indexer fix

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/Obj.kt

@@ -646,6 +646,9 @@ open class Obj {
     }
 
     open suspend fun getAt(scope: Scope, index: Obj): Obj {
+        if (hasNonRootIndexerMember("getAt")) {
+            return invokeInstanceMethod(scope, "getAt", Arguments(index))
+        }
         if (index is ObjString) {
             return readField(scope, index.value).value
         }
@@ -655,6 +658,16 @@ open class Obj {
     suspend fun getAt(scope: Scope, index: Int): Obj = getAt(scope, ObjInt(index.toLong()))
 
     open suspend fun putAt(scope: Scope, index: Obj, newValue: Obj) {
+        when {
+            hasNonRootIndexerMember("putAt") -> {
+                invokeInstanceMethod(scope, "putAt", Arguments(index, newValue))
+                return
+            }
+            hasNonRootIndexerMember("setAt") -> {
+                invokeInstanceMethod(scope, "setAt", Arguments(index, newValue))
+                return
+            }
+        }
         if (index is ObjString) {
             writeField(scope, index.value, newValue)
             return
@@ -662,6 +675,17 @@ open class Obj {
         scope.raiseNotImplemented("indexing")
     }
 
+    private fun hasNonRootIndexerMember(name: String): Boolean {
+        for (cls in objClass.mro) {
+            if (cls.className == "Obj") break
+            val rec = cls.members[name] ?: cls.classScope?.objects?.get(name)
+            if (rec != null && !rec.isAbstract && rec.type != ObjRecord.Type.Delegated) {
+                return true
+            }
+        }
+        return false
+    }
+
     open suspend fun callOn(scope: Scope): Obj {
         scope.raiseNotImplemented()
     }

lynglib/src/commonTest/kotlin/TypesTest.kt

@@ -20,7 +20,6 @@ import net.sergeych.lyng.Script
 import net.sergeych.lyng.ScriptError
 import net.sergeych.lyng.eval
 import kotlin.test.Test
-import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertTrue
 
@@ -536,6 +535,24 @@ class TypesTest {
         """.trimIndent())
     }
 
+    @Test fun testIndexer() = runTest {
+        eval("""
+            class Greeter {
+                override fun getAt(name) = "Hello, %s!"(name)
+            }
+            assertEquals("Hello, Bob!",Greeter()["Bob"])
+            val g = Greeter()
+            assertEquals("Hello, Bob!",g["Bob"])
+            
+            // it should work with objects too:
+            object Polite {
+            override fun getAt(name) = "How do you do, %s?"(name)
+            }
+            
+            assertEquals("How do you do, Bob?",Polite["Bob"])
+            
+        """.trimIndent())
+    }
 //    @Test fun nonTrivialOperatorsTest() = runTest {
 //        val s = Script.newScope()
 //        s.eval("""