Simplify null handling a bit in alternative code generation

src/main/java/org/sablecc/sablecc/GenerateAlternativeCodeForParser.java

@@ -80,7 +80,7 @@ public class GenerateAlternativeCodeForParser extends DepthFirstAdapter
   {
     if("null".equals(typeName))
     {
-      throw new IllegalArgumentException("Null values have no variable name");
+      return "null";
     }
     else if(typeName.startsWith("L"))
     {
@@ -156,16 +156,8 @@ public class GenerateAlternativeCodeForParser extends DepthFirstAdapter
 
         position = CG.getTermNumbers().get(term);
 
-        if("null".equals(type_name))
-        {
-          macros.apply(file, "ParserNewBodyListAddNull", null);
-        }
-        else
-        {
         macros.apply(file, "ParserNewBodyListAdd", new String[] {getVariableName(type_name, position)});
       }
-
-      }
       if (popCount > 0) {
         // The nodeArrayList variables are numbered starting at 1, so the first popped variable has the number popCount and not popCount-1.
         macros.apply(file, "ParserNewCheck", new String[] {String.valueOf(popCount)});
@@ -344,14 +336,7 @@ public class GenerateAlternativeCodeForParser extends DepthFirstAdapter
           type_name = lookupInternalTypeName(term);
           position = CG.getTermNumbers().get(term);
 
-          if(type_name.equals("null"))
-          {
-            macros.apply(file, "ParserNewBodyParam", new String[] {isNotTheFirstParam+"null"});
-          }
-          else
-          {
           macros.apply(file, "ParserNewBodyParam", new String[] {isNotTheFirstParam + getVariableName(type_name, position)});
-          }
 
           isNotTheFirstParam = ", ";
         }

src/main/resources/org/sablecc/sablecc/parser.txt

@@ -386,11 +386,6 @@ Macro:ParserNewBodyListAdd
 
 $
 
-Macro:ParserNewBodyListAddNull
-        nodeList.add(null);
-
-$
-
 Macro:ParserNewCheck
         checkResult(nodeList.get(0), nodeArrayList1, nodeArrayList$0$);