From 81fb48d5c12efb1221dc21a7abd53b4b03bb1957 Mon Sep 17 00:00:00 2001
From: Lars Reimann <mail@larsreimann.com>
Date: Fri, 10 Nov 2023 22:16:41 +0100
Subject: [PATCH] feat: mark constraint lists as experimental

---
 .../language/validation/experimentalLanguageFeatures.ts  | 9 +++++++++
 .../src/language/validation/safe-ds-validator.ts         | 3 ++-
 .../constraint lists/main.sdstest                        | 4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 packages/safe-ds-lang/tests/resources/validation/experimental language feature/constraint lists/main.sdstest

diff --git a/packages/safe-ds-lang/src/language/validation/experimentalLanguageFeatures.ts b/packages/safe-ds-lang/src/language/validation/experimentalLanguageFeatures.ts
index 94ecfe389..d0ba47cc6 100644
--- a/packages/safe-ds-lang/src/language/validation/experimentalLanguageFeatures.ts
+++ b/packages/safe-ds-lang/src/language/validation/experimentalLanguageFeatures.ts
@@ -2,6 +2,7 @@ import {
     isSdsIndexedAccess,
     isSdsMap,
     isSdsUnionType,
+    SdsConstraintList,
     SdsIndexedAccess,
     SdsLiteralType,
     SdsMap,
@@ -11,6 +12,14 @@ import { hasContainerOfType, ValidationAcceptor } from 'langium';
 
 export const CODE_EXPERIMENTAL_LANGUAGE_FEATURE = 'experimental/language-feature';
 
+export const constraintListsShouldBeUsedWithCaution = (node: SdsConstraintList, accept: ValidationAcceptor): void => {
+    accept('warning', 'Constraint lists & constraints are experimental and may change without prior notice.', {
+        node,
+        keyword: 'where',
+        code: CODE_EXPERIMENTAL_LANGUAGE_FEATURE,
+    });
+};
+
 export const indexedAccessesShouldBeUsedWithCaution = (node: SdsIndexedAccess, accept: ValidationAcceptor): void => {
     if (hasContainerOfType(node.$container, isSdsIndexedAccess)) {
         return;
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
index 837e350df..b55f3ead8 100644
--- a/packages/safe-ds-lang/src/language/validation/safe-ds-validator.ts
+++ b/packages/safe-ds-lang/src/language/validation/safe-ds-validator.ts
@@ -27,6 +27,7 @@ import {
 import { singleUseAnnotationsMustNotBeRepeated } from './builtins/repeatable.js';
 import { annotationCallMustHaveCorrectTarget, targetShouldNotHaveDuplicateEntries } from './builtins/target.js';
 import {
+    constraintListsShouldBeUsedWithCaution,
     indexedAccessesShouldBeUsedWithCaution,
     literalTypesShouldBeUsedWithCaution,
     mapsShouldBeUsedWithCaution,
@@ -221,7 +222,7 @@ export const registerValidationChecks = function (services: SafeDsServices) {
             classMustNotInheritItself(services),
         ],
         SdsClassBody: [classBodyShouldNotBeEmpty],
-        SdsConstraintList: [constraintListShouldNotBeEmpty],
+        SdsConstraintList: [constraintListsShouldBeUsedWithCaution, constraintListShouldNotBeEmpty],
         SdsDeclaration: [
             nameMustNotStartWithCodegenPrefix,
             nameShouldHaveCorrectCasing,
diff --git a/packages/safe-ds-lang/tests/resources/validation/experimental language feature/constraint lists/main.sdstest b/packages/safe-ds-lang/tests/resources/validation/experimental language feature/constraint lists/main.sdstest
new file mode 100644
index 000000000..d76b39b09
--- /dev/null
+++ b/packages/safe-ds-lang/tests/resources/validation/experimental language feature/constraint lists/main.sdstest	
@@ -0,0 +1,4 @@
+package tests.validation.experimentalLanguageFeature.constraintLists
+
+// $TEST$ warning "Constraint lists & constraints are experimental and may change without prior notice."
+fun myFunction() »where« {}