]

Thanks, I get it now.

[Roukanken]

project.extensions.configure<PublishingExtension> {
            publications.registerFactory<MavenPublication>(
                MavenPublication::class.java,
                MavenPublicationFactory(
                    dependencyMetaDataProvider,
                    instantiatorFactory.decorateLenient(),
                    fileResolver,
                    project.pluginManager,
                    project.extensions
                )
            )
            realizePublishingTasksLater(project, this)
        }

this should work too as configure should have reified version afaik

and registerFactory will likely have one too, look if it has it