added Multiple Inheritance

2025-11-17 00:28:07 +01:00
1 parent 882df67909
commit aeeec2d417
@@ -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()
+        )
+    }
+}
@@ -0,0 +1,105 @@
+/*
+ * 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.
+ *
+ */
+
+/*
+ * Diagnostics tests for Multiple Inheritance (MI)
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+import kotlin.test.assertFails
+import kotlin.test.assertTrue
+
+class MIDiagnosticsTest {
+
+    @Test
+    fun missingMemberIncludesLinearizationAndHint() = runTest {
+        val ex = assertFails {
+            eval(
+                """
+                class Foo(val a) { fun runA() { "ResultA:" + a } }
+                class Bar(val b) { fun runB() { "ResultB:" + b } }
+                class FooBar(a,b) : Foo(a), Bar(b) { }
+                val fb = FooBar(1,2)
+                fb.qux()
+                """.trimIndent()
+            )
+        }
+        val msg = ex.message ?: ""
+        assertTrue(msg.contains("no such member: qux"), "must mention missing member name")
+        assertTrue(msg.contains("FooBar"), "must mention receiver class name")
+        assertTrue(msg.contains("Considered order:"), "must include linearization header")
+        assertTrue(msg.contains("FooBar") && msg.contains("Foo") && msg.contains("Bar"), "must list classes in order")
+        assertTrue(msg.contains("this@") || msg.contains("(obj as"), "must suggest qualification or cast")
+    }
+
+    @Test
+    fun missingFieldIncludesLinearization() = runTest {
+        val ex = assertFails {
+            eval(
+                """
+                class Foo(val a) { var tag = "F" }
+                class Bar(val b) { var tag = "B" }
+                class FooBar(a,b) : Foo(a), Bar(b) { }
+                val fb = FooBar(1,2)
+                fb.unknownField
+                """.trimIndent()
+            )
+        }
+        val msg = ex.message ?: ""
+        assertTrue(msg.contains("no such field: unknownField"))
+        assertTrue(msg.contains("FooBar"))
+        assertTrue(msg.contains("Considered order:"))
+    }
+
+    @Test
+    fun invalidQualifiedThisReportsAncestorError() = runTest {
+        assertFails {
+            eval(
+                """
+                class Foo() { fun f() { "F" } }
+                class Bar() { fun g() { "G" } }
+                class Baz() : Foo() {
+                    fun bad() { this@Bar.g() }
+                }
+                val b = Baz()
+                b.bad()
+                """.trimIndent()
+            )
+        }
+    }
+
+    @Test
+    fun castFailureMentionsActualAndTargetTypes() = runTest {
+        val ex = assertFails {
+            eval(
+                """
+                class Foo() { }
+                class Bar() { }
+                val b = Bar()
+                (b as Foo)
+                """.trimIndent()
+            )
+        }
+        val msg = ex.message ?: ""
+        // message like: Cannot cast Bar to Foo (be tolerant across targets)
+        val lower = msg.lowercase()
+        assertTrue(lower.contains("cast"), "message should mention cast")
+        assertTrue(msg.contains("Bar") || msg.contains("Foo"), "should mention at least one of the types")
+    }
+}
@@ -0,0 +1,98 @@
+/*
+ * 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.
+ *
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+
+class MIQualifiedDispatchTest {
+
+    @Test
+    fun testQualifiedMethodResolution() = runTest {
+        eval(
+            """
+            class Foo(val a) {
+                fun common() { "A" }
+                fun runA() { "ResultA:" + a }
+            }
+
+            class Bar(val b) {
+                fun common() { "B" }
+                fun runB() { "ResultB:" + b }
+            }
+
+            class FooBar(a,b) : Foo(a), Bar(b) { }
+
+            val fb = FooBar(1,2)
+
+            // unqualified picks leftmost base
+            assertEquals("A", fb.common())
+
+            // cast-based disambiguation
+            assertEquals("B", (fb as Bar).common())
+            assertEquals("A", (fb as Foo).common())
+
+            // Note: wrappers using this@Type inside FooBar body will be validated later
+            // when class-body method registration is finalized.
+            """.trimIndent()
+        )
+    }
+
+    @Test
+    fun testQualifiedFieldReadWrite() = runTest {
+        eval(
+            """
+            class Foo(val a) { var tag = "F" }
+            class Bar(val b) { var tag = "B" }
+            class FooBar(a,b) : Foo(a), Bar(b) { }
+
+            val fb = FooBar(1,2)
+            // unqualified resolves to leftmost base
+            assertEquals("F", fb.tag)
+            // qualified reads via casts
+            assertEquals("F", (fb as Foo).tag)
+            assertEquals("B", (fb as Bar).tag)
+
+            // unqualified write updates leftmost base
+            fb.tag = "X"
+            assertEquals("X", fb.tag)
+            assertEquals("X", (fb as Foo).tag)
+            assertEquals("B", (fb as Bar).tag)
+
+            // qualified write via cast targets Bar
+            (fb as Bar).tag = "Y"
+            assertEquals("X", (fb as Foo).tag)
+            assertEquals("Y", (fb as Bar).tag)
+            """.trimIndent()
+        )
+    }
+
+    @Test
+    fun testCastsAndSafeCall() = runTest {
+        eval(
+            """
+            class Foo(val a) { fun runA() { "ResultA:" + a } }
+            class Bar(val b) { fun runB() { "ResultB:" + b } }
+            class Buzz : Bar(3)
+            val buzz = Buzz()
+            assertEquals("ResultB:3", buzz.runB())
+            assertEquals("ResultB:3", (buzz as? Bar)?.runB())
+            assertEquals(null, (buzz as? Foo)?.runA())
+            """.trimIndent()
+        )
+    }
+}
@@ -0,0 +1,75 @@
+/*
+ * 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.
+ *
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+import kotlin.test.assertFails
+
+class MIVisibilityTest {
+
+    @Test
+    fun privateMethodNotVisibleInSubclass() = runTest {
+        val code = """
+            class Foo() {
+                private fun secret() { "S" }
+            }
+            class Bar() : Foo() {
+                fun trySecret() { this@Foo.secret() }
+            }
+            val b = Bar()
+            // calling a wrapper that tries to access Foo.secret must fail
+            b.trySecret()
+        """.trimIndent()
+        assertFails { eval(code) }
+    }
+
+    @Test
+    fun protectedMethodNotVisibleFromUnrelatedEvenViaCast() = runTest {
+        val code = """
+            class Foo() { protected fun prot() { "P" } }
+            class Bar() : Foo() { }
+            val b = Bar()
+            // Unrelated context tries to call through cast — should fail
+            (b as Foo).prot()
+        """.trimIndent()
+        assertFails { eval(code) }
+    }
+
+    @Test
+    fun privateFieldNotVisibleInSubclass() = runTest {
+        val code = """
+            class Foo() { private val x = "X" }
+            class Bar() : Foo() { fun getX() { this@Foo.x } }
+            val b = Bar()
+            b.getX()
+        """.trimIndent()
+        assertFails { eval(code) }
+    }
+
+    @Test
+    fun protectedFieldNotVisibleFromUnrelatedEvenViaCast() = runTest {
+        // Not allowed from unrelated, even via cast
+        val code = """
+            class Foo() { protected val y = "Y" }
+            class Bar() : Foo() { }
+            val b = Bar()
+            (b as Foo).y
+        """.trimIndent()
+        assertFails { eval(code) }
+    }
+}
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ *
+ */
+
+/*
+ * Focused regression test for local variable visibility across suspension inside withLock { }
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+
+class ParallelLocalScopeTest {
+
+    @Test
+    fun localsSurviveSuspensionInsideWithLock() = runTest {
+        // Minimal reproduction of the pattern used in ScriptTest.testParallels2
+        eval(
+            """
+            class AtomicCounter {
+                private val m = Mutex()
+                private var counter = 0
+
+                fun increment() {
+                    m.withLock {
+                        val a = counter
+                        delay(1)
+                        counter = a + 1
+                    }
+                }
+
+                fun getCounter() { counter }
+            }
+
+            val ac = AtomicCounter()
+            // Single-threaded increments should work if locals survive after delay
+            for (i in 1..3) ac.increment()
+            assertEquals(3, ac.getCounter())
+            """.trimIndent()
+        )
+    }
+}
@@ -0,0 +1,154 @@
+/*
+ * 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.
+ *
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import kotlin.test.Test
+
+/*
+ * 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.
+ *
+ */
+
+class TestInheritance {
+
+    @Test
+    fun testInheritanceSpecification() = runTest { 
+        eval("""
+        // Multiple inheritance specification test (spec only, parser/interpreter TBD)
+
+        // Parent A: exposes a val and a var, and a method with a name that collides with Bar.common()
+        class Foo(val a) {
+    var tag = "F"
+
+    fun runA() {
+        "ResultA:" + a
+    }
+
+    fun common() {
+        "CommonA"
+    }
+
+    // this can only be called from Foo (not from subclasses):
+    private fun privateInFoo() {
+    }
+
+    // this can be called from Foo and any subclass (including MI subclasses):
+    protected fun protectedInFoo() {
+    }
+}
+
+// Parent B: also exposes a val and a var with the same name to test field inheritance and conflict rules
+class Bar(val b) {
+    var tag = "B"
+
+    fun runB() {
+        "ResultB:" + b
+    }
+
+    fun common() {
+        "CommonB"
+    }
+}
+
+// With multiple inheritance, base constructors are called in the order of declaration,
+// and each ancestor is initialized at most once (diamonds are de-duplicated):
+class FooBar(a, b) : Foo(a), Bar(b) {
+
+    // Ambiguous method name "common" can be disambiguated:
+    fun commonFromFoo() {
+        // explicit qualification by ancestor type:
+        this@Foo.common()
+        // or by cast:
+        (this as Foo).common()
+    }
+
+    fun commonFromBar() {
+        this@Bar.common()
+        (this as Bar).common()
+    }
+
+    // Accessing inherited fields (val/var) respects the same resolution rules:
+    fun tagFromFoo() { this@Foo.tag }
+    fun tagFromBar() { this@Bar.tag }
+}
+
+val fb = FooBar(1, 2)
+
+// Methods with distinct names from different bases work:
+assertEquals("ResultA:1", fb.runA())
+assertEquals("ResultB:2", fb.runB())
+
+// If we call an ambiguous method unqualified, the first in MRO (leftmost base) is used:
+assertEquals("CommonA", fb.common())
+
+// We can call a specific one via explicit qualification or cast:
+assertEquals("CommonB", (fb as Bar).common())
+assertEquals("CommonA", (fb as Foo).common())
+
+// Or again via explicit casts (wrappers may be validated separately):
+assertEquals("CommonB", (fb as Bar).common())
+assertEquals("CommonA", (fb as Foo).common())
+
+// Inheriting val/var:
+// - Reading an ambiguous var/val selects the first along MRO (Foo.tag initially):
+assertEquals("F", fb.tag)
+// - Qualified access returns the chosen ancestor’s member:
+assertEquals("F", (fb as Foo).tag)
+assertEquals("B", (fb as Bar).tag)
+
+// - Writing an ambiguous var writes to the same selected member (first in MRO):
+fb.tag = "X"
+assertEquals("X", fb.tag)              // unqualified resolves to Foo.tag
+assertEquals("X", (fb as Foo).tag)     // Foo.tag updated
+assertEquals("B", (fb as Bar).tag)     // Bar.tag unchanged
+
+// - Qualified write via cast updates the specific ancestor’s storage:
+(fb as Bar).tag = "Y"
+assertEquals("X", (fb as Foo).tag)
+assertEquals("Y", (fb as Bar).tag)
+
+// A simple single-inheritance subclass still works:
+class Buzz : Bar(3)
+val buzz = Buzz()
+
+assertEquals("ResultB:3", buzz.runB())
+
+// Optional cast returns null if cast is not possible; use safe-call with it:
+assertEquals("ResultB:3", (buzz as? Bar)?.runB())
+assertEquals(null, (buzz as? Foo)?.runA())
+
+// Visibility (spec only):
+// - Foo.privateInFoo() is accessible only inside Foo body; even FooBar cannot call it,
+//   including with this@Foo or casts. Attempting to do so must be a compile-time error.
+// - Foo.protectedInFoo() is accessible inside Foo and any subclass bodies (including FooBar),
+//   but not from unrelated classes/instances.
+        """.trimIndent())
+    } 
+}