kotlin bad

gistfile1.txt

Compiled from "Test.kt"
public final class com.darichey.test.TestKt {
  public static final void main();
    Code:
       0: iconst_2
       1: anewarray     #11                 // class java/lang/Integer
       4: dup
       5: iconst_0
       6: iconst_m1
       7: invokestatic  #15                 // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
      10: aastore
      11: dup
      12: iconst_1
      13: iconst_1
      14: invokestatic  #15                 // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
      17: aastore
      18: invokestatic  #21                 // Method kotlin/collections/CollectionsKt.listOf:([Ljava/lang/Object;)Ljava/util/List;
      21: astore_0
      22: aload_0
      23: checkcast     #23                 // class java/lang/Iterable
      26: astore_2
      27: iconst_0
      28: istore_3
      29: aload_2
      30: astore        4
      32: new           #25                 // class java/util/ArrayList
      35: dup
      36: aload_2
      37: bipush        10
      39: invokestatic  #29                 // Method kotlin/collections/CollectionsKt.collectionSizeOrDefault:(Ljava/lang/Iterable;I)I
      42: invokespecial #33                 // Method java/util/ArrayList."<init>":(I)V
      45: checkcast     #35                 // class java/util/Collection
      48: astore        5
      50: iconst_0
      51: istore        6
      53: aload         4
      55: invokeinterface #39,  1           // InterfaceMethod java/lang/Iterable.iterator:()Ljava/util/Iterator;
      60: astore        7
      62: aload         7
      64: invokeinterface #45,  1           // InterfaceMethod java/util/Iterator.hasNext:()Z
      69: ifeq          127
      72: aload         7
      74: invokeinterface #49,  1           // InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object;
      79: astore        8
      81: aload         5
      83: aload         8
      85: checkcast     #51                 // class java/lang/Number
      88: invokevirtual #55                 // Method java/lang/Number.intValue:()I
      91: istore        9
      93: astore        11
      95: iconst_0
      96: istore        10
      98: iload         9
     100: invokestatic  #59                 // Method foo:(I)Ljava/lang/String;
     103: dup
     104: ifnull        110
     107: goto          112
     110: pop
     111: aconst_null
     112: astore        12
     114: aload         11
     116: aload         12
     118: invokeinterface #63,  2           // InterfaceMethod java/util/Collection.add:(Ljava/lang/Object;)Z
     123: pop
     124: goto          62
     127: aload         5
     129: checkcast     #65                 // class java/util/List
     132: astore_1
     133: aload_1
     134: iconst_0
     135: invokeinterface #69,  2           // InterfaceMethod java/util/List.get:(I)Ljava/lang/Object;
     140: invokevirtual #73                 // Method java/lang/Object.toString:()Ljava/lang/String;
     143: astore_2
     144: iconst_0
     145: istore_3
     146: getstatic     #79                 // Field java/lang/System.out:Ljava/io/PrintStream;
     149: aload_2
     150: invokevirtual #85                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
     153: return

  public static void main(java.lang.String[]);
    Code:
       0: invokestatic  #9                  // Method main:()V
       3: return

  public static final java.lang.String foo(int);
    Code:
       0: iload_0
       1: ifge          8
       4: aconst_null
       5: goto          12
       8: iload_0
       9: invokestatic  #105                // Method java/lang/String.valueOf:(I)Ljava/lang/String;
      12: areturn
}

Test.kt

fun main() {
    val list = listOf(-1, 1)
    val newList: List<Any> = list.map {
        return@map foo(it) ?: return@map
    }

    println(newList[0].toString())
}

fun foo(i: Int): String? =
    if (i < 0) null else i.toString()