1 files changed, 28 insertions, 5 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/naming/NamingUtil.java b/subprojects/language/src/main/java/tools/refinery/language/naming/NamingUtil.java
index 1647d4e7..feae5ebb 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/naming/NamingUtil.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/naming/NamingUtil.java
@@ -1,21 +1,24 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2021-2024 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
 package tools.refinery.language.naming;
 
+import org.eclipse.xtext.naming.QualifiedName;
+
 import java.util.regex.Pattern;
 
 public final class NamingUtil {
         private static final String SINGLETON_VARIABLE_PREFIX = "_";
-        
-        private static final Pattern ID_REGEX = Pattern.compile("[_a-zA-Z][_0-9a-zA-Z]*");
+        public static final QualifiedName ROOT_NAME = QualifiedName.create("");
+
+        private static final Pattern ID_REGEX = Pattern.compile("[_a-zA-Z]\\w*");
 
         private NamingUtil() {
                 throw new IllegalStateException("This is a static utility class and should not be instantiated directly");
         }
-        
+
         public static boolean isNullOrEmpty(String name) {
                 return name == null || name.isEmpty();
         }
@@ -23,8 +26,28 @@ public final class NamingUtil {
         public static boolean isSingletonVariableName(String name) {
                 return name != null && name.startsWith(SINGLETON_VARIABLE_PREFIX);
         }
-        
+
+        // This method name only makes sense if it checks for the positive case.
+        @SuppressWarnings("BooleanMethodIsAlwaysInverted")
         public static boolean isValidId(String name) {
                 return name != null && ID_REGEX.matcher(name).matches();
         }
+
+        public static boolean isFullyQualified(QualifiedName name) {
+                return name.startsWith(ROOT_NAME);
+        }
+
+        public static QualifiedName stripRootPrefix(QualifiedName name) {
+                if (name == null) {
+                        return null;
+                }
+                return isFullyQualified(name) ? name.skipFirst(ROOT_NAME.getSegmentCount()) : name;
+        }
+
+        public static QualifiedName addRootPrefix(QualifiedName name) {
+                if (name == null) {
+                        return null;
+                }
+                return isFullyQualified(name) ? name : ROOT_NAME.append(name);
+        }
 }