fixed some exception catching problems on wasm target

lynglib/src/androidMain/kotlin/net/sergeych/lyng/obj/ObjListBoundsGuardAndroid.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal actual fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String? = null

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/CmdRuntime.kt

@@ -3663,7 +3663,11 @@ class CmdGetIndex(
         val target = frame.storedSlotObj(targetSlot)
         val index = frame.storedSlotObj(indexSlot)
         if (target is ObjList && target::class == ObjList::class && index is ObjInt) {
-            frame.storeObjResult(dst, target.getObjAtFast(index.toInt()))
+            val i = index.toInt()
+            objListBoundsViolationMessageOrNull(target.sizeFast(), i)?.let {
+                frame.ensureScope().raiseIndexOutOfBounds(it)
+            }
+            frame.storeObjResult(dst, target.getObjAtFast(i))
             return
         }
         val result = target.getAt(frame.ensureScope(), index)
@@ -3682,7 +3686,11 @@ class CmdSetIndex(
         val index = frame.storedSlotObj(indexSlot)
         val value = frame.slotToObj(valueSlot)
         if (target is ObjList && target::class == ObjList::class && index is ObjInt) {
-            target.setObjAtFast(index.toInt(), value)
+            val i = index.toInt()
+            objListBoundsViolationMessageOrNull(target.sizeFast(), i)?.let {
+                frame.ensureScope().raiseIndexOutOfBounds(it)
+            }
+            target.setObjAtFast(i, value)
             return
         }
         target.putAt(frame.ensureScope(), index, value)
@@ -3699,6 +3707,9 @@ class CmdGetIndexInt(
         val target = frame.storedSlotObj(targetSlot)
         val index = frame.getInt(indexSlot).toInt()
         if (target is ObjList && target::class == ObjList::class) {
+            objListBoundsViolationMessageOrNull(target.sizeFast(), index)?.let {
+                frame.ensureScope().raiseIndexOutOfBounds(it)
+            }
             target.getIntAtFast(index)?.let {
                 frame.setInt(dst, it)
                 return
@@ -3722,6 +3733,9 @@ class CmdSetIndexInt(
         val target = frame.storedSlotObj(targetSlot)
         val index = frame.getInt(indexSlot).toInt()
         if (target is ObjList && target::class == ObjList::class) {
+            objListBoundsViolationMessageOrNull(target.sizeFast(), index)?.let {
+                frame.ensureScope().raiseIndexOutOfBounds(it)
+            }
             target.setIntAtFast(index, frame.getInt(valueSlot))
             return
         }

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

@@ -171,7 +171,9 @@ open class ObjList(initialList: MutableList<Obj> = mutableListOf()) : Obj() {
     override suspend fun getAt(scope: Scope, index: Obj): Obj {
         return when (index) {
             is ObjInt -> {
-                getObjAtFast(index.toInt())
+                val i = index.toInt()
+                objListBoundsViolationMessageOrNull(sizeFast(), i)?.let { scope.raiseIndexOutOfBounds(it) }
+                getObjAtFast(i)
             }
 
             is ObjRange -> {
@@ -209,7 +211,9 @@ open class ObjList(initialList: MutableList<Obj> = mutableListOf()) : Obj() {
     }
 
     open override suspend fun putAt(scope: Scope, index: Obj, newValue: Obj) {
-        setObjAtFast(index.toInt(), newValue)
+        val i = index.toInt()
+        objListBoundsViolationMessageOrNull(sizeFast(), i)?.let { scope.raiseIndexOutOfBounds(it) }
+        setObjAtFast(i, newValue)
     }
 
     override suspend fun compareTo(scope: Scope, other: Obj): Int {

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

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal expect fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String?

lynglib/src/commonTest/kotlin/StdlibTest.kt

@@ -16,8 +16,16 @@
  */
 
 import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.Script
 import net.sergeych.lyng.eval
+import net.sergeych.lyng.evalNamed
+import net.sergeych.lyng.obj.ObjException
+import net.sergeych.lyng.obj.ObjInstance
+import net.sergeych.lyng.obj.getLyngExceptionMessage
+import net.sergeych.lyng.obj.getLyngExceptionStackTrace
 import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
 
 class StdlibTest {
     @Test
@@ -373,4 +381,59 @@ class StdlibTest {
             """.trimIndent()
         )
     }
+
+    @Test
+    fun testErrorCatching() = runTest {
+        val error = evalNamed("testErrorCatching", """
+            val src = [1,2,3]
+            val d = launch {
+                try {
+                    for( i in 0..3 ) src[i]
+                } catch(e) {
+                   e
+                }
+            }
+            d.await()
+        """.trimIndent()
+        )
+
+        val scope = when (error) {
+            is ObjException -> error.scope
+            is ObjInstance -> error.instanceScope
+            else -> Script.newScope()
+        }
+        val trace = error.getLyngExceptionStackTrace(scope)
+        val renderedTrace = trace.list.map { it.toString(scope).value }
+
+        assertEquals("Index 3 out of bounds for length 3", error.getLyngExceptionMessage(scope))
+        assertTrue(trace.list.size >= 2, "expected at least await and coroutine frames, got ${trace.list.size}")
+        assertTrue(
+            renderedTrace.all { it.contains("testErrorCatching:") },
+            "unexpected trace entries: $renderedTrace"
+        )
+        assertTrue(
+            renderedTrace.any { it.contains("launch") || it.contains("src[i]") },
+            "trace should include the coroutine body: $renderedTrace"
+        )
+        assertTrue(
+            renderedTrace.any { it.contains("d.await()") },
+            "trace should include await site: $renderedTrace"
+        )
+    }
+
+    @Test
+    fun testCatchToIt() = runTest {
+        eval("""
+            var x = 0
+            try {
+                throw "msg1"
+                x = 1
+            }
+            catch {
+                assert(it.message == "msg1")
+                x = 2
+            }
+            assertEquals(2, x)
+        """.trimIndent())
+    }
 }

lynglib/src/jsMain/kotlin/net/sergeych/lyng/obj/ObjListBoundsGuardJs.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal actual fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String? =
+    if (index < 0 || index >= size) "Index $index out of bounds for length $size" else null

lynglib/src/jvmMain/kotlin/net/sergeych/lyng/obj/ObjListBoundsGuardJvm.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal actual fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String? = null

lynglib/src/nativeMain/kotlin/net/sergeych/lyng/obj/ObjListBoundsGuardNative.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal actual fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String? = null

lynglib/src/wasmJsMain/kotlin/net/sergeych/lyng/obj/ObjListBoundsGuardWasmJs.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+internal actual fun objListBoundsViolationMessageOrNull(size: Int, index: Int): String? =
+    if (index < 0 || index >= size) "Index $index out of bounds for length $size" else null