1 files changed, 16 insertions, 1 deletions
diff --git a/src/main/java/sevenUnits/unit/UnitDatabase.java b/src/main/java/sevenUnits/unit/UnitDatabase.java
index 58c5cac..05c31c4 100644
--- a/src/main/java/sevenUnits/unit/UnitDatabase.java
+++ b/src/main/java/sevenUnits/unit/UnitDatabase.java
@@ -1501,7 +1501,13 @@ public final class UnitDatabase {
 								unitName));
 					}
 				}
-				this.addUnitSet(name, units);
+				
+				try {
+					this.addUnitSet(name, units);
+				} catch (final IllegalArgumentException e) {
+					System.err.printf("Parsing error on line %d:%n", lineCounter);
+					throw e;
+				}
 			} else {
 				// it's a unit, get the unit
 				final Unit unit;
@@ -1525,6 +1531,15 @@ public final class UnitDatabase {
 	 * @since 2024-08-16
 	 */
 	public void addUnitSet(String name, List<LinearUnit> value) {
+		if (value.isEmpty())
+			throw new IllegalArgumentException("Unit sets must not be empty.");
+		for (final LinearUnit unit : value.subList(1, value.size())) {
+			if (!Objects.equals(unit.getDimension(), value.get(0).getDimension()))
+				throw new IllegalArgumentException(
+						"Unit sets must be all the same dimension, " + value
+								+ " is not.");
+		}
+		
 		this.unitSets.put(name, value);
 	}