Description Sebastien Diot 2014-07-28 06:26:57 EDT

The following small test program gives me unexpected results when compiling:

    package test

    import java.util.HashMap
    import java.util.Map
    import org.junit.Test

    import static org.junit.Assert.*

    class MapTest {
        @Test
        public def void testCreation() {
            val map = new HashMap<String,Long>()
            val one = "one"
            map.put(one, 1L)
            val esa = map.entrySet.toArray(<Map.Entry>newArrayOfSize(1))
            assertNotNull("map.entrySet.toArray", esa)
            assertEquals("map.entrySet.toArray.length", 1, esa.length)
            // esa0 is an Object, but should be a Map.Entry!
            val esa0 = esa.get(0)
            assertNotNull("map.entrySet.toArray[0]", esa0)
    //        assertEquals("map.entrySet.toArray[0].key", one, esa0.key)
    //        assertEquals("map.entrySet.toArray[0].value", 1L, esa0.value)
        }
    }


The problem is esa; is should be typed as a Map.Entry, but isn't. And because of that, the last two lines of the test method do not compile.
The line "val esa0 = esa.get(0)" is compiled to:

    final Object esa0 = ((List<Map.Entry>)Conversions.doWrapArray(esa)).get(0);


I am also surprised that <array>.get(x) *wraps the array in a List*. Until now, I was assuming get(int) and set(int) were simply mapped to array[int]; this could result in highly inefficient code...