added Multiple Inheritance

lynglib/src/commonTest/kotlin/MIC3MroTest.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2025 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.
+ *
+ */
+
+/*
+ * C3 MRO tests for Multiple Inheritance
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+
+class MIC3MroTest {
+
+    @Test
+    fun diamondConstructorRunsSharedAncestorOnce() = runTest {
+        eval(
+            """
+            var topInit = 0
+
+            class Top() {
+                // increment module-scope counter in instance initializer; runs once per Top-subobject
+                var tick = (topInit = topInit + 1)
+            }
+
+            class Left() : Top()
+            class Right() : Top()
+            class Bottom() : Left(), Right()
+
+            val b = Bottom()
+            assertEquals(1, topInit)
+            """.trimIndent()
+        )
+    }
+
+    @Test
+    fun methodResolutionFollowsC3() = runTest {
+        // For the classic diamond D(B,C), B and C derive from A; C3 should result in D -> B -> C -> A
+        eval(
+            """
+            class A() { fun common() { "A" } }
+            class B() : A() { fun common() { "B" } }
+            class C() : A() { fun common() { "C" } }
+            class D() : B(), C()
+
+            val d = D()
+            // Unqualified must pick B.common() according to C3 when direct bases are (B, C)
+            assertEquals("B", d.common())
+            // Qualified disambiguation via casts still works
+            assertEquals("C", (d as C).common())
+            assertEquals("A", (d as A).common())
+            """.trimIndent()
+        )
+    }
+}