feat: validate impurity reasons of overriding methods (#774)

Closes #665

### Summary of Changes

Show an error if the impurity reasons of an overriding method are not a
subset of the impurity reasons of the overridden method.

package.json

@@ -24,14 +24,14 @@
         "@semantic-release/changelog": "^6.0.3",
         "@semantic-release/exec": "^6.0.3",
         "@semantic-release/git": "^10.0.1",
-        "@semantic-release/npm": "^11.0.0",
+        "@semantic-release/npm": "^11.0.1",
         "@vitest/coverage-v8": "^0.34.6",
         "@vitest/ui": "^0.34.6",
         "concurrently": "^8.2.2",
         "conventional-changelog-conventionalcommits": "^7.0.2",
         "esbuild": "^0.19.5",
         "esbuild-plugin-copy": "^2.1.1",
-        "semantic-release": "^22.0.6",
+        "semantic-release": "^22.0.7",
         "shx": "^0.3.4",
         "typescript": "^5.2.2",
         "vitest": "^0.34.6"

packages/safe-ds-cli/package.json

@@ -43,10 +43,10 @@
         "@safe-ds/lang": ">=0.3.0",
         "chalk": "^5.3.0",
         "commander": "^11.1.0",
-        "langium": "^2.1.0"
+        "langium": "^2.1.2"
     },
     "devDependencies": {
-        "@types/node": "^18.18.8"
+        "@types/node": "^18.18.9"
     },
     "engines": {
         "node": ">=18.0.0"

packages/safe-ds-lang/package.json

@@ -45,13 +45,13 @@
     "dependencies": {
         "chevrotain": "^11.0.3",
         "glob": "^10.3.10",
-        "langium": "^2.1.0",
+        "langium": "^2.1.2",
         "source-map": "^0.7.4",
         "vscode-languageserver": "^9.0.1",
         "vscode-languageserver-textdocument": "^1.0.11"
     },
     "devDependencies": {
-        "@types/node": "^18.18.8",
+        "@types/node": "^18.18.9",
         "langium-cli": "^2.1.0",
         "true-myth": "^7.1.0"
     },

packages/safe-ds-lang/src/helpers/collectionUtils.ts

@@ -62,6 +62,25 @@ export const isEmpty = (iterable: Iterable<unknown>): boolean => {
     return iterable[Symbol.iterator]().next().done === true;
 };
 
+/**
+ * Returns whether `set1` and `set2` contain the same values.
+ */
+export const isEqualSet = <T>(set1: Set<T>, set2: Set<T>): boolean => {
+    return set1.size === set2.size && isSubset(set1, set2);
+};
+
+/**
+ * Returns whether `set1` is a subset of `set2`.
+ */
+export const isSubset = <T>(set1: Set<T>, set2: Set<T>): boolean => {
+    for (const value of set1) {
+        if (!set2.has(value)) {
+            return false;
+        }
+    }
+    return true;
+};
+
 /**
  * Returns the last element of the array, or `undefined` if the array is empty.
  */