From 0138badca3abaeca2ea40405cad3788c5048c36e Mon Sep 17 00:00:00 2001 From: Michael Williamson Date: Sun, 1 Oct 2023 19:57:15 +0100 Subject: Check variant is valid --- .../org/shedlang/compiler/typechecker/TypeChecker.java | 8 ++++++++ .../typechecker/errors/UnreachableWhenCaseError.java | 18 ++++++++++++++++++ 2 files changed, 26 insertions(+) create mode 100644 src/main/java/org/shedlang/compiler/typechecker/errors/UnreachableWhenCaseError.java (limited to 'src/main/java') diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java index 09a55c08..d38c5ac1 100644 --- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java +++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java @@ -1156,6 +1156,14 @@ public class TypeChecker { var expressionTypeInfo = context.sumTypeInfo(expressionType, untyped.source()); var variantTypes = expressionTypeInfo.variants(); + + for (var typedCase : typedCases) { + var caseType = typedCase.caseType().value(); + if (!variantTypes.contains(caseType)) { + throw new UnreachableWhenCaseError(caseType, typedCase.source()); + } + } + var handledVariantTypes = typedCases.stream() .map(typedCase -> typedCase.caseType().value()) .collect(Collectors.toSet()); diff --git a/src/main/java/org/shedlang/compiler/typechecker/errors/UnreachableWhenCaseError.java b/src/main/java/org/shedlang/compiler/typechecker/errors/UnreachableWhenCaseError.java new file mode 100644 index 00000000..803d22ea --- /dev/null +++ b/src/main/java/org/shedlang/compiler/typechecker/errors/UnreachableWhenCaseError.java @@ -0,0 +1,18 @@ +package org.shedlang.compiler.typechecker.errors; + +import org.shedlang.compiler.errors.SourceError; +import org.shedlang.compiler.sources.Source; +import org.shedlang.compiler.types.Type; + +public class UnreachableWhenCaseError extends SourceError { + private final Type caseType; + + public UnreachableWhenCaseError(Type caseType, Source source) { + super("The case for " + caseType.describe() + " is unreachable", source); + this.caseType = caseType; + } + + public Type caseType() { + return caseType; + } +} -- cgit v1.2.3