Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix: type checking of two union types #949

Merged
merged 1 commit into from
Mar 29, 2024
Merged

fix: type checking of two union types #949

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 8 additions & 6 deletions packages/safe-ds-lang/src/language/typing/safe-ds-type-checker.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,12 +50,14 @@ export class SafeDsTypeChecker {
* Checks whether {@link type} is a subtype of {@link other}.
*/
isSubtypeOf = (type: Type, other: Type, options: TypeCheckOptions = {}): boolean => {
// Handle base cases
if (type.equals(this.coreTypes.Nothing) || other.equals(this.coreTypes.AnyOrNull)) {
return true;
} else if (type === UnknownType || other === UnknownType) {
return false;
}

// Handle type parameter types
if (other instanceof TypeParameterType) {
if (type.isExplicitlyNullable && !other.isExplicitlyNullable) {
return false;
Expand All @@ -68,10 +70,16 @@ export class SafeDsTypeChecker {

const otherLowerBound = this.coreTypes.Nothing.withExplicitNullability(other.isExplicitlyNullable);
return this.isSubtypeOf(type, otherLowerBound, options);
}

// Handle union types
if (type instanceof UnionType) {
return type.types.every((it) => this.isSubtypeOf(it, other, options));
} else if (other instanceof UnionType) {
return other.types.some((it) => this.isSubtypeOf(type, it, options));
}

// Handle other cases
if (type instanceof CallableType) {
return this.callableTypeIsSubtypeOf(type, other, options);
} else if (type instanceof ClassType) {
Expand All @@ -88,8 +96,6 @@ export class SafeDsTypeChecker {
return this.staticTypeIsSubtypeOf(type, other, options);
} else if (type instanceof TypeParameterType) {
return this.typeParameterTypeIsSubtypeOf(type, other, options);
} else if (type instanceof UnionType) {
return this.unionTypeIsSubtypeOf(type, other, options);
} /* c8 ignore start */ else {
throw new Error(`Unexpected type: ${type.constructor.name}`);
} /* c8 ignore stop */
Expand Down Expand Up @@ -312,10 +318,6 @@ export class SafeDsTypeChecker {
return this.isSubtypeOf(upperBound, other, options);
}

private unionTypeIsSubtypeOf(type: UnionType, other: Type, options: TypeCheckOptions): boolean {
return type.types.every((it) => this.isSubtypeOf(it, other, options));
}

// -----------------------------------------------------------------------------------------------------------------
// Special cases
// -----------------------------------------------------------------------------------------------------------------
Expand Down
20 changes: 17 additions & 3 deletions packages/safe-ds-lang/tests/language/typing/type checker/isSubOrSupertypeOf.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -59,8 +59,6 @@ const basic = async (): Promise<IsSubOrSupertypeOfTest[]> => {
class Class2() sub Class1
class Class3

class Class4

enum Enum1 {
Variant1(p: Int)
Variant2
Expand Down Expand Up @@ -654,7 +652,23 @@ const basic = async (): Promise<IsSubOrSupertypeOfTest[]> => {
type2: enumType1,
expected: false,
},
// Union type to X
// Union type to union type
{
type1: factory.createUnionType(classType1, classType2),
type2: factory.createUnionType(classType1, classType2),
expected: true,
},
{
type1: factory.createUnionType(classType1, classType2),
type2: factory.createUnionType(classType1, classType3),
expected: true,
},
{
type1: factory.createUnionType(classType1, classType3),
type2: factory.createUnionType(classType1, classType2),
expected: false,
},
// Union type to other
{
type1: factory.createUnionType(),
type2: classType1,
Expand Down