feat: error if type parameter is used in nested named type declaration

Safe-DS · Nov 10, 2023 · 354c00d · 354c00d
1 parent 4ce4fd1
commit 354c00d
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Showing 3 changed files with 67 additions and 3 deletions.
diff --git a/packages/safe-ds-lang/src/language/validation/other/declarations/typeParameters.ts b/packages/safe-ds-lang/src/language/validation/other/declarations/typeParameters.ts
@@ -1,13 +1,16 @@
+import { findLocalReferences, getContainerOfType, hasContainerOfType, ValidationAcceptor } from 'langium';
 import {
     isSdsCallable,
     isSdsClass,
+    isSdsDeclaration,
+    isSdsNamedTypeDeclaration,
     isSdsParameterList,
     isSdsUnionType,
     SdsTypeParameter,
 } from '../../../generated/ast.js';
-import { findLocalReferences, getContainerOfType, hasContainerOfType, ValidationAcceptor } from 'langium';
 
 export const CODE_TYPE_PARAMETER_INSUFFICIENT_CONTEXT = 'type-parameter/insufficient-context';
+export const CODE_TYPE_PARAMETER_USAGE = 'type-parameter/usage';
 
 export const typeParameterMustHaveSufficientContext = (node: SdsTypeParameter, accept: ValidationAcceptor) => {
     const containingCallable = getContainerOfType(node, isSdsCallable);
@@ -45,3 +48,29 @@ export const typeParameterMustHaveSufficientContext = (node: SdsTypeParameter, a
         });
     }
 };
+
+export const typeParameterMustNotBeUsedInNestedNamedTypeDeclarations = (
+    node: SdsTypeParameter,
+    accept: ValidationAcceptor,
+) => {
+    // Only classes can have nested named type declarations
+    const declarationWithTypeParameter = getContainerOfType(node.$container, isSdsDeclaration);
+    if (!isSdsClass(declarationWithTypeParameter)) {
+        return;
+    }
+
+    findLocalReferences(node).forEach((it) => {
+        const reference = it.$refNode?.astNode;
+        const containingNamedTypeDeclaration = getContainerOfType(reference, isSdsNamedTypeDeclaration);
+        if (
+            reference &&
+            containingNamedTypeDeclaration &&
+            containingNamedTypeDeclaration !== declarationWithTypeParameter
+        ) {
+            accept('error', 'Type parameters cannot be used in nested named type declarations.', {
+                node: reference,
+                code: CODE_TYPE_PARAMETER_USAGE,
+            });
+        }
+    });
+};
diff --git a/packages/safe-ds-lang/src/language/validation/safe-ds-validator.ts b/packages/safe-ds-lang/src/language/validation/safe-ds-validator.ts
@@ -72,7 +72,10 @@ import {
     segmentShouldBeUsed,
 } from './other/declarations/segments.js';
 import { typeParameterConstraintLeftOperandMustBeOwnTypeParameter } from './other/declarations/typeParameterConstraints.js';
-import { typeParameterMustHaveSufficientContext } from './other/declarations/typeParameters.js';
+import {
+    typeParameterMustHaveSufficientContext,
+    typeParameterMustNotBeUsedInNestedNamedTypeDeclarations,
+} from './other/declarations/typeParameters.js';
 import { callArgumentsMustBeConstantIfParameterIsConstant } from './other/expressions/calls.js';
 import { divisionDivisorMustNotBeZero } from './other/expressions/infixOperations.js';
 import {
@@ -309,7 +312,10 @@ export const registerValidationChecks = function (services: SafeDsServices) {
             segmentShouldBeUsed(services),
         ],
         SdsTemplateString: [templateStringMustHaveExpressionBetweenTwoStringParts],
-        SdsTypeParameter: [typeParameterMustHaveSufficientContext],
+        SdsTypeParameter: [
+            typeParameterMustHaveSufficientContext,
+            typeParameterMustNotBeUsedInNestedNamedTypeDeclarations,
+        ],
         SdsTypeParameterConstraint: [typeParameterConstraintLeftOperandMustBeOwnTypeParameter],
         SdsTypeParameterList: [typeParameterListShouldNotBeEmpty],
         SdsUnionType: [

diff --git a/...-ds-lang/tests/resources/validation/other/declarations/type parameters/usage/main.sdstest b/...-ds-lang/tests/resources/validation/other/declarations/type parameters/usage/main.sdstest
@@ -0,0 +1,29 @@
+package tests.validation.other.declarations.typeParameters.usage
+
+// $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+class MyClass<T>(p: »T«) {
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    attr a: »T«
+
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    fun f<S>(p1: »T«, p2: »S«) -> (r1: »T«, r2: »S«)
+
+    // $TEST$ error "Type parameters cannot be used in nested named type declarations."
+    // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+    class MyInnerClass<S>(p1: »T«, p2: »S«) {
+        // $TEST$ error "Type parameters cannot be used in nested named type declarations."
+        attr a: »T«
+
+        // $TEST$ error "Type parameters cannot be used in nested named type declarations."
+        fun f(p: »T«)
+    }
+
+    enum MyInnerEnum {
+        // $TEST$ error "Type parameters cannot be used in nested named type declarations."
+        // $TEST$ no error "Type parameters cannot be used in nested named type declarations."
+        MyEnumVariant<S>(p1: »T«, p2: »S«)
+    }
+}