From c88aea4655fb8396741dba4fa13a2315e30d14d2 Mon Sep 17 00:00:00 2001 From: Michael Williamson Date: Wed, 3 Jan 2024 22:21:36 +0000 Subject: Add subtyping between sum types --- .../typechecker/TypeCheckerIsSubTypeTests.java | 23 ++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'src/test/java') diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java index 580be580..d758cd96 100644 --- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java +++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java @@ -195,6 +195,29 @@ public class TypeCheckerIsSubTypeTests { assertThat(isSubType(sumType, variantType2, typeInfos), equalTo(false)); } + @Test + public void sumTypeIsSubtypeOfOtherSumtypeIfVariantsAreSubsetOfOtherVariants() { + var namespaceName = NamespaceName.of("Example", "Project"); + var sumType1 = Types.sum(namespaceName, "Sum1"); + var sumType2 = Types.sum(namespaceName, "Sum2"); + var variantType1 = Types.struct(namespaceName, "Variant1"); + var variantType2 = Types.struct(namespaceName, "Variant2"); + var variantType3 = Types.struct(namespaceName, "Variant3"); + var typeInfos = TypeInfos.EMPTY + .addSumTypeInfo(sumType1, new SumTypeInfo(P.orderedSet( + variantType1, + variantType2 + ))) + .addSumTypeInfo(sumType2, new SumTypeInfo(P.orderedSet( + variantType1, + variantType2, + variantType3 + ))); + + assertThat(isSubType(sumType1, sumType2, typeInfos), equalTo(true)); + assertThat(isSubType(sumType2, sumType1, typeInfos), equalTo(false)); + } + @Test public void variantWithoutTypeLevelArgIsSubTypeOfConstructedSumType() { var namespaceName = NamespaceName.of("Example", "Project"); -- cgit v1.2.3