69 lines
2.0 KiB
Kotlin
69 lines
2.0 KiB
Kotlin
/*
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* Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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/*
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* C3 MRO tests for Multiple Inheritance
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*/
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import kotlinx.coroutines.test.runTest
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import net.sergeych.lyng.eval
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import kotlin.test.Test
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class MIC3MroTest {
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@Test
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fun diamondConstructorRunsSharedAncestorOnce() = runTest {
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eval(
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"""
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var topInit = 0
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class Top() {
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// increment module-scope counter in instance initializer; runs once per Top-subobject
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var tick = (topInit = topInit + 1)
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}
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class Left() : Top()
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class Right() : Top()
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class Bottom() : Left(), Right()
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val b = Bottom()
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assertEquals(1, topInit)
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""".trimIndent()
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)
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}
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@Test
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fun methodResolutionFollowsC3() = runTest {
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// For the classic diamond D(B,C), B and C derive from A; C3 should result in D -> B -> C -> A
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eval(
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"""
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class A() { fun common() { "A" } }
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class B() : A() { fun common() { "B" } }
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class C() : A() { fun common() { "C" } }
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class D() : B(), C()
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val d = D()
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// Unqualified must pick B.common() according to C3 when direct bases are (B, C)
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assertEquals("B", d.common())
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// Qualified disambiguation via casts still works
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assertEquals("C", (d as C).common())
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assertEquals("A", (d as A).common())
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""".trimIndent()
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)
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}
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}
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