How do I package extension functions in a library jar?

I have a set of extension functions that I would like to package into a jar and include in a project, but I can't seem to assess the extension functions from the jar. I can access non-extension functions from the same jar.

For example if I create a project in Idea including the following file, and build the jar.

package mypackagename.swtbuilder

import org.eclipse.swt.SWT
import org.eclipse.swt.widgets.*

fun myFun() {
    println("here")
}


fun Composite.tree(treeStyle: Int = SWT.NONE, init: Tree.() -> Unit): Tree {
    val treeWidget = Tree(this, treeStyle)
    treeWidget.init()
    return treeWidget
}

Then include the jar as a dependency in another project using something like this in the build.gradle file.

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    compile "org.eclipse.swt:org.eclipse.swt.gtk.linux.x86_64:4.5.2"
    compile files('/home/john/development/swt-builder/build/libs/swt-builder-1.0-SNAPSHOT.jar')

}

I can use myFun in the new project, but all the extension functions are unresolved.

import mypackagename.swtbuilder.myFun  // this import works
import mypackagename.swtbuilder.tree  // this import is "grayed out"

fun main(args: Array<String>) {

    val display = Display()
    myFun()  // this function call works
    val myTree = tree {    // tree is un-resolved
    }
}

What do I need to do to make the extension functions visible?

Solution

Silly mistake, the extension functions are visible, they just need to be called in the context of object they are extensions of. In this case a Shell which is a subclass of Composite. I had all this working fine when the extensions and the main were in the same project. I was trying to make the extensions a separate library and got ahead of myself trying to make sure they were imported properly.

fun main(args: Array<String>) {
    val display = Display()
    val myShell = shell {
        tree { }
    }
    myShell.open()
    while (!myShell.isDisposed) {
        if (!display.readAndDispatch()) display.sleep()
    }
    display.dispose()
}