handle invalid identifiers, fixes #980

src/main/java/carpet/script/utils/InputValidator.java

@@ -1,6 +1,9 @@
 package carpet.script.utils;
 
 import carpet.script.exception.InternalExpressionException;
+import net.minecraft.util.Identifier;
+import net.minecraft.util.InvalidIdentifierException;
+import org.lwjgl.system.CallbackI;
 
 import java.util.Locale;
 
@@ -13,4 +16,16 @@ public class InputValidator {
         return simplified;
     }
 
+    public static Identifier identifierOf(String string)
+    {
+        try
+        {
+            return new Identifier(string);
+        }
+        catch (InvalidIdentifierException iie)
+        {
+            throw new InternalExpressionException("Incorrect identifier format '"+string+"': "+iie.getMessage());
+        }
+    }
+
 }